Fish Canning Handbook

Fish Canning Handbook

Fish Canning Handbook Edited by

Les Bratt Consultant in Food Technology Cleeve Prior, Worcester, UK

A John Wiley & Sons, Ltd., Publication

This edition first published 2010
C 2010 Blackwell Publishing Ltd Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing programme has been merged with Wiley’s global Scientific, Technical, and Medical business to form Wiley-Blackwell. Registered office John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom Editorial offices 9600 Garsington Road, Oxford, OX4 2DQ, United Kingdom 2121 State Avenue, Ames, Iowa 50014-8300, USA For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book, please see our website at www.wiley.com/wiley-blackwell. The right of the author to be identified as the author of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Library of Congress Cataloging-in-Publication Data Fish canning handbook / edited by Les Bratt. p. cm. Includes bibliographical references and index. ISBN 978-1-4051-8099-3 (hardback : alk. paper) 1. Canned foods–Sterilization. 2. Fishes–Preservation. 3. Canning and preserving. 4. Fishery products–Microbiology. 5. Canned fish products–Safety regulations–Europe. 6. Canned fish products–Safety regulations–North America. I. Bratt, L. (Les) TP371.35.F57 2010 664 .942–dc22 2010003296 A catalogue record for this book is available from the British Library. R Inc., New Delhi, India Set in 10/12 pt Times by Aptara
Printed in Singapore

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2010

Contents

List of contributors Preface: review of the market for, and sources of, canned fish 1 Legal requirements for producers selling canned fish into Europe John Hammond 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18

Introduction Imports into the EU General food law Product-specific controls Hygiene rules Fishery products from outside the EU Identification marking Microbiological criteria Labelling Lot marking Food contact materials Additives Flavourings Contaminants Pesticides Veterinary medicinal products Weights and measures Warning References

2 Legal requirements for producers selling canned fish into North America Kenneth Lum 2.1 2.2 2.3 2.4 2.5 2.6 2.7

Introduction Canned fish description Why are regulations necessary? Legal requirements and food safety Regulatory systems in Canada and the United States Canadian requirements United States requirements

3 HACCP systems for ensuring the food safety of canned fish products Alan Williams 3.1 3.2

Introduction The HACCP Principles

xi xiii 1 1 2 2 4 6 8 10 10 11 20 22 24 25 26 26 27 28 29 29 32 32 32 33 33 34 34 43 51 51 52

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3.3 3.4 3.5 3.6 3.7

Prerequisite programmes How to set up and conduct an HACCP study for canned fish products Implementation ISO 22000 Conclusions References Appendix 1: Useful websites (for HACCP Guidance and including generic HACCP plans in some cases) Appendix 2: Modular HACCP approach for the canning of tuna products, showing typical activities within each module Appendix 3: Example of a tabular documentation format for prerequisite programmes Appendix 4: Extract from a non-tabular format HACCP plan approach for can seaming (CCP 2) Appendix 5: Extract of a tabular HACCP Chart for CCP 3 sterilisation and CCP 4 in the generic fish canning flow diagram

4 National and international food safety certification schemes Harriet Simmons 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

Introduction Food safety legislation Food safety management systems Certification: A brief overview Hazard analysis critical control points The Global Food Safety Initiative A comparison of major global certification programmes for food safety Summary of comparison of global certification programmes

5 Fish quality Tony Garthwaite 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10

Introduction Important fish species Pollution aspects Handling and transport Spoilage factors Reception and testing Storage Defrosting frozen fish Fish preparation Chemical indicators of quality References

6 Design and operation of frozen cold stores Stephen J. James and Christian James 6.1 Introduction 6.2 Factors affecting frozen storage life

52 54 74 74 74 75 77 78 79 80 82 85 85 85 85 86 88 90 100 100 102 102 102 104 106 106 111 114 116 121 130 130 132 132 133

Contents

6.3 6.4 6.5 6.6

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Cold store design Specification and optimisation of cold stores Thawing Conclusions References

140 143 145 149 150

7 Packaging formats for heat-sterilised canned fish products Bev Page

151

7.1 7.2 7.3 7.4

Overview of the basic materials used for heat-sterilised fish packaging Metal cans for heat sterilised-fish products Plastic containers for heat-sterilised fish products Glass containers for heat-sterilised fish products Further reading

151 151 177 177 178

8 Retorting machinery for the manufacture of heat-sterilised fish products Claude Vincent

179

8.1 8.2 8.3 8.4 8.5 8.6 8.7

Introduction Retorting equipment available Technical features of horizontal batch retorts General arrangement of a sterilising plant Utilities required for batch retorts The different usages of a retort Legal steps to be taken when installing a new retort

9 Management of thermal process Nick May 9.1 9.2 9.3 9.4 9.5 9.6 9.7

10

Role of the thermal process manager Documentation of thermal process requirements Maintaining and calibration of key instrumentation Training of key staff Review of production records Managing non-conformance (process deviations) Conclusion References

Principal causes of spoilage in canned fish products Joy Gaze 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8

The quality of raw materials Hygiene and good manufacturing practice Potential spoilage issues associated with canned fish products Typical causes of spoilage in canned fish products Types of spoilage Microbiological examination of suspect spoilt cans Microbiological investigations – decision criteria Conclusion References

179 180 195 200 203 207 208 210 210 211 213 214 215 215 217 217 218 218 219 219 220 221 223 223 223 224

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Commercial sterility and the validation of thermal processes Geoff Shaw

225

11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9 11.10 11.11 11.12 11.13

225 226 228 228 229 229 230 231 231 233 234 235 236 236 237

Introduction Temperature measurement systems Processing vessels Temperature distribution Retort survey Test loading Data analysis Heat penetration measurement Commercial sterility and lethality General method Heat penetration experimental methods Flexible packaging Future developments and information References Other sources of information

The quality department in a fish cannery Leila Radi

238

12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 12.10 12.11 12.12 12.13

238 238 239 244 246 246 247 247 248 248 249 249 250 250 250

Avant-propos The organisation and the scope of operations of the quality department Quality assurance for the management of pre-requisite measures Quality control Establishment of a quality plan Standard quality procedures Training of quality staff against procedures Handling of non-conforming materials Establishment and monitoring of corrective actions Legislative compliance Research and development Security Conclusion Acknowledgement References

The laboratory in a fish canning factory Linda Nicolaides and Les Bratt 13.1 Laboratory facilities 13.2 Chemical analyses 13.3 Microbiological testing 13.4 Analysis required for cannery water and retort cooling water 13.5 Swab testing 13.6 Incubation tests 13.7 Sterility tests 13.8 Laboratory accreditation Further reading

251 251 254 255 256 256 257 257 260 260

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Cleaning and disinfection in the fish canning industry Peter Littleton

262

14.1 14.2 14.3 14.4 14.5 14.6 14.7 14.8 14.9 14.10 14.11 14.12 14.13 14.14 14.15 14.16 14.17

262 262 264 265 270 271 272 273 274 274 275 275 277 278 279 279 280 282

Introduction The cleaning process Principles of cleaning Open plant cleaning Floor cleaning Tray and rack washing machines Principles of disinfection Factors affecting disinfectant effectiveness Choosing the right disinfectant Where to disinfect Types of disinfectants Oxidising disinfectants Non-oxidising disinfectants Effects of time and concentration Specific issues relating to fish canning operations Cleaning management Cleaning programme References

The canning factory Les Bratt 15.1 15.2 15.3 15.4 15.5

Index

The fish canning factory: Introduction Site selection Factory design and construction The principal areas of the factory Services References and suggestions for further reading

283 283 283 284 289 296 298 299

List of contributors

Les Bratt Les Bratt (Food Technology) Ltd, Cleeve Prior, Worcestershire, UK

Nick May Campden BRI, Chipping Campden, Gloucestershire, UK

Tony Garthwaite Consultant Food Technologist, TG Associates, Grimsby, UK

Linda Nicolaides Food Safety Specialist, Natural Resources Institute, Greenwich, UK

Joy Gaze Microbiology Department, Campden BRI, Chipping Campden, Gloucestershire, UK

Bev Page Packaging Consultant, Ravenshead, Nottingham, UK

John Hammond Campden BRI, Chipping Campden, Gloucestershire, UK

Leila Radi International Quality Control Corporation, Rabat, Morocco

Christian James Food Refrigeration and Process Engineering Research Centre (FRPERC), The Grimsby Institute (GIFHE), Grimsby, Lincolnshire, UK

Geoff Shaw Ellab UK Limited, Bawburgh, Norfolk, UK

Stephen J. James Food Refrigeration and Process Engineering Research Centre (FRPERC), The Grimsby Institute (GIFHE), Grimsby, Lincolnshire, UK Peter Littleton Technical Services Manager, Holchem Laboratories Ltd, Haslingden, Rossendale, Lancashire, UK Kenneth Lum GMA/Food Products Association, Center for Northwest Seafood, Seattle, WA, USA

Harriet Simmons Technical Director for the Food Inspection Services, National Britannia Ltd, Caerphilly Business Park, Caerphilly, UK Claude Vincent STERIFLOW S.A.S., Paris, France Alan Williams Department of Food Manufacturing Technologies, Campden BRI, Chipping Campden, Gloucestershire, UK

Preface: review of the market for, and sources of, canned fish

Canning is a well-established and traditional means of providing food which is stable at ambient temperatures, has long shelf life and in consequence is eminently suitable for world-wide distribution. Canned fish is therefore exported from countries all over the world into the consumer markets of Europe and North America. The manufacturing of canned fish has provided, and continues to provide much-needed employment, individual incomes and the means for foreign currency exchange for developing countries, particularly in Southeast Asia, South America and the Indian Ocean. Within the past 20 years or so there have been noticeable changes within the canned fish industry. The increased emphasis on food safety has given rise to better understanding of the process of heat sterilisation, together with ever-sophisticated equipment providing the means to measure that sterilisation; the introduction of the ISO 9000 Standard has led to the better organisation of Quality Management Systems in which responsibilities are better defined and understood; modern processing equipment with microprocessor control has provided the better regulation of temperatures and pressures during thermal processing; and the widespread adoption of HACCP systems has allowed companies to identify and concentrate their efforts on those matters contributing to product safety. The changes that have occurred within the industry have also been due to long-term pressure from the retail and trading companies who provide audit of, and technical help to, their suppliers in order to ensure that food provided to their customers is safe. In recent years we have seen the introduction of numerous industry-led standards such as the International Food Standard or the British Retail Consortium Standard the requirements of which manufacturing companies are required to meet if they wish to supply to the major purchasing organisations in Europe or North America. The introduction of new legislation has also taken place particularly within Europe. The three basic food hygiene regulations are:

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852/2004 on the hygiene of foodstuffs; 853/2004 laying down specific rules for food of animal origin; and 854/2004 laying down the specific rules for the organisation of official controls on animal products intended for human consumption.

Food business operators are effectively required to put in place, implement and maintain a permanent procedure, or procedures, based on HACCP principles. Canned fish is seen as intrinsically healthy, convenient and tasty. The UK market for canned fish is currently worth some £474 million at retail, equivalent to 108 624 tonnes. Standard tuna products at 55% comprise the largest sector of this market, canned salmon is second with 20%, and the oily fish, sardines, mackerels and pilchards together comprise 13.8%. Added value tuna products now account for 5% of the canned fish category and have been a key driver for growth in recent years. Product innovation has been instrumental in providing new products launched to meet incremental consumer needs identified through consumer research.

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This handbook is intended as a technical reference and help for all those fish canning companies wishing to meet the demands of the technically discerning retail and trading organisations and thus greatly increase their opportunities for export. Les Bratt Data source: AC Nielsen Scantrack 52w/e 24th January 2009.

1

Legal requirements for producers selling canned fish into Europe

John Hammond

1.1 INTRODUCTION The European Union (EU) represents a single market of nearly 500 million consumers across 27 Member States. Whilst large, it is less than half the size of India and a little more than one third of the size of China. The need to compete effectively with such global economies has been a major factor in the expansion of the EU over the last 50 years, from an initial Economic Community of just six Member States. The EU remains first and foremost a ‘Common Market’ and in pursuit of this most of the food laws that apply in the 27 individual Member States have been developed and agreed by the EU. As with most food law in well-developed market economies, the main functions of the controls are:

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To protect the health of people, animals and plants; To ensure that consumers are not misled about the composition and origin of the food that they purchase; To support fair competition in order that well run businesses that meet their legal obligations are not put at a competitive disadvantage in comparison with companies that take a less rigorous approach to compliance; and To promote free trade so that goods legally manufactured or imported into one Member State can then move freely across the entire EU.

EU food law is part of a wider legislative framework that is designed to secure the free movement of people, services, capital and goods, including food and feed, throughout its Member States. The French term Acquis Communautaire is often used to denote the various treaties, regulations and directives passed by the European institutions, as well as judgements reached by the European Court of Justice. The elements that control the production and marketing of food and feed are described in this chapter. But first it is necessary to understand and distinguish the different types of EU legal instruments. Much of the earlier body of EU food law was developed in the form of Directives. As the term suggests, they directed Member State governments to give effect to the detailed requirements set out in the Directive, but crucially left Member States with the flexibility to adopt their own national legislation to achieve this. One potential disadvantage of this approach was that Member States might implement the Directive into their national legislation slightly differently, and that any divergences might then impede the free movement of goods, one of the original objectives of developing the legislation.

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For this reason, therefore, in recent years most EU food laws have been made in the form of Regulations. These apply fully and equally in all Member States without the need for implementing legislation and thus without the danger of national variations. All that is normally required in national legislation is a simple legal instrument to provide for the execution and enforcement of the EU Regulation and to put in place a system of sanctions in cases of non-compliance.

1.2

IMPORTS INTO THE EU

Against this background, it is clear that the rules that apply to imports from countries outside the EU, often termed ‘third countries’, are vital to ensure the most complete possible protection of EU consumers and industries. The controls placed on such imports differ according to the type of food concerned. Commission Decision 2007/275/EC (European Union, 2007a) draws up a list of animals and animal products, including fish that are subject to controls at border inspection posts. Commission Decision 2001/881/EC (European Union, 2001b), as amended, lists the designated Border Inspection Posts where official veterinarians undertake veterinary checks on live animals and animal products in conjunction with the competent authorities. Each year, the infrastructure, equipment and working of each post are inspected by a Commission veterinary expert in cooperation with the competent national authorities. Border Inspections Post checks are carried out in close cooperation with customs officials; the list of products subject to inspection is defined by reference to the combined nomenclature (CN) established by Council Regulation (EEC) No. 2658/87 (European Union, 1987) on the tariff and statistical nomenclature. The following products are specifically listed under, amongst others, the following principal headings:

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16 04 Prepared or preserved fish; caviar and caviar substitutes prepared from fish eggs; and 16 05 Crustaceans, molluscs and other aquatic invertebrates, prepared or preserved.

At Border Inspection Posts, the product’s identity and documentation are checked and some physical checks are also made, for example, on the product’s packaging and labelling: laboratory testing may also be undertaken. Consignments of food found not to comply with EU legislation are either destroyed or, under certain conditions, re-despatched within 60 days. Because products of non-animal origin are inherently less hazardous than those of animal origin, the controls on their importation into the EU are less strict. In broad terms, such products must meet the safety requirements of the EU General Food Law Regulation; they must not be unsound or unwholesome; and they must comply with any other specific legislative controls.

1.3 GENERAL FOOD LAW Despite the agreement of many product and subject-specific EU food controls, until 2002 there was no EU instrument that laid down broad principles governing food and feed in general and their safety in particular. To fulfil this need, and because a number of different concepts, principles

Legal requirements for producers selling canned fish into Europe

3

and procedures had been included in pre-existing national food laws, Council Regulation (EC) No. 178/2002 (European Union, 2002a), laying down the general principles and requirements of food law, was adopted. This instrument also established a body charged with undertaking risk assessment known as the European Food Safety Authority (EFSA). Under Council Regulation 178/2002, food must not be placed on the market if it is unsafe. Food is deemed to be ‘unsafe’ if it is considered to be:

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Injurious to health; or Unfit for human consumption. In deciding whether or not food is ‘unsafe’, it is necessary to take into account:

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The normal conditions of use of the food by the consumer and at each stage of production, processing and distribution; and The information provided to the consumer, including information on the label or other information generally available to the consumer concerning the avoidance of specific adverse health effects from a particular food or category of foods.

In determining whether a food is ‘injurious to health’, the Regulation goes on to say that it is necessary to consider:

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Not only the probable immediate and/or short-term and/or long-term effects of that food on the health of the person consuming it, but also on subsequent generations; The probable cumulative toxic effects; and The particular health sensitivities of a specific category of consumers where the food is intended for that category of consumers.

Furthermore, food business operators at all stages of production, processing and distribution must ensure that foods satisfy the requirements of food law which are relevant to their activities and must verify that such requirements are met. Whilst the general food safety requirements would, in almost all respects, have been preceded by earlier national legislation in each EU Member State, the Regulation did introduce more novel requirements for traceability and for the withdrawal and/or recall of unsafe food. Specifically, the Regulation requires that the traceability of food and any other substance intended to be, or expected to be, incorporated into a food to be established at all stages of production, processing and distribution. Although at first reading this may appear to be onerous, in fact it is a simple requirement for food business operators to be able to identify any person who has supplied them with a food or any substance intended to be, or expected to be incorporated into a food or feed. Similarly, food business operators must be able to identify businesses (but not, crucially, the ultimate consumer) to which they have supplied their products. In each case, this information must be made available to the competent authorities on demand. The requirement thus falls far short of requiring full internal traceability, whereby it would be necessary to identify which consignments and deliveries of raw materials and ingredients had been incorporated into what batches of finished food. The second new responsibility placed on food business operators by Council Regulation 178/2002 was for those who consider or have reason to believe that a food which they have imported, produced, processed, manufactured or distributed is not in compliance with the food safety requirements. In

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such cases, where the food has left the immediate control of that food business operator, the food business operator must immediately initiate procedures to withdraw the food from the market and inform the competent authorities. Where the product may have reached the consumer, the operator must effectively and accurately inform the consumers of the reason for its withdrawal and, if other measures are not sufficient to protect public health, recall from consumers products already supplied to them. One such case in 2007 involved the withdrawal of canned fish liver containing very high levels of dioxins and in particular dioxin-like polychlorinated biphenyls (PCBs). Although no maximum level had then been established for these substances in fish liver and processed products thereof, the concerned competent authorities prohibited the marketing of the products because they were deemed to be unsafe.

1.4 PRODUCT-SPECIFIC CONTROLS In its earliest years, the then European Economic Community comprised a much smaller and arguably more coherent group of six nations. At that time, a key objective of food law was to reach Community-wide agreement on the composition and labelling of a wide range of internationally traded foodstuffs. As the Community enlarged, however, the food-processing industries and the culinary traditions of the various Member States became ever more varied. As a consequence, it became much harder to reach agreement on compositional and related controls governing the production and marketing of particular types of food. In the face of such difficulties and in the wake of an important judgement of the European Court of Justice in the Cassis de Dijon (European Court of Justice, 1979) case, a new approach became necessary. In 1982, therefore, the European Commission (in effect the civil service of the EU) abandoned further plans to harmonise food standards in this way. Instead it suggested that, as a general principle, products legally manufactured and marketed in one Member State should, provided they were properly and informatively labelled, be capable of being traded freely across the EU. Initially, the new approach was largely forward looking. Although, since then, there have been initiatives designed to modernise and simplify earlier controls, notably as part of the Simplification of the Internal Market (SLIM) (SLIM, 1996) Programme, a number of compositional standards remain in place, including those controlling preserved sardines and sardine-type products and separately canned tuna and bonito. Both were developed under Regulation (EEC) No. 3796/81 (European Union, 1981) on the common organisation of the market in fishery products, which allows for Community-wide marketing standards for fishery products to be developed, particularly to ensure that products of unsatisfactory quality are marketed as well as to facilitate trade based on fair competition. Council Regulation (EEC) No. 2136/89 (European Union, 1989c) as amended by Commission Regulation (EC) No. 1181/2003 (European Union, 2003b) defines the standards governing the marketing of preserved sardines and the trade descriptions for preserved sardines and preserved sardine-type products marketed in the EU. Only products covered by CN codes 1604 13 11, 1604 13 19 and ex 1604 20 50, prepared exclusively from fish of the species Sardina pilchardus Walbaum, pre-packaged with any appropriate covering medium in a hermetically sealed container and sterilised may be marketed as preserved sardines.

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The Regulations prescribe and define the presentations in which preserved sardines may be marketed (‘sardines’, ‘sardines without bones’, ‘sardines without skin or bones’, ‘sardine fillets’, ‘sardine trunks’ or any other form clearly distinct from these), names for certain covering media, quality criteria and labelling requirements. The 2003 amendment was designed to ensure that the labelling of preserved products marketed and presented in the same way as preserved sardines made a clear distinction between the two, so that consumers would not be misled. The definition of sardine-type products was those marketed and presented in the same way as preserved sardines and prepared from fish of the following species: (a) (b) (c) (d) (e) (f) (g) (h) (i) (j)

Sardinops melanosticus, S. neopilchardus, S. ocellatus, S. sagax and S. caeryleus; Sardinella aurita, S. brasiliensis, S. maderensis, S. longiceps and S. gibbosa; Clupea harengus; Sprattus sprattus; Hyperlophus vittatus; Nematalosa vlaminghi; Etrumeus teres; Ethmidium maculatum; Engraulis anchoita, E. mordax and E. ringens; and Opisthonema oglinum.

The name ‘sardines’ can be used only in the marketing of preserved sardine-type products if it is in combination with one of the above scientific names of the species. Common names not including the word ‘sardines’ may continue to be used for the marketing of sardine-type products in compliance with the food-labelling directive. A second such Regulation, Council Regulation (EEC) No. 1536/92 (European Union, 1992), defines the standard governing the marketing of preserved tuna and bonito in the EU. The trade descriptions tuna and bonito are reserved for products falling within the following CN codes:

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Tuna: CN codes 1604 14 10 and ex 1604 20 70; and Bonito: CN codes 1604 14 90, ex 1604 20 50, 1604 19 30, ex 1604 20 70, ex 1604 19 99 and ex 1604 20 90

and prepared exclusively from fish of one of the following genera:

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Tuna – Species of the genus Thunnus (a) Albacore or long-finned tuna (Thunnus alalunga) (b) Yellowfin tuna (T. (neothunnus) albacores) (c) Bluefin tuna (T. thynnus) (d) Bigeye tuna (T. (parathunnus) obesus) (e) Other species of the genus Thunnus. – Skipjack or stripe-bellied tuna (Euthynnus (Katsuwonus) pelamis).

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Fish Canning Handbook

Bonito – Species of the genus Sarda (a) Atlantic bonito (Sarda sarda) (b) Pacific bonito (S. chiliensis) (c) Oriental bonito (S. orientalis) (d) Other species of the genus Sarda. – Species of the genus Euthynnus, with the exception of the species E. (Katsuwonus) pelamis (a) Atlantic little tuna (E. alleteratus) (b) Eastern little tuna (E. affinis) (c) Black skipjack (E. lineatus) (d) Other species of the genus Euthynnus. – Species of the genus Auxis (a) Frigate mackerel (Auxis thazard) (b) A. rochei.

The Regulations prescribe the presentation in which tuna and bonito may be marketed and the description of the presentation to accompany ‘tuna’ or ‘bonito’ in the name of the food (i.e. solid [declaration optional], chunks, fillets, flakes, grated/shredded tuna and any other form of presentation clearly identified in the product’s name). The conditions for the use of covering media, to be declared as part of the product’s name, are laid down. For example, the word ‘natural’ may be used only for media using the liquid exuding from the fish during cooking as the covering medium, a saline solution or water, possibly with the addition of herbs, spices or flavourings. In addition, the proportion by weight of fish in the container after sterilisation relative to the net weight must be at least 70%. The word ‘natural’ may be used only to describe a preserved tuna or bonito product as a whole when the ‘natural’ criteria for the covering medium are met and the product is presented in ‘solid’ form, as ‘chunks’ or as ‘fillets’. Where the covering medium is not described as ‘natural’, the proportion by weight of fish in the container after sterilisation relative to the net weight must be at least 65%, but only at least 25% in the case of forms of presentation other than as solid, chunks, fillets, flakes or grated/shredded tuna.

1.5 HYGIENE RULES EC hygiene legislation was consolidated and simplified in 2004 through a series of regulations, the most important of which are:

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Regulation (EC) No. 852/2004 (European Union, 2004a) on the hygiene of foodstuffs; Regulation (EC) No. 853/2004 (European Union, 2004b) laying down specific hygiene rules for foods of animal origin; Regulation (EC) No. 854/2004 (European Union, 2004c) laying down specific rules for the organisation of official controls on products of animal origin intended for human consumption; and Regulation (EC) No. 882/2004 (European Union, 2004d) on official controls performed to ensure the verification of compliance with feed and food law, animal health and animal welfare rules.

Legal requirements for producers selling canned fish into Europe

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The overall aim was to create a single, transparent hygiene policy applicable to all food and all food operators, together with effective instruments to manage food safety and potential food crises, throughout the food chain. The revised rules are based on the following key measures:

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Implementation of a ‘farm to table’ approach; Introduction of a ‘hazard analysis and critical control points’ (HACCP) system in all food sectors, except the primary sector; Registration or approval of certain food establishments; and Development of guides to good practice for hygiene and the application of HACCP principles.

Under Regulation (EC) No. 852/2004, food business operators must, as appropriate, adopt the following specific hygiene measures:

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Compliance with microbiological criteria for foodstuffs: since developed as Commission Regulation (EC) No. 2073/2005 (European Union, 2005c); Procedures necessary to meet targets set to achieve the objectives of the Regulation; Compliance with temperature control requirements; Maintenance of the cold chain; and Sampling and analysis.

The food business operators must also put in place, implement and maintain a permanent procedure based on HACCP principles. This applies to food business operators carrying out any stage of production, processing and distribution of food after primary production and associated operations. The Regulation also puts in place requirements for food premises, food preparation rooms, movable and/or temporary premises, transport, equipment, food waste, water supply, personal hygiene, foodstuffs, wrapping and packing of foodstuffs, heat treatment and training. Specifically, the following applies in relation to heat treatment of food placed on the market in hermetically sealed containers:

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Any heat treatment is to raise every part of the product to a given temperature for a given period of time and to prevent the product from becoming contaminated during the process; Food business operators must check regularly the main relevant parameters (particularly temperature, pressure, sealing and microbiology), including the use of automatic devices; and The process used should conform to an internationally recognised standard (e.g. for pasteurisation, ultra high temperature or sterilisation).

Regulation (EC) No. 853/2004 lays down supplementary specific rules on the hygiene of food of animal origin for food business operators involved in these sectors. It is important to appreciate that these are additional to the rules laid down in Regulation (EC) No. 852/2004, not replacements for them, and that the Regulation applies to unprocessed and processed products of animal origin. Products of animal origin mean:

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Food of animal origin, including honey and blood; Live bivalve molluscs, live echinoderms, live tunicates and live marine gastropods intended for human consumption; and Other animals destined to be prepared with a view to being supplied live to the final consumer.

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Establishments handling products of animal origin, including those involved in the production of fishery products, can operate only if a competent authority has approved them. The exceptions are establishments carrying out only:

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Primary production; Transport operations; The storage of products not requiring temperature-controlled conditions; or Retail operations other than those to which the Regulation otherwise applies.

EC guidance (European Commission, 2006) includes a non-exhaustive list of ‘unprocessed products of animal origin’ including fresh fishery products, live bivalve molluscs, live echinoderms, live tunicates and live marine gastropods. ‘Fresh’ with regard to fishery products means unprocessed fishery products, whether whole or prepared, including products purchased in a vacuum or in a modified atmosphere that have not undergone any treatment to ensure preservation other than chilling. Similarly, a non-exhaustive list of ‘processed products of animal origin’ is accompanied by an explanation that these are obtained by submitting raw materials to a process, such as heating, smoking, curing, maturing, drying or marinating, which leads to a substantial alteration of the initial product. Most importantly, however, the Regulation does not extend to foods containing both products of plant origin and processed products of animal origin, although clearly the products of animal origin used to prepare such foods must be obtained and handled in accordance with Regulation (EC) No. 853/2004. Food business operators must not use any substance other than potable water or, when Regulation (EC) No. 852/2004 or 853/2004 permits its use, clean water to remove surface contamination from products of animal origin, unless use of that substance has been approved. At present no such substances have been authorised. Food business operators may place products of animal origin manufactured in the Community on the market only if they have been prepared and handled exclusively in establishments: (a) That meet the requirements of Regulations (EC) No. 852/2004, and 853/2004, as appropriate, and other relevant requirements of food law; and (b) That the competent authority has registered or, where required, approved.

1.6 FISHERY PRODUCTS FROM OUTSIDE THE EU Food business operators importing fishery products from non-EU countries must ensure that: (a) The exporting country appears on a list, drawn up in accordance with Regulation (EC) No. 854/2004, of third countries, from which imports of that product are permitted; (b) The establishment from which the product was dispatched, and in which it was obtained or prepared, has been approved; (c) In the case of live bivalve molluscs, echinoderms, tunicates and marine gastropods, the production area appears on a list drawn up;

Legal requirements for producers selling canned fish into Europe

9

(d) The product satisfies the requirements of Regulation (EC) No. 853/2004, including the requirements on identification marking (see below), the requirements of Regulation (EC) No. 852/2004 and any import conditions laid down. In particular, Regulation (EC) No. 853/2004 contains specific requirements on the structure of vessels, landing sites, processing establishments and operational processes, freezing and storage; and (e) The requirements of Regulation (EC) No. 854/2004 concerning certificates and documents are met to ensure that they are a credible guarantee of public and animal health. When required, food business operators must ensure that certificates or other documents accompany consignments of products of animal origin. The following third countries are approved for the import of fishery products into the EU. In each case, specific factory vessels, fishery vessels and processing plants in which these exports can be handled and prepared are approved as appropriate. Algeria Albania Antigua and Barbuda Argentina Armenia Australia Bahamas Bangladesh Belarus Belize Brazil Canada Cape Verde Chile China Columbia Costa Rica Cote D’Ivoire Croatia Cuba Ecuador Egypt El Salvador Falkland Islands Faroe Islands French Polynesia Gabon Gambia Ghana Greenland

Grenada Guatemala Guinea Guyana Honduras Hong Kong India Indonesia Iran (Islamic Republic of) Jamaica Japan Kazakhstan Kenya Korea (Republic of) Madagascar Malaysia Maldives Mauritania Mauritius Mayotte Mexico Montenegro Morocco Mozambique Namibia Netherlands Antilles New Caledonia New Zealand Nicaragua Nigeria

Oman Pakistan Panama Papua New Guinea Peru Philippines Russian Federation Saudi Arabia Senegal Seychelles Singapore South Africa Sri Lanka St Pierre and Miquelon Suriname Taiwan Tanzania Thailand Tunisia Turkey Uganda Ukraine United Arab Emirates United States Uruguay Venezuela Vietnam Yemen Zimbabwe

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1.7 IDENTIFICATION MARKING Identification marks (and a similar scheme of health marks that apply only to carcases of fresh red meat) are applied to ensure the traceability of products of animal origin throughout the food supply chain. The identification must:

r r r

Indicate the name of the country in which the establishment is located. This may be written out in full or shown as a two-letter code in accordance with the relevant ISO standard (International Organization for Standardization, 2006); Indicate the approval number of the establishment, as allocated by the appropriate Competent Authority; and Be legible and indelible and the characters easily decipherable.

1.8 MICROBIOLOGICAL CRITERIA Commission Regulation (EC) No. 2073/2005 on microbiological criteria for foodstuffs applies to all food businesses involved in food production, processing and distribution including retail. Two types of microbiological criteria are laid down:

r r

A food safety criterion defines the acceptability of a product or a batch of foodstuff placed on the market and A process hygiene criterion which indicates the acceptable functioning of the production process. This type of criterion is not applicable to products placed on the market. Rather, it sets a level of contamination which, if exceeded, requires corrective actions in order to maintain the hygiene of the processing in compliance with food law.

The food safety criteria set down in the Regulation include two criteria for fishery products set out in Table 1.1. Results from histamine in fishery products from fish species associated with a high amount of histidine are satisfactory if:

r r r

The mean value observed is less than or equal to m; A maximum of c/n values observed are between m and M; No values observed exceed the limit of M.

Results are unsatisfactory if the mean value observed exceeds m, or more than c/n values are between m and M, or one or more values observed are greater than M. No process hygiene criteria are laid down for fishery products, other than for cooked crustaceans and molluscan shellfish, such as oysters, clams and winkles.

Legal requirements for producers selling canned fish into Europe Table 1.1

11

Food safety criteria for fishery products.

Food category Fishery products from fish species associated with a high amount of histidined

Microorganisms/ their toxins, metabolites Histamine

Sampling plana

Limitsb

Stage where the criterion applies

n

c

m

M

9e

1

100 mg/kg

200 mg/kg

High performance liquid chromatography (HPLC)

Products placed on the market during their shelf life

9

2

200 mg/kg

400 mg/kg

HPLCf

Products placed on the market during their shelf life

Examples: tuna, mackerel, sardines, mahi Fishery products which Histamine have undergone enzyme maturation treatment in brine, manufactured from fish species associated with a high amount of histidine

Analytical reference methodc

Example: anchovies a n,

number of units comprising the sample; c, number of sample units giving values more than m or between m and M. points 1.1–1.24 m = M. most recent edition of the standard shall be used. d Particularly fish species of the families: Scombridae, Clupeidae, Engraulidae, Coryfenidae, Pomatomidae and scomberesosidae. e Single samples may be taken at retail level. In such a case, the presumption laid down in Article 14(6) of Regulation (EC) No. 178/2002, according to which the whole batch should be deemed unsafe, shall not apply. f References: (1) Malle P., Valle M. and Bouquelet S. (1996) Assay of biogenic amines involved in fish decomposition. Journal of AOAC International , 79, 43–49. (2) Duflos G., Dervin C., Malle P. and Bouquelet S. (1999) Relevance of matrix effect in determination of biogenic amines in plaice (Pleuronectes platessa) and whiting (Merlangus merlangus). Journal of AOAC International , 82, 1097–1101. b For

c The

1.9

LABELLING

Food labelling in the EU is principally controlled by Council Directive 2000/13/EC (European Union, 2000b) (which consolidated an earlier and much-amended Directive 79/112/EEC) on the labelling, presentation and advertising of foodstuffs. It requires that the labelling information with which it is legally required to be labelled in a language that is readily understood by the consumer. (UK case law has determined that in practice this means the English language for products marketed in the UK.) The ‘General Food Labelling Requirement’ set out in the Directive applies to almost all food for human consumption including canned fish, other than preserved sardines, tuna and bonito which, as explained earlier, are subject to more specific regulations. These products are, however, subject to other controls on labelling set out in Directive 2000/13, notably those on claims; nutrition labelling, misleading descriptions; manner of marking or labelling; and intelligibility.

1.9.1 Name of food If a name for a food is prescribed by EU law, that name must be used for the food.

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Although a number of names are prescribed by law for certain fish species within Council Regulation (EC) No. 104/2000 (European Union, 2000a) and Commission Regulation (EC) No. 2065/2001 (European Union, 2001a ), these naming rules extend only to the sale of:

r r r r r r

Live fish; Fish chilled and frozen fish; Fish fillets and other fish meat (whether minced or not); Dried, salted or brined fish; Smoked fish; and Crustaceans (except crustaceans which are both cooked and peeled) and (molluscs) except cooked molluscs.

Thus, canned fish are outside their scope. Where there is no name prescribed by law, a customary name may be used. A customary name is one that over time has come to be accepted by consumers in the area where the food is sold, without the need for further explanation. An example in the UK might be Cullen Skink, a soup made from smoked haddock. If there is no name laid down by law and no customary name, or it is not used, a descriptive name must be used. The name of the product must be sufficiently precise to inform the purchaser of the true nature of the food, to enable it to be distinguished from products with which it could be confused and, where necessary, to include a description of its use. For example, ‘true nature’ means a clear and accurate description of the characteristics of the food but does not require a detailed description including all of the main ingredients. A trademark, brand name or fancy name cannot legally be regarded as the name of the food, however well recognised they may be. Although a scheme has been established within the EU to protect certain types of food names as Protected Designations of Origin, as Protected Geographical Indications or as Traditional Speciality Guaranteed, at present these extend only to certain types of agricultural products and foodstuffs. So, although it is possible to register names of qualifying fresh fish, molluscs, crustaceans and products thereof, no such facility exists for processed products.

1.9.2 Indication of treatment in the name of the food Where a purchaser could be misled by the omission of an indication that the food is in a particular physical condition, for example flaked, or has been subjected to a treatment, such as smoking, the legal name of the food must be coupled with such an indication. This could be particularly relevant to fish products incorporating minced fish.

1.9.3

Ingredient listing

Almost all manufactured foods are also required, when pre-packed, to carry a list of ingredients. These are defined as any substance, including any additive and any constituent of a compound ingredient, which is used in the preparation of the food and which is still present in the finished product. To simplify food labels, certain generic names listed may be used instead of more specific ingredient names, provided that any specified conditions are met.

Legal requirements for producers selling canned fish into Europe

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Amongst the permitted generic names are: Generic name

Ingredients

Conditions of use of generic name

Fish

Any species of fish

The label of the food must not refer to specific species of fish.

Herb, herbs or mixed herbs

Any herb or parts of a herb or combination of two or more herbs or parts of herbs

The proportion in the food must not exceed 2% by weight of the food.

Oil

Any refined oil other than olive oil

Oil must be accompanied by either the description animal or vegetable, as is appropriate, or an indication of the specific animal origin or the specific vegetable origin of the oil (as is appropriate). In the case of hydrogenated oil, the description hydrogenated must also be used.

Spice, spices or mixed spices

Any spice or any combination of two or more spices

The proportion in the food must not exceed 2%.

1.9.4

Allergen labelling requirements

Council Directive 2003/89/EC (European Union, 2003a) sets out requirements for the labelling of allergenic ingredients and ingredients derived from an allergenic ingredient. The requirement is to list specified allergens and, where pre-packed foods are made using these allergens, or their derivatives, a clear reference to the source allergen must be made in the ingredients list (where appropriate). The list of allergenic ingredients that must be declared in this way includes:

r r r

Crustaceans and products thereof; Fish and products thereof; and Molluscs and products thereof.

Although the legal requirement is for the word ‘fish’ to appear, the use of common names such as salmon, tuna and mackerel would normally be taken to indicate the presence of ‘fish’. The nature of any more exotic species should, however, be made clear. A similar approach applies in relation to the presence of crustaceans. Molluscs include oysters, squid, cockles, mussels, periwinkle and scallops. All added ingredients and components of added ingredients are covered by the requirements if they are present in the finished product, even in an altered form. This includes carry-over additives, any substances used as processing aids, and solvents and media for additives or flavourings. There are currently no statutory rules governing labelling for a possible low-level presence of allergens due to cross-contamination of foods. Advisory labelling on possible cross-contamination with allergens would normally be justified on the basis of a risk assessment applied to a responsibly managed operation. Generally, warning labels should only be used where there is a demonstrable and significant risk of allergen cross-contamination and should not be used as a substitute for good manufacturing practice.

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1.9.5

Quantitative ingredient declaration

To provide consumers with useful comparative information about potentially competing products prior to their purchase and as an alternative to the development of further compositional standards and reserved descriptions, rules for Quantitative Ingredient Declaration (QUID) have been introduced in the EU. The quantity of an ingredient or category of an ingredient used in the preparation of food must be indicated when:

r r r r

The name of the ingredient appears in the name of the food (mackerel in tomato sauce); The name of a category of ingredients appears in the name of the food (fish soup); The consumer usually associates an ingredient or category of ingredient with the name of the food (fish in Bouillabaisse); and The ingredient or category of ingredients concerned is emphasised on the labelling in words, pictures or graphics.

QUID is not, however, required where a product’s net drained weight is indicated along with its net weight as referred to in Directive 2000/13. This requires solid foods presented in a liquid medium to declare their drained net weight in addition to the net weight. ‘Liquid medium’ means the following, including in mixtures and also where frozen or quick frozen, provided that the liquid is merely an adjunct to the essential elements of the preparation and thus is not a decisive factor for purchase:

r r r r

Aqueous solutions of salts, food acids, sugars or other sweetening substances; Water; Brine; and Vinegar.

Guidance for the Verification of Drained Weight, Drained Washed Weight and Deglazed Weight and Extent of Filling of Rigid Food Containers has been published by WELMEC (2006). The exemption will not apply if, on mixed ingredient products, one or more ingredient was emphasised in some way, because the amount of that ingredient could not be calculated from the given weight indications. The quantity of an ingredient or category of ingredients is generally expressed as a proportion of the total food at the ‘mixing bowl’ stage. QUID declarations on products, the composition of which has been changed by cooking or other treatments involving the loss of moisture, may be based on the amount of the ingoing ingredient expressed as a percentage of the weight of the final product. Where this calculation leads to declarations exceeding 100%, the declaration should be replaced with statements giving the amount of the ingredient used to make 100 g or mL of the final product, for example, ‘Made with x grams of fish per 100 g’.

1.9.6

Date marking

Long-life products such as canned or jarred fish and fish products with a shelf life of more than 18 months are required to carry a durability indication in the form of ‘best before’ followed by the date up to and including which the food can reasonably be expected to retain its specific properties, if properly stored.

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Where the food has a shelf life of more than 18 months, the date may be expressed in terms of the year only if the words ‘best before’ are replaced by the words ‘best before end’, for example, ‘best before end 2010’. Where a food has a shelf life of less than 18 months, it may be expressed in terms of a month and a year only, for example ‘best before end December 2010’. Such declarations need to be followed by any storage conditions that need to be observed if the unopened food is to retain its specific properties up to the date indicated. In the case of canned food, it would be unlikely that any specific storage conditions would need to be specified. Such storage conditions relate to the food whilst it remains unopened. In addition to this, however, special storage conditions or conditions of use have to be given if the consumer needs to observe certain practices once the packaging of the food has been opened, for example ‘once open, remove from can, keep refrigerated and covered and consume within 3 days’. It is possible to ‘signpost’ a date mark, for example, to indicate that the best before date is stamped or printed onto the base or lid of a can. In this case words such as ‘for best before see can end’ would be appropriate.

1.9.7 Name and address It is also a requirement to indicate the name or business name and an address or registered office of either or both of:

r r

A manufacturer or packer; or A seller established within the EU.

This requirement enables consumers to contact a person responsible for the foodstuff and the details should therefore be sufficient to allow such contact to be made by post. Whilst customer care telephone numbers and website address can be supplied additionally, they cannot replace the postal address.

1.9.8

Origin marking

Particulars of the place of origin or provenance of a food are required where any indication or pictorial representation might mislead a consumer to a material degree as to the true origin or provenance of a food. Care is therefore required to ensure that the true place of origin is given if a food’s name, or its brand or trade name, includes a reference to a place in such a way which, when taken with other written illustrative information given on the label, could imply that the food comes from or has been made in a particular place or area. Where it is not possible to refer to a single country, information that is given should be as specific as possible, for example, by listed alternative supplier countries or groups of countries recognisable to consumers; even phrases like ‘origin will vary’ may be more helpful than no information at all.

1.9.9

Instructions for use

Instructions for use must be given if it would be difficult to make appropriate use of the food without them. Any instructions provided must be sufficiently detailed to enable appropriate preparation or use to be made of the food.

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1.9.10

Location of information

All of the labelling requirements are required to appear on the packaging (or on a label attached to the packaging or on a label that is clearly visible through the packaging). When the food is sold otherwise than to the ultimate consumer, for example to a caterer, then the details may be contained in the relevant commercial documents, providing it could be guaranteed that these documents can be provided when or before the food is delivered. In such cases, however, the name of the food, the indication of durability and the manufacturer, packer or seller’s name and address details must always appear on the outermost packaging in which that food is sold.

1.9.11

Intelligibility

To ensure clarity of labelling information under normal conditions of purchase, all of the labelling information should be easy to understand. This would normally mean that it is provided in the official language(s) of the country(ies) to which the foods are being exported, should also be clearly legible and indelible and marked in a conspicuous place so as to be clearly visible and not hidden, obscured or interrupted by other written or pictorial matter.

1.9.12

Field of vision

Certain information must be provided in the same field of vision at least once on the label, namely:

r r r

The legal name; The durability indication (or a signpost to it); and The quantity mark.

The same field of vision is understood to mean simultaneously readable under normal conditions of retail sale. It does not necessarily mean on the same face of the pack, but it does mean that the consumer must be able to read the information without having to keep turning the product in order to find it. So, for example, part of the side of a can and its top or bottom might well be in the same field of vision, but opposite sides of a can would not.

1.9.13

Nutrition labelling

Under Council Directive 90/496/EEC (European Union, 1990b) on nutrition labelling for foodstuffs, the provision of nutrition labelling is optional unless a nutrition or health claim is made about a food. So, for example, whilst the indication of a fish product’s content would not constitute a nutrition claim, statements such as ‘low saturates’ or ‘reduced salt’ would. When nutrition information is provided, either the ‘Group 1’ format or the ‘Group 2’ format as set out below, must be used. However, where a nutrition claim is made for sugars, saturates, fibre or sodium, the Group 2 format is mandatory.

Legal requirements for producers selling canned fish into Europe

Group 2

Group 1 Energy Protein Carbohydrate Fat

17

kJ and kcal g g g

Energy Protein Carbohydrate of which: Sugars Fat of which: Saturates Fibre Sodium

kJ and kcal g g g g g g g

The following nutrients may be added to a Group 1 or Group 2 declaration on a voluntary basis, but must be declared if a claim about them is made: Polyols Starch Monounsaturatesa Polyunsaturatesa Cholesterola Vitaminsb Mineralsb

g g g g mg mg/µg mg/µg

a

When one of these is declared, saturates must also be declared. Only listed vitamins and minerals may be declared, and they must be present in significant amounts. As a rule this means that at least 15% of the RDA should be supplied by 100 g/mL of the food or, for packages containing a single portion, by a package of the food. Vitamins and minerals which may be included in a nutrition declaration are listed in Directive 90/496/EEC.

b

Any nutrient not listed above may be declared only if a claim has been made about it and it is a component of a nutrient as defined. The energy value to be declared must be calculated using the following conversion factors: Carbohydrate (except polyols) Polyols Protein Fat Alcohol (ethanol) Organic acids

17 10 17 37 29 13

kJ/g kJ/g kJ/g kJ/g kJ/g kJ/g

4 kcal/g 2.4 kcal/g 4 kcal/g 9 kcal/g 7 kcal/g 3 kcal/g

The factors given above must be used to calculate the total energy value; they must not be determined by analysis. The energy contribution of nutrients with no listed conversion factors can be ignored, unless the statement of total energy becomes untrue or misleading. The declared value must be an average based either alone or in combination, on:

r r r

The manufacturer’s analysis of the food; A calculation from the actual average value of the ingredients used in the preparation of the food; and A calculation from generally established and accepted data such as McCance and Widdowson’s The Composition of Foodstuffs (Food Standards Agency, 2002).

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‘Average’ is defined as the figure which best represents the respective amounts of the nutrients which a given food contains, taking into account seasonal variability, and any other factors which may cause the actual amount to vary.

1.9.14

Claims, descriptions and marketing terms

Whilst falsely describing or providing misleading information about a food would be an offence under the EU General Food Law Regulation 178/2002, certain claims must not be made in the labelling or advertising of food except in accordance with specific conditions which are laid down. The controls are detailed and in some cases complex but, for example, they restrict the vitamins in which respect of which claims may be made to the following, subject to conditions set out in Table 1.2. Table 1.2 Vitamins for which claims may be made, subject to conditions. Vitamin A Vitamin D Vitamin E Vitamin C Thiamin Riboflavin

Niacin Vitamin B6 Folacin/Folic acid Vitamin B12 Biotin Pantothenic acid

Claims, which may be made in respect of minerals, are similarly controlled, as shown in Table 1.3. Table 1.3 Minerals for which claims may be made, subject to conditions. Calcium Phosphorus Iron

1.9.15

Magnesium Zinc Iodine

Health and nutrition claims

At the end of 2006, after many years of discussion, a Regulation (EC) No. 1924/2006 (European Union, 2006b) on nutrition and health claims was adopted. It comes into force at various dates extending up to and beyond 2010. The regulation applies to nutrition and health claims made in commercial communications, whether in the labelling, presentation or advertising of foods to be delivered as such to the final consumer. This would probably include product labels, print and broadcast media, statements made on the internet, posters, explanatory leaflets, in-store promotion and any commercial communication. The Regulation also applies to foods intended for supply to restaurants, hospital, schools, canteens and similar mass caterers. The principal types of claims that are controlled are:

r

Nutrition claims: Any claim which states, suggests or implies that a food has particular beneficial nutritional properties due to the energy (calorific value) it provides, provides at a reduced or

Legal requirements for producers selling canned fish into Europe

r r

19

increased rate or does not provide and/or the nutrients or other substances it contains, contains in reduced or increased proportions or does not contain, for example, ‘low salt’. Health claims: Any claim that states, suggests or implies that a relationship exists between a food category, a food or one of its constituents and health. ‘Low-salt foods can help to maintain a healthy cardiovascular system’. Reduction of disease risk claim: Any health claim that states, suggests or implies that the consumption of a food category, a food or one of its constituents, significantly reduces a risk factor in the development of a human disease. ‘Eating low-salt foods can help prevent high blood pressure, an important factor in maintaining a healthy cardiovascular system’.

Nutrition and health claims must not: (a) (b) (c) (d)

Be false, ambiguous or misleading; Give rise to doubt about the safety and/or the nutritional adequacy of other foods; Encourage or condone excess consumption of a food; State, suggest or imply that a balanced and varied diet cannot provide appropriate quantities of nutrients in general (derogations may be adopted); and (e) Refer to changes in bodily functions which could give rise to or exploit fear in the consumer, either textually or through pictorial, graphic or symbolic representations. By 19 January 2009, the Commission should have, but had not yet established, specific nutrient profiles, including exemptions, with which food or certain categories of food must comply in order to bear nutrition or health claims. The nutrient profiles will be based on scientific knowledge about diet and nutrition and their relation to health, and take into account:

r r r

The quantities of certain nutrients and other substances contained in the food, such as fat, saturated fatty acids, trans-fatty acids, sugars and salt/sodium; The role and importance of the food (or category of food) and the contribution to the diet of the population in general, or, as appropriate, of certain risk groups including children; and The overall nutritional composition of the food and the presence of nutrients that have been scientifically recognised as having an effect on health.

As a relaxation of these rules, however, nutrition claims referring to the reduction of fat, saturated fatty acids, trans-fatty acids, sugars and salt/sodium will be allowed without reference to a profile for the specific nutrient for which the claim is made, provided they comply with the conditions of the Regulation. Furthermore, where a single nutrient exceeds the nutrient profile a nutrient claim may be made provided that a statement about the specific nutrient appears in close proximity to, on the same side and with the same prominence as the claim. This statement must read as follows ‘High X content’, where ‘X’ is the out-of-profile nutrient. The use of nutrition and health claims is permitted only if:

r

The presence, absence or reduced content in a food or category of food of a nutrient, or other substance in respect of which the claim is made has been shown to have a beneficial nutritional or physiological effect, as established by generally accepted scientific evidence;

20

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r r

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Fish Canning Handbook

The nutrient or other substance for which the claim is made: – Is contained in the final product in a significant quantity (as defined in Community legislation), or where such rules do not exist, in a quantity that will produce the nutritional or physiological effect claimed as established by generally accepted scientific evidence; or – Is not present or is present in a reduced quantity that will produce the nutritional or physiological effect claimed as established by generally accepted scientific evidence; Where applicable, the nutrient or other substance for which the claim is made is in a form that is available to be used by the body; The quantity of the product that can reasonably be expected to be consumed provides a significant quantity of the nutrient or other substance to which the claim relates, as defined in Community legislation, or where such rules do not exist, a significant quantity that will produce the nutritional or physiological effect claimed as established by generally accepted scientific evidence; and It complies with the specific conditions laid down.

The use of nutrition and health claims is permitted only if the average consumer can be expected to understand the beneficial effects as expressed in the claim. Nutrition and health claims must refer to the food ready for consumption in accordance with the manufacturer’s instructions.

1.9.16

Specific conditions for nutrition claims

Nutrition claims are permitted only if they are listed in Table 1.4, in accordance with the conditions given.

1.9.17

Food assurance schemes

Assurance schemes are voluntary schemes which verify, through regular independent inspections, that certain stated standards of production are met, which can cover both the catching of fish and its processing. So, for example, the Marine Stewardship Council (MSC) has set an internationally recognised environmental standard for sustainable fishing based on 3 principles and 31 performance indicators. Only seafood from an MSC certified fishery can carry the blue MSC eco label. The standard is science-based and applies to wild-capture fisheries only – whatever their size, type or location – but does not apply to farmed fish. The complementary MSC Chain of Custody standard for seafood traceability makes sure that the MSC label is only displayed on seafood from an MSC-certified sustainable fishery.

1.10 LOT MARKING EC Directive 89/396 (European Union, 1989b) on indications or marks identifying the lot to which a foodstuff belongs requires a lot mark to appear on the packaging or on an attached label. Where

Legal requirements for producers selling canned fish into Europe Table 1.4

21

Permitted nutrition claims.

Nutrition claim (and any claim likely to have the same meaning for the consumer)

Conditions of use

Low energy

Product must not contain more than 40 kcal (170 kJ)/100 g for solids or more than 20 kcal (80 kJ)/100 mL for liquids. For table-top sweeteners the limit of 4 kcal (17 kJ)/portion, with equivalent sweetening properties to 6 g of sucrose (approximately 1 teaspoon of sucrose) applies.

Energy-reduced

Energy value is reduced by at least 30%, with an indication of the characteristic(s) which make(s) the food reduced in its total energy value.

Energy-free

Product must not contain more than 4 kcal (17 kJ)/100 mL. For table-top sweeteners the limit of 0.4 kcal (1.7 kJ/portion), with equivalent sweetening properties to 6 g of sucrose (approximately 1 teaspoon of sucrose) applies.

Low fat

Product must not contain more than 3 g of fat per 100 g for solids or 1.5 g of fat per 100 mL for liquids (1.8 g of fat per 100 mL for semi-skimmed milk).

Fat-free

Product must not contain more than 0.5 g of fat per 100 g or 100 mL. Claims expressed as ‘X% fat-free’ are prohibited.

Low-saturated fat

The sum of saturated fatty acids and trans-fatty acids in the product must not exceed 1.5 g per 100 g for solids or 0.75 g per 100 mL for liquids and in either case the sum of saturated fatty acids and trans-fatty acids must not provide more than 10% of energy.

Saturated fat-free

The sum of saturated fat and trans-fatty acids must not exceed 0.1 g of saturated fat per 100 g or 100 mL.

Low sugars

Product must not contain more than 5 g of sugars per 100 g for solids or 2.5 g of sugars per 100 mL for liquids.

Sugars-free

Product must not contain more than 0.5 g of sugars per 100 g or 100 mL.

With no added sugars

Product must not contain any added mono- or disaccharides or any other food used for its sweetening properties. If sugars are naturally present in the food, the statement ‘Contains naturally occurring sugars’ must appear on the label.

Low sodium/salt

Product must not contain more than 0.12 g of sodium, or the equivalent value for salt, per 100 g or per 100 mL. For waters, other than natural mineral waters, the level must not exceed 2 mg of sodium per 100 mL.

Very low sodium/salt

Product must not contain more than 0.04 g of sodium, or the equivalent value for salt, per 100 g or 100 mL. This claim must not be used for natural mineral waters and other waters.

Sodium-free or salt free

Product must not contain more than 0.005 g of sodium, or the equivalent value for salt, per 100 g.

Source of fibre

Product must contain at least 3 g of fibre per 100 g or at least 1.5 g of fibre per 100 kcal.

High fibre

Product must contain at least 6 g of fibre per 100 g or at least 3 g of fibre per 100 kcal.

Source of protein

At least 12% of the energy value of the food must be provided by protein.

High protein

At least 20% of the energy value of the food must be provided by protein. (Continued )

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Table 1.4

(Continued )

Nutrition claim (and any claim likely to have the same meaning for the consumer)

Conditions of use

Source of vitamin and/or mineral

Product must contain at least a significant amount as defined in the Annex to Directive 90/496/EEC (as a rule this means 15% of the RDA supplied by 100 g or 100 mL or per package if the package contains only a single portion).

High vitamin and/or mineral

Product must contain at least twice the value of ‘source of’ claim.

Contains (name of nutrient or other substance

No specific conditions laid down. Product must comply with the applicable provisions of the Regulation and in particular the ‘general conditions’. For vitamins and minerals the conditions of the claim ‘source of’ apply.

Increased (name of nutrient)

Product must comply with the conditions for the claim ‘source of’ and the increase in content is at least 30% compared to a similar product.

Reduced (name of nutrient)

Reduction in content must be at least 30% compared to a similar product, except for micronutrients, where a 10% difference in the reference values in Directive 90/496/EEC are acceptable, and for sodium, or the equivalent in salt, where a 25% difference is acceptable.

Light/lite

Product must comply with the conditions for use of the term ‘reduced’ and the claim must also be accompanied by an indication of the characteristic(s) which make(s) the food ‘light’ or ‘lite’.

Naturally/natural

Where a food naturally complies with the conditions laid down for use of a nutritional claim, the term ‘naturally/natural’ may be used as a prefix to the claim.

retail packs are enclosed in a wholesale pack, the lot mark should also appear on the outer container. Like other labelling information, it must be easily visible, clearly legible and indelible. The lot mark must be preceded by the letter ‘L’, except where it is clearly distinguishable from other labelling information. There is, however, an important exemption for foods which bear a date mark which consists, as a minimum, of a day and a month. Products described as best before end month are generally recognised as being able to benefit from this exemption.

1.11 FOOD CONTACT MATERIALS Regulation (EC) No. 1935/2004 (European Union, 2004e) on materials and articles intended to come into contact with food is generally termed the ‘Framework’ Directive on food contact materials. The regulation applies to materials and articles which are intended to be brought into contact with food and thus includes cans, glass jars and lids, as well as other equipment with which food may come into contact with during its processing. Although the Regulation provides for specific rules to be developed for particular groups of materials and articles, including glass and metals and alloys, specific measures have so far been agreed only for ceramics, plastics and regenerated cellulose and

Legal requirements for producers selling canned fish into Europe

23

the epoxy derivatives 2,2-bis(4-hydroxyphenyl) propane bis(2,3-epoxypropyl) ether (BADGE), bis(hydroxyphenyl) methane bis(2,3-epoxypropyl) ethers (BFDGE) and novolac glycidyl ethers (NOGE) (see below). Under the Framework Directive, the traceability of materials and articles must be established at all stages in order to facilitate control, the recall of defective products, consumer information and the attribution of responsibility. Fish canners must, therefore, have in place systems and procedures to identify the businesses from which materials and articles have been purchased and, where appropriate, the substances or products they have supplied. Generally, materials and articles must be manufactured in compliance with good manufacturing practice so that, under normal or foreseeable conditions of use, they do not transfer their constituents to food in quantities which could:

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Endanger human health; Bring about an unacceptable change in the composition of the food; or Bring about a deterioration in the organoleptic characteristics of the food.

1.11.1

Epoxy derivatives

Regulation (EC) No. 1895/2005 (European Union, 2005b) on the restriction of certain epoxy derivatives in materials and articles intended to come into contact with food applies to materials and articles, including active and intelligent food contact materials which are manufactured with or contain one or more of the following substances: BADGE, BFDGE and NOGE. Materials and articles covered by the scope of the Regulation are:

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Materials and articles made of any type of plastics; Materials and articles covered by surface coatings; and Adhesives.

The Regulation does not apply to containers or storage tanks having a capacity greater than 10 000 L or to pipelines belonging to or connected with them, covered by special coatings called ‘heavy duty coatings’. It is not permitted to manufacture, use for the handling of food in the course of a business, sell for the purpose of the handling of food, or import for the purpose of the handling of food, any material or article in contravention of the provisions in the EC Regulation. In particular, the use and/or presence of BFDGE and NOGE in the manufacturing of materials and articles is prohibited. Furthermore, materials and articles must not release the following substances into food in a quantity exceeding the following limits. The sum of BADGE, BADGE·H2 O and BADGE·2H2 O must not exceed 9 mg/kg in food or food simulants or 9 mg/6 dm2 for containers and similar articles with a capacity of less than 500 mL or more than 10 L, or sheet, film or other materials which cannot be filled or for which it is impracticable to estimate the surface area in contact with food. The sum of BADGE·HCl, BADGE ·2HCl and BADGE·H2 O·HCl must not exceed 1 mg/kg in food or in food simulants or 1 mg/6 dm2 for containers and similar articles with a capacity of less

24

Fish Canning Handbook

than 500 mL or more than 10 L, or sheet, film or other materials which cannot be filled or for which it is impracticable to estimate the surface area in contact with food. Migration testing must be carried out in accordance with the rules in EC Directive 82/711/EC (European Union, 1882) and Directive 2002/72/EC (European Union, 2002g) (as amended). At marketing stages before retail, materials and articles containing BADGE and its derivatives must be accompanied by a written declaration stating that they comply with the legislation. Appropriate documentation must be available to demonstrate such compliance. Finally, Council Directive 94/62/EC (European Union, 1994c) on packaging and packaging waste specifies that packaging should not be marketed if the combined levels of lead, cadmium, mercury and hexavalent chromium, either in the packaging or in any of its packaging components, exceed 100 ppm. By way of Commission Decision 2001/171/EC (European Union, 2002d) there is an exemption for recycled glass packaging, which may contain up to 200 ppm.

1.12 ADDITIVES The principal EC controls on additives are:

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European Parliament and Council Directive 94/36/EC (European Union, 1994a) on colours for use in foodstuffs (European Parliament and Council Directive, 1995); European Parliament and Council Directive 95/2/EC (European Union, 2002d) on food additives other than colours and sweeteners; and European Parliament and Council Directive 94/35/EC (European Union, 1994b) on sweeteners for use in foodstuffs.

All as amended. Each Directive was developed under Council Directive 89/107/EEC (European Union, 1989a) concerning food additives authorised for use in foodstuffs intended for human consumption. This is generally referred to as the ‘Framework Directive’ on food additives. It provides that additives may be used only if they perform a useful purpose, are safe and do not mislead the consumer. Fish, molluscs and crustaceans, as well as their preparations, but not including prepared meals containing these ingredients, must not contain added colours unless specifically provided for elsewhere in the Regulations, other than by carry over (whereby an additive is present in a compound food only having been carried over from one of its ingredients where the additive is permitted). Amongst the specific provisions are that E514 (Brown FK) is specifically permitted in kippers at up to 20 mg/kg and E160b (Annatto, Bixin and Norbixin) can be used in smoked fish at up to 10 mg/kg. Furthermore, fish paste and crustacean paste, pre-cooked or cooked crustaceans, salmon substitutes, surimi, fish roe and smoked fish may contain further permitted colours subject to specific maximum levels that apply to their use singly or in combination. Preservatives and certain other additives are specifically controlled in relevant products as shown in Table 1.5.

Legal requirements for producers selling canned fish into Europe

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Table 1.5

Permitted ‘other additives’ specifically controlled in named fishery products.

Number

Food additive

Maximum level of use

E251 E252

Potassium nitrate Sodium nitrate in pickled herring and sprat

500 mg/kg (expressed as sodium nitrite)

E315 E316

Erythorbic acid Sodium erythorbate in preserved and semi-preserved fish products

1500 mg/kg (expressed as erythorbic acid)

E338

Phosphates (individually or in combination) in fish and crustacean pastes

5 g/kg (expressed as P2 O5 )

Canned crustacean products

Up to 1 g/kg

Calcium disodium ethylene diamine tetra-acetate (calcium disodium EDTA) may be added to canned and bottled crustacean, mollusc and fish

At 75 mg/kg

E339 E340 E341 E343 E450 E451 E452 E385

Table 1.6

Permitted sweeteners specifically controlled in named fishery products.

Number

Sweetener

Maximum usable dose

E954 E955 E962 E951 E950

Saccharin and its sodium, potassium and calcium salts Sucralose Salt of aspartame–acesulfame Aspartame Acesulfame K

160 mg/kg 120 mg/kg 200 mg/kg 300 mg/kg 200 mg/kg

Finally, the following sweeteners are permitted in sweet–sour preserves and semi-preserves of fish and marinades of fish, crustaceans and molluscs, as shown in Table 1.6.

1.13 FLAVOURINGS Flavourings are not currently controlled by positive lists of the type adopted for most other classes of food additives. However, flavouring substances authorised for use in or on foodstuffs have been listed by the European Commission in a register of about 2700 substances adopted as Commission Decision 1999/217/EC (European Union, 1999). The registered substances are being evaluated in turn by the European Food Safety Authority (the expert body which advises the European Commission on risk assessment) according to a programme which is still under way. Meanwhile, Regulation (EC) No. 2065/2003 (European Union, 2003c) of 10 November 2003 on smoke flavourings lays down a Community procedure for the evaluation and authorisation of primary smoke condensates and primary tar fractions for use as such in or on foods or in the production of derived smoke flavourings for use in or on foods.

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Fish Canning Handbook

The Regulation also lays down the Community procedure for the establishment of a list of primary smoke condensates and primary tar fractions authorised to the exclusion of all others in the Community and their conditions of use in or on foodstuffs.

1.14 CONTAMINANTS Council Regulation (EEC) No. 315/93 (European Union, 1993) which lays down Community procedures for contaminants in food defines contaminant as: Any substance not intentionally added to food, which is present in such food as a result of the production (including operations carried out in crop husbandry, animal husbandry and veterinary medicine), manufacture, processing, preparation, treatment, packing, packaging, transport or holding of such food, or as a result of environmental contamination. Extraneous matter, such as insect fragments, and animal hair, is not covered by this definition. The regulation prohibits food containing a contaminant in an amount which is unacceptable from the public health viewpoint, and in particular at a toxicological level, from being placed on the market. Furthermore, contaminant levels must be kept as low as can reasonably be achieved by following good practices at all stages of production, manufacturing, processing, preparation, treatment, packing, packaging, transport and holding of food. In any event, the presence in food of any contaminant in sufficiently high level would mean that the food failed to meet the food safety requirements set out in Regulation (EC) No. 178/2002. Nevertheless, in order further to protect public health, a number of regulations setting maximum levels for specific contaminants have also been established via Commission Regulation (EC) No. 1881/2006 (European Union, 2007b) as follows:

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Nitrites: Commission Regulation (EC) No. 563/2002 (European Union, 2002f); Mycotoxins: Commission Regulations (EC) No. 257/2002 (European Union, 2002c) and 472/2002 (European Union, 2002e); Dioxins and dioxin-like PCBs: Commission Regulation (EC) No. 1883/2006 (European Union, 2006a); and Lead, cadmium, mercury and 3-MCPD: EC Commission Regulation (EC) No. 221/2002 (European Union, 2002b).

Table 1.7 sets out statutory maximum levels relevant to canned fish for each specific contaminant.

1.15

PESTICIDES

Council Directive 91/414/EEC (European Union, 1991) on plant protection products provides for the establishment of a list of plant protection products that in due course will be permitted to the exclusion of all others. In each case, the substances will have been evaluated by the European Food Safety Authority, and found to be safe in use from both a public health and an environmental viewpoint. Regulation (EC) No. 396/2005 (European Union, 2005a) on maximum residue levels (MRLs) of pesticides in or on food and feed of plant and animal origin put in place a new regulatory regime at EU level from September 2008.

Legal requirements for producers selling canned fish into Europe Table 1.7

27

Maximum levels of contaminants specifically permitted in named fishery products.

Product

Contaminant

Maximum level

Muscle meat of fish (except those listed below)

Lead

0.2 mg/kg (wet weight)

Muscle meat of bonito, common-to-banded sea bream, eel, grey mullet, grunt, horse mackerel or scad, sardine, sardinox, spotted sea bass, tuna, wedge sole

Lead

0.4 mg/kg

Crustaceans excluding brown meat of crab

Lead

0.5 mg/kg

Bivalve molluscs

Lead

1.5 mg/kg

Muscle meat of fish (except those listed below)

Cadmium

0.05 mg/kg

Muscle meat of bonito, common-to-banded sea bream, eel, European anchovy, grey mullet, horse mackerel or scad, louvar or luvar, sardine, sardinox, tuna, wedge sole

Cadmium

0.1 mg/kg

Crustaceans, excluding brown meat of crab and excluding head and thorax meat of lobster and similar large crustaceans

Cadmium

0.5 mg/kg

Bivalve molluscs

Cadmium

1 mg/kg

Fishery products except those listed below

Mercury

0.5 mg/kg

Anglerfish, Atlantic catfish, bass, blue ling, bonito, eel, emperor or orange ruffey, grenadier, halibut, marlin, pike, plain bonito, Portuguese dogfish, rays, redfish, sail fish, scabbard fish, shark (all species), snake mackerel or butter fish, sturgeon, swordfish, tuna

Cadmium

1.0 mg/kg

Muscle meat of fish and fishery products and products thereof

Dioxin (PCDD + PCDF)

4 pg (WHO-PCDD-F-TEQ-G fresh weight)

Canned food other than beverages and products for infants and young children

Tin (inorganic)

200 mg/kg (wet weight)

Once fully developed, a series of annexes will set out the following: Annex I

Products or groups of products for which no specific MRLs have been established, unless the active substance is listed as exempt at Annex IV. In these cases typically a default MRL of 0.01 mg/kg applies; Annex II EC definitive MRLs; Annex III EC temporary MRLs; and Annex IV Exempt active substances. Whilst there are no MRLs set for fish and similar products, MRLs for certain other ingredients of prepared fish products would need to comply with the relevant MRLs.

1.16 VETERINARY MEDICINAL PRODUCTS Council Regulation (EEC) No. 2377/90 (European Union, 1990a) lays down a Community procedure for the establishment of residue limits of veterinary medicinal products in foodstuffs of animal origin.

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Fish Canning Handbook

The Regulations bans the sale for human consumption of any animal product which contains an unauthorised substance or an authorised substance exceeding the relevant MRL. Residues of many pharmacologically active substances are controlled in fish, normally by specifying, in each case, the pharmacologically active substance, marker residue, animal species, MRLs, target tissues and any other provisions.

1.17

WEIGHTS AND MEASURES

Controls on canned fish products are subject to Council Directive 76/211/EEC (European Union, 1976), sometimes known as the Solids Directive. This is intended to harmonise quantity control procedures across Member States by allowing packages that meet certain standards to be marked with an ‘e’ mark and for those packages to be allowed free access for metrological control purposes across all other Member States. The Directive requires that Member States do not, on metrological or related labelling grounds, refuse access to packages which satisfy their requirements. Member States must also establish systems permitting the e-marking of packages and for enforcement. Packages have to be made up in such a way that they meet the following requirements:

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The actual contents, i.e. the weight of product which in fact contains, shall not be less, on average, than the nominal quantity, i.e. the quantity of product which the pre-package is deemed to contain; The proportion of pre-packages having a negative error (the quantity by which the actual contents of the pre-package are less than the nominal quantity) greater than the tolerable negative error laid down for that size of pack shall be sufficiently small for batches of pre-packages to satisfy the requirements of the reference test specified in the Directive; and No pre-package shall have a negative error greater than twice the tolerable negative error laid down.

All pre-packages made up in accordance with this Directive must then be marked indelibly, easily legibly and visibly with:

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‘The nominal quantity (weight or volume)’. ‘A mark or inscription enabling the competent departments to identify the packer or the person arranging for the packing to be done or the importer established in the Community’. ‘A small “e”, at least 3 mm high, placed in the same field of vision as the indication of the nominal quantity. . .’.

For packages produced in the European Economic Area (EEA), i.e. EU plus Iceland, Norway and Liechtenstein, the packer is responsible for meeting this requirement. For packages produced outside the EEA, the first importer based in the EEA is responsible for meeting this requirement. Domestic legislation may specify whether the company or individual employee is held responsible. In the case of imports from non-EEC countries, the importer may, instead of measuring and checking, provide evidence that he is in possession of all the necessary guarantees enabling him to assume responsibility. Some of the acceptable guarantees include:

Legal requirements for producers selling canned fish into Europe

r r r r

29

Evidence from a competent department in a Member State; Evidence from an EEA accepted competent department in the exporting country; Records of checks carried out by a competent sub-contractor at the place of first entry into the EEA; and To obtain records from the packer and to carry out checks to verify the data contained in them.

1.18 WARNING This description of EU legislation was current at the time of drafting (November 2008). Legislation is subject to regular development or amendment. Readers are therefore encouraged always to consult the most up-to-date legislation.

REFERENCES European Commission (2006) Guidance Document on certain key questions related to import requirements and the new rules on food hygiene and on official food controls. European Court of Justice (1979) Judgment of the Court of 20 February 1979. Rewe-Zentral AG v Bundesmonopolverwaltung f¨ur Branntwein. Reference for a preliminary ruling: Hessisches Finanzgericht – Germany. Measures having an effect equivalent to quantitative restrictions. Case 120/78. European Union (1976) Council Directive 76/211/EEC of 20 January 1976 on the approximation of the laws of the Member States relating to the making-up by weight or by volume of certain pre-packaged products. Official Journal of the EU, L46, 1–11. European Union (1981) Council Regulation (EEC) No. 3796/81 of 29 December 1981 on the common organization of the market in fishery products. Official Journal of the EU, L379, 1–26. European Union (1882) Council Directive 82/711/EEC of 18 October 1982 laying down the basic rules necessary for testing migration of the constituents of plastic materials and articles intended to come into contact with foodstuffs. Official Journal of the EU, L297, 26–30. European Union (1987) Council Regulation (EEC) No. 2658/87 of 23 July 1987 on the tariff and statistical nomenclature and on the Common Customs Tariff. Official Journal of the EU, L256, 1–675. European Union (1989a) Council Directive 89/107/EEC of 21 December 1988 on the approximation of the laws of the Member States concerning food additives authorized for use in foodstuffs intended for human consumption. Official Journal of the EU, L40, 27–33. European Union (1989b) Council Directive 89/396/EEC of 14 June 1989 on indications or marks identifying the lot to which a foodstuff belongs. Official Journal of the EU, L186, 21–22. European Union (1989c) Council Regulation (EEC) No. 2136/89 of 21 June 1989 laying down common marketing standards for preserved sardines. Official Journal of the EU, L212, 79–81. European Union (1990a) Council Regulation (EEC) No. 2377/90 of 26 June 1990 laying down a Community procedure for the establishment of maximum residue limits of veterinary medicinal products in foodstuffs of animal origin. Official Journal of the EU, L224, 1–8. European Union (1990b) Council Directive 90/496/EEC of 24 September 1990 on nutrition labelling for foodstuffs. Official Journal of the EU, L276, 40–44. European Union (1991) Council Directive 91/414/EEC of 15 July 1991 concerning the placing of plant protection products on the market. Official Journal of the EU, L230, 1–32. European Union (1992) Council Regulation (EEC) No. 1536/92 of 9 June 1992 laying down common marketing standards for preserved tuna and bonito. Official Journal of the EU, L163, 1–4. European Union (1993) Council Regulation (EEC) No. 315/93 of 8 February 1993 laying down Community procedures for contaminants in food. Official Journal of the EU, L37, 1–3. European Union (1994a) European Parliament and Council Directive 94/36/EC of 30 June 1994 on colours for use in foodstuffs. Official Journal of the EU, L237, 13–29.

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European Union (1994b) European Parliament and Council Directive 94/35/EC of 30 June 1994 on sweeteners for use in foodstuffs. Official Journal of the EU, L237, 3–12. European Union (1994c) European Parliament and Council Directive 94/62/EC of 20 December 1994 on packaging and packaging waste. Official Journal of the EU, L365, 10–23. European Union (1995) European Parliament and Council Directive 95/2/EC of 20 February 1995 on food additives other than colours and sweeteners. Official Journal of the EU, L61, 1–40. European Union (1999) Commission Decision 1999/217/EC of 23 February 1999 adopting a register of flavouring substances used in or on foodstuffs drawn up in application of Regulation (EC) No. 2232/96 of the European Parliament and of the Council of 28 October 1996 (notified under number C(1999) 399). Official Journal of the EU, L84, 1–137. European Union (2000a) Council Regulation (EC) No. 104/2000 of 17 December 1999 on the common organisation of the markets in fishery and aquaculture products. Official Journal of the EU, L17, 22–52. European Union (2000b) Directive 2000/13/EC of the European Parliament and of the Council of 20 March 2000 on the approximation of the laws of the Member States relating to the labelling, presentation and advertising of foodstuffs. Official Journal of the EU, L109, 29–42. European Union (2001a) European Union Commission Regulation (EC) No. 2065/2001 of 22 October 2001 laying down detailed rules for the application of Council Regulation (EC) No. 104/2000 as regards informing consumers about fishery and aquaculture products. Official Journal of the EU, L278, 6–8. European Union (2001b) Commission Decision 881/2001 drawing up a list of border inspection posts agreed for veterinary checks on animals and animal products from third countries and updating the detailed rules concerning the checks to be carried out by the experts of the Commission. Official Journal of the EU, L326, 44–62. European Union (2002a) Council Regulation (EC) No. 178/2002 of the European Parliament and of the Council of 28 January 2002 laying down the general principles and requirements of food law, establishing the European Food Safety Authority and laying down procedures in matters of food safety. Official Journal of the EU, L31, 1–24. European Union (2002b) Commission Regulation (EC) No. 221/2002 of 6 February 2002 amending Regulation (EC) No. 466/2001 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the EU, L37, 4–6. European Union (2002c) Commission Regulation (EC) No. 257/2002 of 12 February 2002 amending Regulation (EC) No. 194/97 setting maximum levels for certain contaminants in foodstuffs and Regulation (EC) No. 466/2001 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the EU, L41, 12–15. European Union (2002d) Commission Decision 2001/171/EC of 19 February 2001 establishing the conditions for a derogation for glass packaging in relation to the heavy metal concentration levels established in Directive 94/62/EC on packaging and packaging waste. Official Journal of the EU, L62, 20–21. European Union (2002e) Commission Regulation (EC) No. 472/2002 of 12 March 2002 amending Regulation (EC) No. 466/2001 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the EU, L75, 18–20. European Union (2002f) Commission Regulation (EC) No. 563/2002 of 2 April 2002 amending Regulation (EC) No. 466/2001 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the EU, L86, 5–6. European Union (2002g) Commission Directive 2002/72/EC of 6 August 2002 relating to plastic materials and articles intended to come into contact with foodstuffs. Official Journal of the EU, L220, 18–58. European Union (2003a) Commission Regulation (EC) No. 89/2003 of 17 January 2003 laying down to what extent applications for issue of export licences submitted during January 2003 for beef products which may benefit from special import treatment in a third country may be accepted. Official Journal of the EU, L13, 17. European Union (2003b) Commission Regulation (EC) No. 1181/2003 of 2 July 2003 amending Council Regulation (EEC) No. 2136/89 laying down common marketing standards for preserved sardine. Official Journal of the EU, L165, 17–18. European Union (2003c) Regulation (EC) No. 2065/2003 of the European Parliament and of the Council of 10 November 2003 on smoke flavourings used or intended for use in or on foods. Official Journal of the EU, L309, 1–8. European Union (2004a) Regulation (EC) No. 852/2004 of the European Parliament and of the Council of 29 April 2004 on the hygiene of foodstuffs. Official Journal of the EU, L139, 1–54. European Union (2004b) Regulation (EC) No. 853/2004 of the European Parliament and of the Council of 29 April 2004 laying down specific hygiene rules for food of animal origin. Official Journal of the EU, L139, 55–205. European Union (2004c) Regulation (EC) No. 854/2004 laying down specific rules for the organisation of official controls on products of animal origin intended for human consumption. Official Journal of the EU, L139, 206–320.

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European Union (2004d) Regulation (EC) No. 882/2004 of the European Parliament and of the Council of 29 April 2004 on official controls performed to ensure the verification of compliance with feed and food law, animal health and animal welfare rules. Official Journal of the EU, L165, 1–141. European Union (2004e) Regulation (EC) No. 1935/2004 of the European Parliament and of the Council of 27 October 2004 on materials and articles intended to come into contact with food and repealing Directives 80/590/EEC and 89/109/EEC. Official Journal of the EU, L338, 4–17. European Union (2005a) Regulation (EC) No. 396/2005 of the European Parliament and of the Council of 23 February 2005 on maximum residue levels of pesticides in or on food and feed of plant and animal origin and amending Council Directive 91/414/EEC. Official Journal of the EU, L70, 1–16. European Union (2005b) Commission Regulation (EC) No. 1895/2005 of 18 November 2005 on the restriction of use of certain epoxy derivatives in materials and articles intended to come into contact with food. Official Journal of the EU, L302, 28–32. European Union (2005c) Commission Regulation (EC) No. 2073/2005 of 15 November 2005 on microbiological criteria for foodstuffs. Official Journal of the EU, L338, 1–26. European Union (2006a) Commission Regulation (EC) No. 1883/2006 of 19 December 2006 laying down methods of sampling and analysis for the official control of levels of dioxins and dioxin-like PCBs in certain foodstuffs. Official Journal of the EU, L364, 32–43. European Union (2006b) Regulation (EC) No. 1924/2006 of the European Parliament and of the Council of 20 December 2006 on nutrition and health claims made on foods. Official Journal of the EU, L404, 9–25. European Union (2007a) Commission Decision 2007/275/EC concerning lists of animals and products to be subject to controls at border inspection posts under Council Directives 91/496/EEC and 97/78/EC. Official Journal of the EU, L116, 9–33. European Union (2007b) Commission Regulation (EC) No. 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the EU, L364, 5–24. Food Standards Agency/Institute of Food Research/Royal Society of Chemistry (2002) McCance and Widdowson’s: The Composition of Foods, 6th summary edition. International Organization for Standardization (2006) Codes for the representation of names of countries and their subdivisions. Part 1 Country codes. ISO 3166 part 1, Geneva. SLIM (1996) Simplification of the Internal Market (SLIM) programme. For further information on how SLIM works, see Commission Communication on Simpler Legislation for the Internal Market (SLIM) (COM(1996)204). This also provides details on the work of SLIM teams during phase 1. WELMEC (2006) Guidance for the Verification of Drained Weight, Drained Washed Weight and Deglazed Weight and Extent of Filling of Rigid Food Containers.

2

Legal requirements for producers selling canned fish into North America

Kenneth Lum

2.1 INTRODUCTION This chapter describes current legislation, including statutory (legal) and regulatory requirements for canned fish offered for sale in North America, primarily in the United States and Canada. In the United States and Canada, laws are promulgated to protect human health. The laws are enforced by regulations that provide the underpinning requirements for the production of safe food products. Laws and regulations not only focus on requirements related to safe food production but also address issues related to labelling and economic integrity. It is important to note that the legislative process is not static, with new and amended rules and regulations continuously being considered and implemented as legislators take into account the most up-to-date scientific information and legal requirements. Legislation is becoming increasingly complex due to the globalisation of trade, with the need to create rules and regulations that can be effectively implemented and complied with by both domestic and foreign producers. Producers supplying canned fish products to the North American market must be fully aware of these requirements to avoid production of non-compliant food, as well as disruption of trade. While this chapter provides an overview of current legislation applicable to canned fish sold in North America, laws and regulations are frequently changed. Therefore, it is very important for companies or individuals selling food products to North American markets to stay current with legal and regulatory requirements. For this purpose, references to the legislation discussed in this chapter are presented in footnotes that identify the internet sites (URLs) where updates are readily accessible.

2.2 CANNED FISH DESCRIPTION Most canned fish products are composed of ingredients that result in finished product with pH above 4.6 and a water activity greater than 0.85. These characteristics result in canned fish products being considered ‘low-acid canned foods’, or LACF. The legal and regulatory requirements intended to ensure the safe production of low-acid canned fish products consider target organisms that must be controlled to produce a commercially sterile, shelf stable product.

2.2.1

Definitions for commercial sterility

In Canada as defined by Canadian Food Inspection Agency (CFIA), ‘commercially sterile’ means the condition obtained in a canned fish product which has been processed by the application of heat, alone or in combination with other treatments, to render the food free from viable forms of microorganisms, including spores, capable of growing in the foods at temperatures at which the food is normally designed to be held during storage and distribution.

Legal requirements for producers selling canned fish into Europe

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Such a process is designed to result in the reduction of the reference organism, Clostridium botulinum, by 12 log (12D concept). This value may not ensure the destruction of all spoilage organisms. It is the processor’s responsibility to determine which critical factors will be used to ensure destruction of the pathogen C. botulinum as well as spoilage organisms. In the United States as defined by the U.S. Food and Drug Administration (FDA), ‘commercial sterility’ of thermally processed food means the condition achieved: (i) By the application of heat which renders the food free of: (a) Microorganisms capable of reproducing in the food under normal non-refrigerated conditions of storage and distribution; and (b) Viable microorganisms (including spores) of public health significance; or (ii) By the control of water activity and the application of heat, which renders the food free of microorganisms capable of reproducing in the food under normal non-refrigerated conditions of storage and distribution. As noted in the definitions for ‘commercially sterile’, the food safety objective for canned fish regulations is to ensure that pathogens of public health significance, particularly C. botulinum, are controlled. This objective is achieved not only by rendering the product free of pathogens but also by preventing re-entry of pathogens during subsequent handling of canned fish products. Due to the severe nature of food poisoning caused by C. botulinum toxin, requirements for the safe production of canned fish are of paramount importance.

2.3

WHY ARE REGULATIONS NECESSARY?

Three important reasons for implementing regulations for canned fish products are that they provide: 1. A roadmap to food safety: Laws and regulations provide a systematic path for processors to follow that will lead to the production of safe and legal canned fish products. Elements of the laws and regulations are directed at critical areas of production that must be controlled. 2. Procedural guidance for the processor: Regulations describe in detail the requirements that processors must follow to ensure the safe and legal production of canned fish. The regulatory requirements describe equipment qualifications and procedural steps, with associated monitoring and recordkeeping necessary for verification of compliance. 3. A template for inspection: The regulations provide inspectors with the specific criteria to evaluate processor performance, as necessary to determine compliance and ensure public protection and safety.

2.4 LEGAL REQUIREMENTS AND FOOD SAFETY The production of safe LACF relies primarily on two elements: 1. Ensuring the hermetic seal and integrity of the container from production through consumption; and 2. Application of an adequate process (usually a thermal process or cook) that provides commercial sterility.

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It follows that laws and regulations promulgated to address LACF safety provide manufacturing requirements intended to ensure good container integrity, as well as specifying equipment installations and procedures required to deliver an adequate thermal process to each container of product. The production of safe canned fish products is the primary responsibility of the producing company. Inspection and enforcement of regulations required to ensure the safe production of canned fish are the responsibility of federal, provincial and local regulatory authorities, as well as importers.

2.5 REGULATORY SYSTEMS IN CANADA AND THE UNITED STATES The legislative process is similar in Canada and the United States. The legal bases for regulations are statutory provisions, or laws, that are usually elaborated as acts. The primary laws that include the legal requirements for canned fish in Canada and the United States are listed below: Canada:

r r r

Food and Drugs Act Fish Inspection Act Consumer Packaging and Labelling Act

United States:

r r r

Food, Drug and Cosmetic (FDC) Act ‘Bioterrorism Act’ Fair Packaging and Labelling Act (FPLA)

Regulations are the requirements that support provisions of the law as authorised by the enabling Act. A regulation is a form of secondary legislation which is used to implement provisions of the applicable law. Canned fish producers must be aware of the regulations in the countries of final destination and consumption. It should also be noted that there might be provincial or state requirements that products may need to comply with, and suppliers should be aware of any local requirements that may be more stringent than the federal regulations. The remainder of this chapter provides a description and overview of the federal laws and regulations applicable to canned fish intended for the Canadian and U.S. markets.

2.6 CANADIAN REQUIREMENTS 2.6.1

Public policy, inspection and enforcement agencies

Health Canada Health Canada utilises a transparent risk assessment strategy to develop food safety-related policies. This approach includes a scientific risk assessment of both the severity and probability of food safety hazards resulting from regulated activities. Effectiveness of Health Canada’s risk assessment strategy for policy development is measured by the agency’s surveillance of food-borne illness outbreaks. The surveillance data enable Health Canada to evaluate the effectiveness of their riskbased food safety control strategies. Health Canada’s activities are assessed by the Minister of Health

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to ensure that the agency’s policies are effective. It should be noted that the Minister of Health also maintains oversight of some statutory provisions that relate to public health, safety or nutrition. Health Canada is also responsible for developing policy that supports laws and regulations related to nutritional quality of food products and consumer protection.

Canadian Food Inspection Agency The CFIA is the federal regulatory agency responsible for enforcement of food laws and regulations, including regulations that are applicable to both domestic producers and importers of canned fish products. Prior to 1997, most regulation of fish products was under the auspices of the Department of Fisheries and Oceans. However, in 1997 the CFIA was created and currently enforces 34 regulations under the authority of 13 federal acts/laws. With regard to canned fish specifically, CFIA would enforce applicable food provisions of the Food and Drugs Act, the Fish Inspection Act, and the Consumer Packaging and Labelling Act. Enforcement authority includes the agency’s right and responsibility for:

r r r

Inspection of food facilities Compliance determinations Hold or quarantine of products when necessary to protect public health

2.6.2 Laws and regulations in Canada The Canadian system for the regulation of food safety and nutrition is structured in a flexible and progressive manner that enables responsible federal agencies to promulgate laws and regulations that consider advancements in food science, novel food-processing technologies, international trade policies and consumer expectations. The legal and regulatory requirements in Canada emphasise protection of consumer health, science-based policy and collaboration of food producers, importers and regulators to ensure the safety of the food supply.

Food and Drugs Act 1 The Food and Drugs Act is the principal federal legislation covering food safety, and it prohibits the manufacture or sale of all dangerous or adulterated food products anywhere in Canada. The Act derives its authority from criminal law and is supplemented by regulations designed to ensure food safety and nutritional quality. Canada also has an extensive local-level regulatory system, which provides for provincial oversight and responsibility for implementing legislation to protect public health and to authorise inspection and compliance for applicable regulations.

Fish Inspection Act 2 The Fish Inspection Act (FIA) includes the laws and requirements that are most applicable for canned fish producers. The FIA, which updated on 2008/02/11, consists of 17 sections, as follows: 1 2

Food and Drugs Act: http://laws.justice.gc.ca/en/ShowTdm/cs/F-27///en. Fish Inspection Act: http://laws.justice.gc.ca/en/F-12.

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Title Section 1: Provides for citation as the Fish Inspection Act Interpretation Section 2: Definitions of terms used in and for the FIA Part I: Fish and fish containers Section 3: Authorises the Governor in Council to make regulation necessary to implement, inspect and enforce provisions of the FIA. The requirements for imported foods contained in Section 3 ensure that imported canned fish products produced in facilities using appropriate equipment and operating under sanitary conditions. Section 4: Describes the inspector’s authority to inspect and sample product. Section 5: Repealed Section 6: Grants inspectors the right to administer oaths and take and receive affidavits, declarations and solemn affirmations. Section 7: Authorises inspector to detain or seize product if there is reasonable grounds to conclude the product does not comply with the FIA or supporting regulation. Requires anyone convicted of offences against Part I requirements to forfeit the non-compliant fish or container(s). Section 8: The inspector or a constable may arrest without warrant any individual committing an offence against Part I. Section 9: Makes unlawful destruction or alteration of any documents related to compliance with Part I. Section 10: No person shall import, export, sell for export or have in his possession for export any fish intended for human consumption that is tainted, decomposed or unwholesome. Section 11: Repealed Part II: Marine plants Sections 12–15 have not been summarised, as they are not applicable to the subject matter of this chapter. Part III: General Section 16: Treats inter-provincial shipments as imports and exports. Section 17.1: Grants the President of the CFIA right to designate inspectors to uphold requirements of the FIA. This section provides procedure for designating and certificating inspectors. Section 17.2: Establishes statutory limitation for prosecution as two years after the minister becomes aware of the alleged offence, and provides for evidentiary documentation certifying the day the Minister became aware of the subject of the prosecution. Section 18: Establishes location of the offence for the purpose of prosecution as the place where the offence was actually committed, the place where it was first discovered by an inspector or the place where the defendant resides or is found.

2.6.3 Canadian regulations C.R.C., c. 8023 – Fish Inspection Regulations (FIR): Cited as the Consolidated Regulations of Canada (C.R.C), c. 802, the FIR cover inspections of processed fish and processing 3

Fish Inspection Regulation: http://laws.justice.gc.ca/en/showtdm/cr/C.R.C.-c.802.

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facilities. Following the title and definitions, the FIR regulation is divided into the following nine parts: Part I: Part II: Part III: Part IV: Part V: Part VI: Part VII: Part VIII: Part IX: Schedule I: Schedule II:

General Labelling Code marking Canned fish Fresh or frozen fish Pickled, spiced and marinated fish Bloaters and bloater fillets Salted fish Dried squid Establishment construction and equipment requirements Establishment sanitation requirements

Parts I–IV and Schedules I and II are further discussed in this chapter, as they apply to canned fish.

Part I: General Part I of the FIR describes the scope and application of the regulations. This includes a description of applicable fish products and containers covered by the regulation. It stipulates that all fish and containers are subject to inspection and sampling and that inspectors shall be granted access to fish and containers subject to inspection or re-inspection.

2.6.4

Key prohibitions in Part I that apply to canned fish

No person shall import, export or process for export or attempt to import, export or process for export:

r

Any fish that is tainted, decomposed or unwholesome or otherwise fails to meet the requirements of these regulations; or

No person shall import into Canada or attempt to import into Canada any fish unless:

r r r r r

The identity of the establishment at which the fish is packed and the day, month and year of packing are legibly marked on one end of the carton or case in which the containers of fish are shipped; In the case of high-risk products, a list indicating the establishment and the number of containers for each production code is provided to an inspector on request; Each container has a label on which the name of the country of origin is clearly identified; That person is the holder of an import license; and Written notification of each shipment of fish to be imported or that is imported is provided to an inspector either prior to the importation or within 48 hours following the importation. Detailed requirements for the notification are listed in the regulation.

No person shall move or attempt to move fish that has been imported into Canada from the place indicated in the notification unless:

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They have the proper import license; An inspector determines the product meets legal requirements; or The product does not require sampling.

No person shall import into Canada or attempt to import into Canada any canned fish unless:

r

The cans are embossed or otherwise permanently marked in a code that identifies the name of the establishment and day, month and year of processing.

2.6.5

General requirements for importers

Import licensing requirements Importers must apply for and obtain an import license annually. There are three types of import licenses that may be applied for: 1. Basic Import License: Import requirement compliance is primarily the responsibility of the regulatory agency – CFIA; 2. Shared Quality Management Program Import (QMPI) License: Responsibility for import requirement compliance is shared between the importer and CFIA; and 3. Enhanced QMPI License: Import requirement compliance is primarily the responsibility of the importer. An application fee is assessed on the basis of the type of import license applied for – either Basic License or QMPI License. Application and inspection fees are higher for importers with Basic licenses due to the greater effort and resources required of the regulatory agency to assure compliance. Likewise, fees are higher for Shared QMPI than for Enhanced QMPI license holders. The FIR include a detailed description of requirements for QMPI license holders that cover facility identification and contacts, a description of sample evaluation procedures, label reviews, corrective actions, trace forward requirements and programme review elements. The FIR describes conditions under which the President of the Agency may suspend, revoke or refuse an import license to the applicant, as well as the procedure an importer may exercise to gain reinstatement or acceptance of the import license application.

Specific canned fish requirements for imports An importer of canned fish shall maintain, at an address in Canada and for not less than three years, a record in English or French of: 1. The name, address and telephone number of the process authority who developed the thermal process used; 2. The container type, size and specifications, style of pack, species packed and if the thermal process utilised has not been published in scientific literature recognised by the Minister, the sterilising value (F 0 ) of the thermal process; and 3. A statement in writing signed by the representative of the process authority that attests that the thermal process results in the production of commercially sterile and safe fish products.

Import inspection Imports are subject to random inspection, using criteria in Table 2.1. Where a fish product is imported into Canada, and that fish product manufactured by that producer has not been imported

Legal requirements for producers selling canned fish into Europe Table 2.1

Inspection items.

Item

Type of Inspection

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28.

Sensory evaluation Net content determination Label evaluation Container integrity evaluation Fish content of battered or breaded products Histamine Escherichia coli Faecal coliforms Listeria monocytogenes Salmonella species Standard plate count Staphylococcus aureus Vibrio species Electrophoresis species identification Food additives Sodium and potassium Heavy metals, other than mercury Mercury Moisture content Pesticides and polychlorinated biphenyls Salt content Marine toxins Drug residues pH Water activity Sterility Quality indices Tuna colour

39

into Canada within the previous two years, that importation shall undergo every type of inspection listed in Table 2.1 applicable to that type of fish product. QMP Importers must use laboratories recognised by the President of the Agency as being competent to conduct those services or has been accredited by the Standards Council of Canada.

Detained product The regulation includes procedures for identifying, marking and controlling the movement of any product being detained. Procedures for notifying the importer and release of products demonstrating compliance are also included in the regulation. Requirements and qualifications for detained entries to be re-inspected are provided by the regulation. Determination of final disposition of detained or re-inspected products is in the purview of the President of the Agency.

2.6.6

General requirements for exporters

Note: It is important to note that the Canadian definition for ‘export’ as it applies to the FIR differs significantly from the U.S. definition for export. In Canada, exports are products that are shipped internationally as well as inter-provincially, while in the United States, exports are products that are shipped internationally.

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Establishment registration No person shall export fish, process fish for export or store fish for export unless the processing or storing of that fish is carried out in a registered establishment. The application for establishment registration includes identification and location of the processing facility, product and process details and a description of the facility QMP that includes prerequisite programmes, a regulatory action point plan, hazard analysis and critical control points (HACCP) programme and sanitation programme requirements.

Fish export license Any person who is not an operator of a registered establishment may apply for a fish export license. The application requires information that identifies the name and location of the business, as well as provides a description of the operations the applicant intends to conduct. Also required is a system for identifying the type and quantity of the fish product in each shipment, and a description of the system used by the exporter for tracing forward to the first recipient of the fish product.

Suspension or revocation of registration or export license The regulation describes conditions under which establishment registrations or fish export licenses may be suspended or revoked, as well as the appeal process for reinstatement.

Part II: Labelling requirements Part II of the Fish Inspection Regulation covers labelling requirements, and includes requirements for labelling every can of fish. The required information must be correctly and legibly marked in English or in French and includes: (a) (b) (c) (d)

The common name of the fish; In the case of fish other than shellfish and crustaceans, the net weight of the contents; In the case of shellfish and crustaceans, the drained weight of the contents; The name and address of the person by whom or for whom the fish is processed or by whom it is distributed; and (e) The ingredients in each can, where there is more than one ingredient therein: (i) By listing them in descending order of their proportion in the can; or (ii) By stating the proportion of each ingredient in the can. Part II also describes the specific requirements for describing the style of product packed, location on the label for specific label elements, and relative height of letters used for required label information. The regulation also describes label requirements for fish products other than canned fish. Other fundamental requirements for labelling include:

r r r

The label information must not be false, misleading or deceptive. No person shall mark or label any fish or container of fish with the designation ‘Processed under Government Supervision’ or ‘Canada Inspected’ or ‘Approved for further processing’ without the consent of the President of the Agency. No person shall mark or label a container of fish with a quality designation or sell a container of fish that is so marked or labelled unless: (a) A standard for that quality has been specified in these regulations; and (b) The fish in that container meets that standard.

Legal requirements for producers selling canned fish into Europe Table 2.2

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Product identity.

Product

First letters of code marking

1. Salmon or Blueback Chum Coho Pink Sockeye Spring Steelhead Mixed species of minced salmon 2. Lobster 3. Tomalley or lobster paste 4. Lobster cocktail

B K C P S T H M L LT LC

Part III: Container coding and case marking Container coding Every can of fish that is packed in a registered establishment shall be embossed or otherwise permanently marked in a manner that is visible, permanent and legible with code markings that: (a) Identify the establishment; (b) Indicate the day, month and year of processing; and (c) Identify the product contained therein in accordance with Table 2.2. A copy of the key to every code marking required by this section shall be sent to the President of the Agency each year before the commencement of processing operations. Case marking Every carton and case in which containers of fish are packed at an establishment shall be legibly marked on one end in such a manner that the name of the establishment and the day, month and year of processing can be determined by an inspector.

Part IV: Canned fish General requirements for canned fish Part IV of the Fish Inspection Regulation includes some very general requirements applicable for processing of all canned fish, as well as specifications for a number of finfish and shellfish species. The specifications include requirements for correct species identification and declaration, as well as packaging and weight requirements. The species and canned products listed in the regulation are lobster, clams, mussels, oysters, lobster cocktail, tomalley, lobster paste, salmon, tuna and sardines. For salmon and tuna, the regulation includes both scientific names and common names to be used for designating products after canning. General requirements include:

r r

All canned fish shall be sterilised by a method approved by the President of the Agency. All canned fish shall have sufficient vacuum such that they would not bulge when the product is heated to 95◦ F.

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All registered establishments that conduct canning process operations shall comply with all thermal process requirements set out in the Facilities Inspection Manual (FIM) – specifically the requirements in Chapter 13, Subject 1 of the Manual for thermal process control for canned fish. Proper training or experience to perform or supervise the thermal process operation. Registration of facilities that mechanically screen canned fish products for container integrity.

2.6.7 Additional resources for Canadian requirements for canned fish CFIA Facilities Inspection Manual 4 The FIM provides guidance for inspectors as well as processors for verifying compliance with regulatory requirements. The Manual is an excellent resource and learning tool, as it not only describes the regulatory requirements and compliance criteria but also provides a brief explanation of the intent of the requirement. Like many guidance documents, the Manual is continuously updated as new information becomes available. The excerpt below is from the FIM table of contents, and identifies chapters and subjects in the guidance that apply specifically to canned fish operations. The FIM also contains general requirements (e.g. Good Manufacturing Practices, GMPs) that may apply to canned fish as well as other fish or seafood products. Chapter 5 COMPLIANCE GUIDELINES Subject 1 Subject 2 Subject 3

Facility Compliance Requirements – Fish Inspection Regulations, Schedules I and II Canneries Compliance Guidelines for Mechanical Can Screening Operations Using Double-dud Detector and Checkweigher

Chapter 6

INSPECTION OF FISH PROCESSING OPERATIONS FOR COMPLIANCE WITH THE REQUIREMENTS FOR PROCESSING OPERATIONS – FIR (SCHEDULE II)

Subject 2

Canneries

Good Importing Practices5 Good Importing Practices (GIP) for food is a voluntary code of practice to be used as a guideline for Canadian importers. CFIA is considering the use of GIP to assist in assessing importers on their ability to ensure imported food meets Canadian legislation. The GIP include principal statements that attempt to capture the intent of the guideline while allowing flexibility in addressing specific products or processes. Where intent of requirements is not clear, rationales are included when the principal statement can be further clarified through additional explanation. Assessment criteria include factors considered in assessing adherence to GIP objectives, as expressed in the principal statements. The CFIA considers these factors during the course of its risk-based investigation or inspection activities. 4

5

Facilities Inspection Manual: http://www.inspection.gc.ca/english/anima/fispoi/manman/fimmii/toctdme. shtml. Good Importing Practices: http://www.inspection.gc.ca/english/fssa/imp/goodbonne.shtml

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The GIP are divided into the following eight general categories: 1. 2. 3. 4. 5. 6. 7. 8.

Control of imported product Equipment Premises Sanitation and pest control Personnel Transportation and storage Records Complaint handling and recalls

Guide to Canadian Regulatory Requirements and Examination Procedures for Imported Fish6 This guidance document provides importers with a brief narrative description of key regulatory requirements, including import sample inspection protocols. The guidance also provides a brief overview of commodity specific requirements, including those for canned fish products. While the document is not a comprehensive summary of all applicable regulation, it does provide a good common language review of inspection policies and procedures that are in place to determine compliance with requirements for safety, wholesomeness, composition and labelling as they relate to imported fish products.

2.7 2.7.1

UNITED STATES REQUIREMENTS Public policy, inspection and enforcement agencies

The U.S. Food and Drug Administration (FDA) The U.S. FDA is a scientific regulatory agency responsible for the safety of the nation’s domestically produced and imported foods as well as cosmetics, drugs, biologics, medical devices and radiological products. FDA is recognised internationally as the leading food and drug regulatory agency in the world. FDA’s responsibility in the food area generally covers all domestic and imported food except meat, poultry, and frozen, dried and liquid eggs, which are under the authority of the U.S. Department of Agriculture. FDA’s authority extends to products in interstate commerce. Products that are shipped within the Unites States are considered to be in domestic commerce, whereas products entering the United States from foreign suppliers are considered imports and have additional regulatory requirements. Products that are shipped between states and territories of the United States and products that are imported are considered to be in interstate commerce. Products that are manufactured in the U.S. states or U.S. territories and exported are also regulated by FDA; however, manufacturers may exercise provisions of the Federal FDC Act and supporting regulation that exempt products intended for ‘export only’ from certain requirements of the Act. FDA is part of the executive branch of the U.S. Government within the Department of Health and Human Services (DHHS) and the Public Health Service. The two centres/offices within FDA that

6

Guide to Canadian Regulatory Requirements and Examination Procedures for Imported Fish: http://www. inspection.gc.ca/english/anima/fispoi/import/guidee.shtml.

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deal primarily with food products are the Center for Food Safety and Applied Nutrition (CFSAN) and the Office of Regulatory Affairs (ORA). CFSAN is a centre within FDA responsible for developing and implementing policy that upholds statutory and regulatory requirements that protect public health by ensuring that the nation’s food supply is safe, sanitary, wholesome and honestly labelled. ORA is the lead office for all field activities of the FDA. The ORA consists of regional and district offices that deploy the field inspection staff for enforcement of regulatory requirements for domestic and imported foods. Offices within ORA also evaluate and determine compliance with agency regulations.

State regulatory agencies In addition to federal requirements for food safety, each state also has an inspection agency that enforces state regulations that may be different from the federal regulations. State regulations may adopt federal requirements by reference, or may have their own requirements that meet or exceed those of the FDA.

2.7.2

Laws and regulations in the United States

As mentioned earlier in this chapter, food safety is legislated in the United States by statutory requirements, or laws, that are typically referred to as Acts. Regulations, or rules, are supporting requirements that implement the statutory provisions of the law. Regulations are published in the Code of Federal Regulations. The U.S. rulemaking process is intended to be open and transparent. Generally, rules are developed and finalised through the following process: 1. 2. 3. 4.

Advanced notice of proposed rulemaking is published in the Federal Register. Proposed rule is published in the Federal Register. Interim final or final rule is published in the Federal Register. Final rules are also published in the Code of Federal Regulations (CFR).

A defined comment period is typically requested at each of the first three steps of the process, and the public is encouraged to provide input to the rule-making process.

FDC Act 7 The Federal FDC Act was passed by Congress in 1938. The FDC Act is composed of nine chapters and an appendix. The FDC Act is the primary statute that provides FDA the authority to create and enforce regulations for foods in interstate commerce. The chapters most relevant to food products (including canned fish) are I–IV and VII–IX, and key components of these chapters are summarised as follows.

Chapter I Short Title: This chapter iterates the title as the Federal FDC Act. Chapter II Definitions: This chapter defines terms used in the FDC Act. 7

US Food, Drug, and Cosmetic Act: http://www.fda.gov/opacom/laws/fdcact/fdcact7a.htm.

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Chapter III Prohibited Acts and Penalties: This chapter describes activities specifically prohibited by the FDC Act. The fundamental prohibitions are:

r r r r

The introduction or delivery for introduction into interstate commerce of any food, drug, device or cosmetic that is adulterated or misbranded. The adulteration or misbranding of any food, drug, device or cosmetic in interstate commerce. The receipt in interstate commerce of any food, drug, device or cosmetic that is adulterated or misbranded, and the delivery or proffered delivery thereof for pay or otherwise. The introduction or delivery for introduction into interstate commerce of any article in violation of section 404 (re: microbial contamination of food), 505 or 564 (re: drugs and medical devices).

Chapter III describes conditions under which civil or criminal penalties may be imposed for violations of the Act, including judicial actions that may result in monetary fines or seizure of products found to be in violation of the Act.

Chapter IV Food: The two key sections in Chapter IV are the following. Section 402 describes in detail the considerations necessary to determine whether a product is adulterated. Key to this description is whether the product consists in whole or in part of any filthy, putrid or decomposed substance; or if it is otherwise unfit for food; or if it has been prepared, packed or held under insanitary conditions whereby it may have become contaminated with filth, or whereby it may have been rendered injurious to health. Section 403 describes in detail the considerations necessary to determine whether a product is misbranded. Generally, canned fish would be misbranded if its labelling is false or misleading in any particular. Basic label elements required by the FDC Act are (1) the name and place of business of the manufacturer, packer or distributor; and (2) an accurate statement of the quantity of the contents in terms of weight, measure or numerical count. The Act also considers deceptively packaged foods to be misbranded. Other label elements are required under separate legislation, including the FPLA8 , the Food Allergen Labeling and Consumer Protection Act9 and the Nutrition Labeling and Education Act10 (NLEA), which amended the FDC Act, and requires most foods to bear nutrition labelling. The NLEA requires food labels that bear nutrient content claims and certain health messages to comply with specific requirements. Chapter VII General authority: Subchapter A includes the requirements most directly applicable to canned fish. Section 701 grants authority to the Secretary of Health and Human Services to promulgate regulation and conduct hearings as necessary to enforce the FDC Act. Section 702 provides the authority for the secretary to conduct examinations and investigations through employees of the department, or any duly commissioned health, food or drug officer or employee of any state or territory as necessary to enforce the Act. Other sections of Subchapter A include statutory provisions for factory inspection, access to records for product in interstate commerce, handling of confidential information, and applicant paid seafood inspection services. 8 9 10

Fair Packaging and Labeling Act: http://www.fda.gov/opacom/laws/fplact.htm. Food Allergen labeling and Consumer protection Act: http://www.cfsan.fda.gov/˜dms/alrgact.html. Nutrition Labeling and Education Act: http://www.fda.gov/ora/inspect ref/igs/nleatxt.html.

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Chapter VIII: Imports and exports Imports: This chapter describes the statutory requirements for imports and products manufactured for export. In essence, the chapter provides sampling authority to the secretary for the purpose of determining compliance with the Act. If an article has been manufactured, processed or packed under insanitary conditions, or restricted in sale in the country in which it was produced or from which it was exported, or the article is adulterated, misbranded, then such article shall be refused admission into U.S. commerce. This section also provides for efforts of importers to re-label or take other action on the product to bring it into compliance. If the product is not brought into compliance, it is refused admission or re-exported. Exports: Product manufactured in the United States that is intended to be exported is subject to the same requirements as domestic products; however, Section 801(e) of Chapter VIII of the Act provides stipulations for a determination that products intended exclusively for export markets (for export only) shall not be deemed adulterated or misbranded if the product: (a) (b) (c) (d)

Accords to the specifications of the foreign purchaser; Is not in conflict with the laws of the country to which it is intended for export; Is labelled on the outside of the shipping package that it is intended for export; and Is not sold or offered for sale in domestic commerce.

Chapter IX Miscellaneous: Chapter IX contains additional administrative statutes. Those of most relevance to food manufacturers are:

r r r r

Establishment of the FDA as a regulatory agency within the DHHS. Authorisation for the Commissioner of FDA to establish scientific review groups as are needed to carry out the functions of the FDA, and to appoint members of such groups. Grants the Secretary authority to Notify States when there is credible evidence that a shipment of imported food or portion thereof presents a threat of serious adverse health consequences or death to humans or animals. The secretary shall provide notice regarding such threat to the states in which the food is held or will be held. Authorises the secretary to make grants to assist in funding states, territories and Indian tribes that undertake examinations, inspections, investigations, and related activities.

2.7.3

Public Health Security and Bioterrorism Preparedness and Response Act of 200211

Commonly referred to as the ‘Bioterrorism Act’, this legislation was enacted in response to the terrorist attacks on the United States that occurred on 11 September 2001. The legislation is intended to prevent, prepare for, and respond to bioterrorism and other public health emergencies. Title III of the Bioterrorism Act includes four sections that are focused on the security of the U.S. food supply, from both domestic and imported sources. Exporters to the United States or importers receiving product in the United States must be familiar with theses four requirements, and particularly Section 305 (Facility Registration) and Section 307 (Prior Notice for Imports). Statutory and regulatory requirements promulgated for enforcement of the Bioterrorism Act are in effect and summarised as follows: 11

Bioterrorism Act: http://www.fda.gov/oc/bioterrorism/Bioact.html.

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Section 303: Detention Section 303 was self-executing and established a new section 304(h) to the Federal FDC Act to authorise FDA to detain an article of food for which there is credible evidence or information indicating such article presents a threat of serious adverse health consequences or death to humans or animals.

Section 305: Registration An Interim Final Rule was published on 12 October 2003 to implement provisions of the Section 305 Facility Registration requirements. The interim rule requires domestic and foreign facilities that manufacture/process, pack or hold food for human or animal consumption in the United States to register with the FDA.

Section 306 Records maintenance Section 306 required the issuance of regulations for the establishment and maintenance of records by persons (excluding farms, restaurants and some others) who manufacture, process, pack, transport, distribute, receive, hold or import food. The final rule was issued on 9 December 2004 and includes requirements that allow the secretary to identify the immediate previous sources and immediate subsequent recipients of food, including its packaging, in order to address credible threats of serious adverse health consequences or death to humans or animals.

Section 307: Prior notice Section 307 requires that importers or brokers provide FDA with essentially the same information usually provided to the Bureau of Customs and Border Protection when foods arrive in the United States. However, the information must be provided in advance to FDA in compliance with the following:

r r

No more than 5 days prior to arrival in the United States; and No fewer than: r 2 hours before arrival by land by road r 4 hours before arrival by air or by land by rail r 8 hours before arrival by water.

Advance knowledge of the requirements of the Bioterrorism Act, while not necessarily technical in nature, is important business acumen necessary to prevent unnecessary interruption of trade.

2.7.4

U.S. regulations

21 CFR 10812 : Emergency permit control This regulation includes the requirements for processors of LACFs, such as canned fish, to register the processing facility, and to file the scheduled processes used for cooking with FDA. The sections 12

Emergency permit control: http://www.cfsan.fda.gov/˜lrd/cfr108.html.

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of the regulation specifying the requirement for registration and filing are 21 CFR 108.35(c)(1) for registration, and 21CFR108.35(c)(2) for filing the scheduled process with FDA. Registration and filing are required for both domestic and foreign LACF producers whose product enters interstate commerce in the United States. It is also important to distinguish between the Food Canning Establishment Registration required by 21 CFR 108 and the Facility Registration required by the Bioterrorism Act. These are two distinct requirements, and both are mandated for any facility producing LACF for sale in the United States.

21 CFR 11013 : Current Good Manufacturing Practices (GMP) in manufacturing, packing or holding human food GMP are generally considered broadly applicable prerequisites to other food safety systems such as HACCP. As applied in this regulation, they cover areas of facility and equipment construction and design, sanitary food-processing operations, proper food handling and storage, and employee hygiene. At the time of writing, FDA has initiated an effort to modernise the GMP requirements. The topic of import control has been brought up through the public comment process and is likely to be considered as modernisation proceeds. Other considerations for modernisation include expansion of GMP to address allergen control, training, temperature control, written GMP, and records access.

21 CFR 11314 : Thermally processed low-acid foods packaged in hermetically sealed containers The LACF regulations are the cornerstone of regulatory requirements intended to ensure the safe production of LACF, including canned fish. These HACCP-based regulations include requirements for processing equipment, instrumentation used for monitoring critical factors of the process, container integrity examination evaluation, recordkeeping, identification and evaluation of process deviations, and corrective actions taken to address deviations.

21 CFR 12315 : Fish and fishery products Commonly referred to as the ‘Seafood HACCP Regulation’, this regulation applies to any person engaged in commercial, custom or institutional processing of fish or fishery products, either in the United States or in a foreign country. For the purpose of the regulation, processing is defined as handling, storing, preparing, heading, eviscerating, shucking, freezing, changing into different market forms, manufacturing, preserving, packing, labelling, dockside unloading, or holding fish or fishery products. The regulation requires that a hazard analysis be performed on each product covered under the regulation and requires an HACCP Plan whenever the hazard analysis reveals one or more safety hazards that are reasonably likely to occur. The regulation includes requirements describing the development, implementation and assessment of the HACCP Plan. The regulation requires importers to have a product specification that ensures the imported product is not adulterated under 13 14 15

Current GMPs: http://www.cfsan.fda.gov/˜lrd/cfr110.html. Low-acid canned foods: http://www.cfsan.fda.gov/˜lrd/cfr113.html. Seafood HACCP: http://www.cfsan.fda.gov/˜lrd/FCF123.html.

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FDC Act. Importers must also take ‘affirmative steps’ to verify compliance with the regulation, which may include: (a) Obtaining from the foreign processor the HACCP and sanitation-monitoring records required by this part that relate to the specific lot of fish or fishery products being offered for import; (b) Obtaining either a continuing or lot-by-lot certificate from an appropriate foreign government inspection authority or competent third party certifying that the imported fish or fishery product is or was processed in accordance with the requirements of this part; (c) Regularly inspecting the foreign processor’s facilities to ensure that the imported fish or fishery product is being processed in accordance with the requirements of this part; (d) Maintaining on file a copy, in English, of the foreign processor’s HACCP plan and a written guarantee from the foreign processor that the imported fish or fishery product is processed in accordance with the requirements of the part; (e) Periodically testing the imported fish or fishery product, and maintaining on file a copy, in English, of a written guarantee from the foreign processor that the imported fish or fishery product is processed in accordance with the requirements of this part; or (f) Other such verification measures as appropriate that provide an equivalent level of assurance of compliance with the requirements of this part. It is important to note that for fish and fishery products that are subject to the requirements of the LACF regulations in 21 CFR 113, such as most canned fish products, the HACCP plan need not list the food safety hazard associated with the formation of C. botulinum toxin in the finished, hermetically sealed container, nor list the controls to prevent that food safety hazard. An HACCP plan for such fish and fishery products shall address any other food safety hazards that are reasonably likely to occur.

2.7.5

Additional resources for U.S. requirements for canned fish products

The FDA Importer’s Guide for Low-Acid Canned and Acidified Foods16 This tool provides practical guidance to the importer in a question-and-answer format that captures the regulatory requirements for imported food products, including canned fish.

FDA’s Acidified and Low-Acid Canned Foods web page17 This FDA web page is an excellent resource for those producing acidified or LACF. The site includes quick access to various rules, regulations and guidance documents, as well as downloadable forms for registering the processing facility, and filing scheduled processes.

FDA’s Fish and Fishery Products Hazards and Controls Guidance18 The ‘Hazards Guide’ provides guidance to the industry on identifying significant hazards and on applying strategies for controlling the hazards in the context of a HACCP Plan. Use of the 16 17 18

Importers Guide for LACF: http://www.cfsan.fda.gov/˜lrd/lacf.html. FDA acidified and low-acid canned food web page: http://www.cfsan.fda.gov/˜lrd/lacf.html. Fish and Fisher Products Hazards and Controls Guide: http://www.cfsan.fda.gov/˜comm/haccp4.html.

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strategies in the hazards guide would normally result in a hazard analysis and/or HACCP Plan that would satisfy the requirements of the seafood HACCP regulation discussed earlier in this chapter. Other scientifically established strategies may be used, provided they provide an equivalent level of assurance of safety of the product. The Hazards Guide is also intended to serve as a tool to be used by federal and state regulatory officials in the evaluation of HACCP plans for fish and fishery products.

3

HACCP systems for ensuring the food safety of canned fish products

Alan Williams

3.1 INTRODUCTION HACCP is the acronym for ‘hazard analysis and critical control point’. Alternatives to the official meaning for HACCP have been suggested over the years but one that is quite apt, particularly when linked to a good measure of ‘common sense’, is ‘hazard analysis by cynical critical pessimists’. It is a system of food safety assurance based on the prevention of food safety problems and is accepted by international authorities as the most effective means of controlling food-borne diseases. HACCP is derived from ‘failure mode and effect analysis’, an engineering system which looks at a product and all its components and manufacturing stages and asks, ‘what can go wrong within the total system’ and ‘what can we do to stop it going wrong both now and in the future’. The HACCP system applied to food safety was developed in the 1960s jointly by the Pillsbury Company, the United States Army Laboratories at Natick and the National Aeronautics and Space Administration in their development of foods for the American space programme. It was necessary to design their food production processes to ensure the elimination of pathogens and toxins from the foods. As this could not be achieved by finished product testing alone, the HACCP concept was initiated. In 1971, the Pillsbury Company presented HACCP at the first American National Conference for Food Protection, since then the concept has been evolving in the food industry. The United States Food and Drug Administration incorporated HACCP into its Low-Acid Canned Foods Regulations (USFDA, 1979) and has applied HACCP to fish and fishery production processes (USFDA, 1995, 2001). The World Health Organization (WHO, 1995, 1996, 1997) and International Commission on Microbiological Specifications for Foods (ICMSF, 1988) have encouraged the use of HACCP on a global scale. The Codex Alimentarius Commission (CAC) promotes practical implementation of HACCP systems in the food industry (CAC, 2009). The Food Hygiene Committee of Codex has documented a standardised approach to HACCP to be used by all its member countries (CAC, 2009: 23–33). Codex standards, guidelines and recommendations have been identified as the baseline for consumer protection and have become the reference for international food safety. Within Europe, systems based on HACCP principles have been incorporated into the EC food hygiene regulations and also feed legislation (DG SANCO, 2005; European Union, 2004a, 2004b, 2005). A number of other countries have mandatory requirements for HACCP, particularly for seafood. HACCP has a fundamental role within industrial standards, such as the British Retail Consortium Global Standard Food (BRC, 2008) and the International Food Standard (IFS, 2007). Food safety management systems based on the Codex guidance are a specific requirement for both these standards. An international food safety management standard has been developed by the International Organisation for Standardisation (ISO, 2005a); this ISO 22000 standard integrates many of the requirements of the international standards for Quality Management Systems (ISO 9000 series), with

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HACCP principles based on the Codex guidance and prerequisite programmes (PRPs). Although ISO 22000 is stated to be suitable for all organisations in the food chain, many authorities have highlighted the difficulties small or less developed businesses have in developing and implementing HACCP systems. This has led to the development of sector-specific generic guides to HACCP. Some useful websites for Generic HACCP systems particularly for seafood and the canning of fish products can be seen in Appendix 1. The aim of this chapter is to outline the principles of HACCP and provide guidance on how HACCP systems may be developed and implemented by, in particular, manufacturers of canned fish products. A number of examples of the application of the HACCP principles are provided; these are only intended to illustrate the type of information and approaches that may be taken.

3.2

THE HACCP PRINCIPLES

HACCP is a system which identifies specific hazard(s) (i.e. any biological, chemical or physical property that adversely affects the safety of the food) and specifies measures for their control. The system consists of the following seven principles (cf. CAC, 2009): Principle 1

Principle 2 Principle 3 Principle 4 Principle 5 Principle 6 Principle 7

Conduct a hazard analysis. Prepare a flow diagram of the steps in the process. Identify and list the hazards together with their causes/sources, conduct a hazard analysis to determine if the hazards are significant for food safety and specify the control measures. Determine the critical control points (CCPs). A decision tree can be used. Establish critical limit(s) which must be met to ensure that each CCP is under control. Establish a system to monitor control of the CCP by scheduled testing or observations. Establish the corrective action to be taken when monitoring indicates that a particular CCP is not under control or is moving out of control. Establish procedures for verification to confirm that the HACCP system is working effectively; this should also include validation and review activities. Establish documentation concerning all procedures and records appropriate to these principles and their application.

N.B. The wording given in italics is not included in the principles of HACCP as documented by the CAC (2009) but is included here as additional explanatory notes.

3.3 PREREQUISITE PROGRAMMES Within any food operation, there will be many hazards or sources of contamination that are of a ‘generic’ or site-wide nature; i.e., they may occur at many steps of the process and are not specific to a particular process step, e.g. environmental conditions. The control of these ‘day-to-day’ potential hazards is normally part of good manufacturing practice or good hygiene practice; i.e., they are a pre-requirement to HACCP and they should be in place to underpin the HACCP system. The term ‘prerequisite programmes’ has found widespread use to describe these measures that provide the basic environmental and operating conditions that are necessary for the production of safe and wholesome foods (AIB International, 2006; BSI, 2008;

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Canadian Food Inspection Agency, 2007; NACMCF, 1997; USFDA, 1986). Loss of control could result in a low-risk safety issue, an economic issue or a quality defect. The PRPs cover three key areas, namely the premises, personnel and raw materials/product. Typical examples include: Premises r Building design location construction and maintenance; r Layout to ensure appropriate flows for personnel, product/raw materials and waste; r Good hygienic design, construction and installation of equipment; r Planned preventative maintenance and calibration schedules; r Cleaning schedules and procedures for equipment, premises and external areas; r Pest control programme; r Control of chemicals (e.g. cleaning chemicals, solvents, inks and lubricants); r Provision and maintenance of appropriate services (e.g. water, steam, ice and air); r Appropriate lighting and ventilation; r Control of glass and hard brittle plastic and other foreign bodies; r Programme of internal audits (e.g. house keeping and inspections against glass and hard brittle plastic registers); r Temperature-controlled storage/despatch and production areas (where appropriate); and r Waste management. Personnel r Personal hygiene and appropriate behaviour procedures, including rules for protective clothing, jewellery, eating, smoking and hand washing – these rules should apply to both staff and visitors to the premises; r Appropriate medical control of food handlers, visitors and contractors – these rules should include medical screening and sickness reporting; r Use of suitable waterproof dressings for cuts and wounds; r Effective laundering of protective clothing; r Specific procedures for the wearing of gloves (where relevant); r Appropriate training programmes and procedures for personnel; r Appropriate personal hygiene facilities should be provided (e.g. toilets, locker rooms, changing areas and hand washing). Raw materials/product r Effective procedures for supplier approval and control; r Agreed specifications for raw materials, including packaging; r Raw materials and finished products should be stored and delivered under clean conditions; r Materials and products should be recorded in a system that provides traceability and allows rapid and accurate recall; r Procedures for the control of non-conforming product (e.g. quarantine, rework and disposal); r Specifications for finished products; r Labelling: Clear product information and customer/consumer instructions provided as appropriate; r Customer/consumer complaints procedures; and r Transportation procedures for raw materials and finished product – ensuring transport under controlled temperature conditions, where appropriate. Further useful guidance may be found in relevant Codex documents, legislation, codes of practice and sector-specific industry guides.

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The PRPs provide a solid foundation on which the HACCP system can be based (NACMCF, 1997) and thus are normally expected to be in place before the HACCP plan is developed (CAC, 2009). It is vital that the PRPs are confirmed to be working effectively by the HACCP team, and routinely as part of the scheduled verification activities. If the PRPs are not in place and maintained, food safety management will not be effective and may cause the HACCP system to fail. The need for additional or improved PRPs may become apparent to the HACCP team during the hazard analysis; it is important for this reason that the HACCP team consider all hazards during this stage independent of the PRPs thought to be in place already. There may be instances where hazards that are normally considered to be ‘site-wide’, and thus managed by the PRPs, will need to be included in the HACCP plan at specific process steps, e.g. ensuring personal hygiene in a manual handling operation in a high care environment. Within ISO 22000 these would be called ‘operational prerequisites’; some users classify operational prerequisites as those control measures that cannot be monitored continuously or under ‘real-time’ conditions. Effective PRPs enable the HACCP system to be focused on the significant product and process food safety hazards that require specific control to assure consumer safety. By ‘screening out’ the general hazards, the identification of the true CCPs is made easier and may result in the identification of a relatively small number of CCPs and a more streamlined HACCP plan that can be effectively managed (Wallace and Williams, 2001). PRPs will need to be documented, and records should be maintained. This should also include evidence of their effectiveness.

3.4 HOW TO SET UP AND CONDUCT AN HACCP STUDY FOR CANNED FISH PRODUCTS The material in this section is based on procedures published by CAC (2009) and outlined by workers in this field (ILSI Europe, 1998, 2004; Mayes and Mortimore, 2001; Mortimore and Wallace, 1998; NACMCF, 1997). Specific details about canning, HACCP and fish processing/fish canning can be found in Horner (1992), Bratt (1995), USFDA (2001), Ababouch (2002) and Seafood Products Association (2008).

3.4.1 How to conduct an HACCP study HACCP systems should be underpinned by adherence to general principles of food hygiene, appropriate industry codes of practice and appropriate food safety legislation. The PRPs, outlined in Section 3.3, are required to be in place prior to the application of the HACCP principles. The company must select the HACCP approach most applicable to their operation; they may decide to look at all products or process lines on an individual basis (linear approach) or they may combine similar products or processes into modules (modular approach). In some instances, pre-developed HACCP plans may be appropriate (generic approach).

r r

Linear: The term ‘linear approach’ is given to the application of HACCP to products or process lines on an individual basis. This type of approach is most applicable to those food operations with relatively few products or simple processes. Modular: For more complex operations or those with many different products, linear approaches may not be appropriate and the modular approach would be more applicable to these situations. With the modular approach, groups of linked process steps or products are brought together

HACCP systems for ensuring the food safety of canned fish products Stage 1

Obtain senior management commitment

Stage 2

Define the terms of reference/scope of the study

Stage 3

Select the team

Stage 4

Describe the product and process

Stage 5

Identify intended use of the product

Stage 6

Construct a process flow diagram

Stage 7

On site confirmation of the flow diagram

Stage 8

List all potential hazards associated with each process step, conduct a hazard

55

analysis and determine the measures to control the identified hazards Stage 9

Determine the CCPs

Stage 10

Establish critical limits for the control measures at each CCP

Stage 11

Establish a monitoring system for each CCP

Stage 12

Establish a corrective plan for each CCP

Stage 13

Perform validation, verification and review activities

Stage 14

Establish documentation and record keeping

Fig. 3.1 Stages in applying the principles of HACCP. CCPs: critical control points; HACCP: hazard analysis and critical control point.

r

into modules. Each module is then examined on an individual basis. The modules are brought together to make the complete HACCP plan (see Appendix 2). Many food operations have found it useful to combine the linear and modular approaches. Generic: Company, sector or national generic HACCP plans may also be available to guide companies through the application of the HACCP principles. These can be very useful for, in particular, small and/or less developed food operations; however, the information must be fully checked for applicability to the actual operation as it is very unlikely that two operations will be identical in all respects. In the majority of cases, they need to be modified by the user, but they do provide a very good starting point.

Campden BRI (2009) identifies 14 stages to address when developing an HACCP study, 7 preparatory stages and then the 7 principles (see Figure 3.1). The first two stages are in italics in Figure 3.1 to show that this ‘Application Route’ differs slightly from the Codex ‘Logic sequence’, where they identify 5 preparatory stages before the application of the 7 principles resulting in 12 stages to their ‘Logic sequence’ (CAC, 2009).

3.4.2 Preparatory Stage 1: Management commitment In order to carry out an HACCP study senior management will have to appoint the HACCP team leader/chairperson and ensure the availability of the necessary team members for a number of

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study periods. The HACCP team is likely to meet several times depending on the complexity of the process under study and the number and types of hazards to be identified. Before any HACCP study begins, the team leader/chairperson must ensure that senior management of the company is committed to providing the necessary resource for the study to be completed and implemented, together with the resource to review and update the study. Without such commitment there is no point in beginning a study. To help provide evidence of management commitment, some food operations have a Food Safety Policy or include a statement on HACCP within their Quality Policy. Such policies should clearly define the food safety objectives and should be regularly checked and reviewed. Many food operations have also included an introductory statement from senior management in the HACCP plan for the same reason. Senior management must ensure that the responsibilities for key personnel have been defined; this would include those responsible for food safety and HACCP; this includes ensuring clear communication and reporting channels are in place. Ongoing management commitment is also needed to ensure regular reviews of their quality and production systems that are carried out; this will include the HACCP system.

3.4.3

Preparatory Stage 2: Define terms of reference/scope of the study

Terms of reference (TOR) or scope of the study should be clearly defined to help the HACCP team focus on the key issues. This will include:

r r r r

Determining the approach to be followed; Defining the product/process; Stating the start and end points of the study; and Defining the hazards to be considered.

In order for the study to proceed quickly, it is essential that the TOR are agreed and stated clearly at the outset. The hazards to be considered should be clearly stated here (i.e. biological, chemical or physical hazards – or any combination of these). It is also important that the objective of the study is defined (i.e. whether product safety only or whether microbiological quality aspects [i.e. spoilage] are also to be considered). It is recommended that the hazards are precisely defined, e.g. specific pathogenic organisms (such as Clostridium botulinum, Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus) or specific physical hazards (such as metal, glass and hard plastic). The TOR must also clearly state whether product is to be judged safe at the point of despatch, or at the point of consumption by the user. The start point of the study should be clearly defined (to include all raw materials and ingredients), as should the end point. If the completed HACCP study is supported by, and interrelates with, other documents, e.g. PRPs or those that form part of a Business Management System, this should be stated in the TOR to help to clarify the relationship. Sources of information that were used during the development of the HACCP plan should also be listed. This list may include legislation, codes of practice, guideline documents, relevant scientific literature and sources of HACCP guidance. By stating this supporting information, the food company can provide more confidence in the final HACCP plan.

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3.4.4 Preparatory Stage 3: Select the HACCP team An HACCP study will require the collection, collation and evaluation of technical data, examples of which are given in Stage 6, and it is best carried out by a multi-disciplinary team. The use of such teams is known to improve greatly the quality of data considered and therefore the quality of decisions reached. For HACCP studies to succeed it is important to:

r r r r

Select team members with relevant skills and expertise; Define the roles within the team (document these, including details of, relevant training in HACCP, qualifications and experience); Maintain the HACCP team over time; and Maintain records of HACCP team meetings.

In most operations, the team should be able to draw on the following skills:

r r r r r r

A production specialist: It is essential that this individual is able to contribute details of what actually happens on the production line throughout all shift patterns. A technical/quality assurance/quality control specialist: An individual who understands the microbiological and/or chemical hazards and associated risks for a particular product group. An engineer: An individual who has a working knowledge of the hygienic design and engineering operation/performance of the process equipment under study. Others: Other relevant specialists may be co-opted onto the team as necessary, e.g. buyers, operators, packaging and distribution experts, and a hygiene specialist. Team Leader: A person knowledgeable in the HACCP technique and/or the process should be nominated as team leader/chairperson of the team and be responsible for managing the study. Typically in most teams this is a technical or quality manager, however, appointing the production specialist as the team leader can help to promote ownership. Scribe: A person to take notes at HACCP team meetings and write the HACCP plan. Typically this is a technical/quality specialist (often the Team Leader) with good HACCP knowledge. The HACCP team must ensure that the HACCP plan is easy to read and understand.

Team members must have sufficient working knowledge of the process, product and the likely hazards to be able to contribute to the discussion of what actually happens on the production line, particularly if this is not revealed by the flow diagram. It is recommended that the team should not be made up of just managers. The team should be small, typically four to six persons, although further personnel may attend specific meetings as required (as non-core team members). In a small business, these skills may have to be represented by one person in this case, it is recommended that external support or information is sought carefully to ensure an effective HACCP study.

3.4.5 Preparatory Stage 4: Describe the product A full description of the finished product under study, or intermediate product if only part of the process is being looked at, should be prepared. It is essential for a successful hazard identification and analysis that the HACCP team should:

r r

‘Know’ their product and ‘What makes it safe?’ Understand the factors that could affect product safety.

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The product should be defined in terms of the key parameters which influence the safety of the product. Key parameters would include:

r r r r r r r

Composition (e.g. recipe, raw materials/ingredients and their origin); Chemical and physical structure/properties (e.g. AW , pH, acidity, salt%, emulsion, solids/liquid ratio); Processing (e.g. has product been heated and to what extent cooking, pasteurisation, sterilisation) and/or other preservation methods (e.g. brining, smoking, freezing) – what are the times and temperatures involved? Packaging system/materials (e.g. metal containers, aseptic packaging, glass bottles, vacuum) Storage and distribution conditions (e.g. product to be kept ambient, chilled or frozen, transport of canned goods in containers); Required shelf life under prescribed conditions (e.g. stated ‘use by’ date or ‘best before’ date); and Instructions for product use (e.g. storage, handling and cooking instructions).

There is a need to consider the potential for abuse/misuse of the product, e.g. during storage and transport. Fish canning operations may find it useful to include a brief description of the production process in terms of key equipment and conditions, as well as a clear outline of the heating and cooling conditions and the objectives of the process (e.g. ‘commercial sterility’ – what is it and how is it achieved with low-acid foods liked canned fish products). By completing this stage, the HACCP team will be better prepared to identify hazards, and it helps to ensure that all team members have a good understanding of the product.

3.4.6 Preparatory Stage 5: Identify intended use The intended use of the product by the customer or consumer and the consumer target groups should be defined to encompass any special considerations; for example, is the product designed for babies, young children or the elderly, and is the product ready-to-eat? Other vulnerable or sensitive groups could include consumers who are allergic to specific food ingredients, immune-suppressed or compromised and/or pregnant. The HACCP team needs to:

r r

Understand their consumers and how they might use/abuse the product (e.g. freezing of chilled or ambient products); and Determine if the product is focused on a vulnerable group.

This stage is useful to help the HACCP team identify other hazards that may become significant for vulnerable consumers. In practice, this stage is often combined with Stage 4.

3.4.7 Preparatory Stage 6: Construct a flow diagram Prior to starting hazard analysis, it is necessary to carefully examine the product/process (as defined in the TOR) and produce a flow diagram around which the study can be based. The HACCP team should:

r r

Know their process; Ensure that the flow diagram covers all relevant steps of the process;

HACCP systems for ensuring the food safety of canned fish products

r r

59

Gather information to help identify where hazards could occur; and Update the flow diagram as changes to the process occur.

The format of the flow diagram is a matter of choice; there are no rules for presentation. However, it is recognised a good practice to number all process steps and use arrows to indicate transfer from one process step to the next. Some organisations have found it beneficial to use rectangular boxes to clearly identify the process steps, or a range of different shaped boxes to denote different types of activity (e.g. raw material receipt, storage and mixing or preparation activities). Each step in the process (including process delays, recycle/rework loops and waste outputs) must be clearly outlined in the correct sequence from the selection of raw materials through to processing, distribution, retail or customer handling. The flow diagram should illustrate the introduction of utilities (e.g. steam and gas) and other materials that come into contact with the product (e.g. water and packaging materials). An example of a linear flow diagram illustrating a generic sardine canning operation (Mediterranean method) is shown in Figure 3.2. The HACCP team should also gather sufficient supporting technical data for the study to proceed. Examples of the supporting data may include, but are not necessarily limited to:

r r r r r r r

Floor plans of production and ancillary areas, and layouts of equipment and services (e.g. water, steam, air, vacuum and gas supplies); Time/temperature history of all raw materials, intermediate and finished products, including potential for delay; Equipment design features (including the presence of voids); Personnel routes; Routes of potential cross-contamination, including raw material movement and storage; Routes for removal of waste/by-product materials; and Segregation of high-/low-risk areas and clean/dirty areas.

Some food operations find it useful after having determined the CCPs at Stage 9, to return to Stage 6 and highlight the CCPs on the flow diagram.

3.4.8 Preparatory Stage 7: On-site confirmation of flow diagram As the flow diagram depicts the process steps that will need to be examined during Principle 1, the HACCP team must ensure that it is correct and that each process step is an accurate representation of the actual operation.

r r r

The flow diagram must be confirmed as correct. The confirmed flow diagram should be signed off and dated. The accuracy of the flow diagram must be maintained.

As the process changes, the flow diagram must be updated to reflect these changes. This will be an important element of the ‘Review’ activities (see Stage 13). The confirmed flow diagram and any amended versions should be signed off; all changes must be recorded.

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1

2

Receipt and storage of tomato puree 5 8

6

Frozen storage −18°C

Sauce preparation and heating 10

3

Receipt of frozen fish

19

17

Washing and inversion of empty cans

Manual filling of cans and inverting on racks

21

22

Circulation and filtration of hot sauce

23

24

26

25

Loading into crates under water

28

Disinfected water

29

16 Receipt and storage of empty cans and lids

Removing cans from racks 18 De-nesting and coding of lids Hot filling

Seaming

Hot water 80°C + detergent

Washing of cans

Loading retort

Sterilisation

Water cooling

30 Drying 12 hours

31

De-crating

32

Cartoning/coding

33

Shrink-wrap/trays Pallets Approval Signature .......................... Date of Validation ..........................

Fig. 3.2

Steam

Ink Steam

Steam

Storage

Salt reception and dry storage

Pre-cooking 105°C 25–30 minutes

27

Chlorination

12

20

Water

Mains water from town

11 Preparation of brine

Evisceration plus head/tail removal

Waste

Racks

13

Immersion and fluming in brine

15

Oil reception and storage

7

Chilled storage 0–5°C

14

Thawing

Water Brine 9

4 Receipt of fresh fish in boxes with ice

Shrink wrapping

34

Palletisation 35

Storage

Linear process flow diagram for a generic sardine canning process.

36

Despatch

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3.4.9 Stage 8: List all potential hazards associated with each process step, conduct a hazard analysis and consider any measures to control the identified hazards (Principle 1) By practical examination of the process, step-by-step, and using the flow diagram as a guide, the HACCP team should be able to:

r r r r

Make a list of all hazards at each process step; Analyse the hazards to determine the causes which are significant for food safety; Maintain records of the hazard analysis; and Ensure effective control measures are identified/put in place.

List the potential hazards The HACCP team should include all the hazards which may be present in the raw materials, which may be introduced during the process (e.g. contamination from the equipment, environment or personnel) and which could increase or survive at a process step; good sources of information on hazards in fish processing and fish canning can be found in Warne (1988), USFDA (2001) and Ababouch (2002). The HACCP team needs to make good use of the supporting technical data that have been previously gathered. For example, the team should consider the way in which the production process is managed and what could realistically occur that may not be covered by the flow diagram (e.g. process delays and temporary storage). Additionally, the condition of the food (e.g. intrinsic factors such as pH, Aw and temperature) must be considered to ensure that the causes of potential hazards are clearly understood. Taking the above into consideration, the HACCP team should develop its list of all conceivable hazards using structured idea generating sessions (e.g. ‘brainstorming’ or ‘mind mapping’). See Table 3.1 for a sample list of typical hazards that could occur in a generic fish-canning process.

Conduct a Hazard Analysis The HACCP team should next conduct a hazard analysis to determine which of the listed hazards are of such a nature that their prevention, elimination or reduction to acceptable levels is essential to the production of safe food. This can be divided into two activities:

r r

Clear and accurate description of the hazard including source or causes; and Assessment of the level of significance of the hazard with regard to food safety.

To define the hazard accurately, many HACCP teams have found it useful to use set descriptors, for example:

r r r r

Presence of the hazard (typically used when the hazard is already present in a raw material from the supplier); Contamination by the hazard (used when the hazard is introduced during the process); Growth of the hazard (typically used for microorganisms when they are able to increase their numbers); and Survival of the hazard (again typically used when microorganisms are not killed, inactivated or destroyed by a process step that was designed to do this).

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Table 3.1

Examples of typical hazards in a generic canned fish process.

Physical hazards (agents that will break teeth, choke people or cut them externally or internally)

Metal pieces (swarf, nuts & bolts, broken knives or machinery parts, nails, staples, fine stainless steel slithers from metal to metal contact) Glass sharps (from windows, lights and fittings, instruments) Hard brittle plastic Soft plastic Wood splinters (from pallets and boxes) Fish bones

Chemical hazards (agents that will cause external or internal chemical burning, induce immediate illness such as vomiting or intolerance/anaphylactic shock, or result in short- to long-term illness)

Cleaning chemicals such as acids and alkalis (e.g. caustic soaks of racking) Sanitising agents such as peracetic acid, hydrogen peroxide and halides such as chlorine or bromine Histamine Heavy metals (e.g. mercury, lead, cadmium) Rodenticides Allergens Chemical residues associated with the packaging materials Refrigerant (e.g. glycol, ammonia)

Biological hazards (agents that will cause food poisoning and other illness)

Vegetative pathogenic bacteria ◦ Salmonella spp. ◦ Escherichia coli (verocytotoxin) ◦ Listeria monocytogenes Toxin-producing pathogenic bacteria ◦ Staphylococcus aureus Spore-forming pathogenic bacteria ◦ Clostridium botulinum Parasites ◦ protozoa ◦ roundworms and tapeworms

To complete this hazard description, the source or causes of the hazard will need to be clearly defined; this is essential in order to help the HACCP team determine appropriate control measures. The significance of any hazard to the food safety of the finished product will need to be assessed (at this stage no attempt should be made to identify the CCPs). In practice, the decision process will need to take into account the risk associated with any hazard identified. Such considerations will always include a combination of the following:

r r r r r r

The likelihood of the hazard occurring and its consequent effects, e.g. previous company/industry experience or complaints and epidemiological data; The severity of the hazard, e.g. life-threatening/mild, chronic/acute; Numbers potentially exposed to the hazard, e.g. lot size and distribution; Vulnerability of those exposed, e.g. young/elderly, pregnant and allergic response; Survival or multiplication of microorganisms of concern; Production or persistence in foods of toxins, chemicals or physical agents;

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Table 3.2 Example of a scoring system approach to assess the significance of hazards (in this example, any hazard with a total score of three or more is deemed to be significant). Hazard

Severity (S)a

Likelihood (L)b

Significance (S × L)

Presence of glass fragments in glass jars from supplier

2

2

4

Introduction of wood splinters from damaged pallets into empty metal cans during storage

1

2

2

Introduction of pathogens due to post-process contamination of wet jars and cans.

2

3

6

a Severity of hazard. 1: minor injury to consumer; 2: consumer in hospital/serious short-term injury; 3: death of consumer/long-term illness leading to death. b Likelihood of hazard. 1: possibly could occur (unlikely to occur, but might); 2: probably could occur (likely to occur at some time but no history of it occurring); 3: definitely will occur (at some time it is going to happen or has occurred in the past).

r r

Sources or causes of the hazard or conditions leading to the above; and Contamination of raw materials, intermediate product and final product.

A number of tools have been developed to help HACCP teams carry out this part of hazard analysis; these include ‘scoring systems’, ‘quadrant graphs’ and ‘logic tables’ (Campden BRI, 2009). An example of the scoring system, one of the more popular methods used by food operations, is shown in Table 3.2. It must be remembered that the successful use of tools for hazard analysis, such as those noted above, depends on the experience and judgement of the HACCP team. The purposes of these tools are to make the hazard analysis stage more structured and logical, as well as providing documentary evidence that this vital stage has been performed. Although these tools may appear to be quantitative in nature, they are in fact qualitative because they still depend on the judgement of the team.

Maintain records of the hazard analysis The team must ensure that records of their decision-making process are maintained; this will enable them to show why a certain hazard was deemed to be significant. Even where a tool has not been used, records of the decisions made by the team should be maintained; it is important to include why hazards were discounted as not being significant. Examination of the records of hazard analysis should form an important part of any HACCP-based audit. As a result of the increased emphasis given to the use of risk assessment (CAC, 1999; ILSI Europe, 2007), data will become increasingly available from Microbiological Risk Assessments (Brown and Stringer, 2002; Campden BRI, 2007). These data may be useful in hazard analysis and in the validation of HACCP plans, in particular of critical limits. Until reliable data of this sort become available, HACCP team judgements will remain qualitative techniques as described above.

Identify appropriate control measures The next action for the HACCP team is to consider what control measures can be applied to each hazard.

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Table 3.3

Categorisation of control measures.

Control measure

Description

Prerequisite programmes (PRPs)

Activities associated with the process, which manage the basic environment and operating conditions of the facilities and process operation, i.e. hazards that are ‘generic’ (not specific to a particular process step). The consequence of a momentary failure could result in a low-risk food safety problem or quality defect. Alternatively referred to as Good Manufacturing Practice (GMP), Good Hygiene Practice (GHP) etc.

Operational PRPs

Activities that are associated with a particular process step and which manage specific significant hazards identified during hazard analysis, but not otherwise managed by critical control points. Regular checking of the effectiveness of operational PRP will be required. A loss of control would result in a low-risk food safety issue but timely correction of the problem must be taken. There must also be an evaluation of the impact of this loss of control on food safety.

Control measures applied at CCPs

Actions associated with the product at a particular process step, and are specifically applied to prevent or eliminate a significant hazard or reduce the hazard to an acceptable level. Continuous or ‘real-time’ monitoring of the effectiveness of the control will be required. Loss of control is likely to result in a high-risk food safety issue and will need immediate corrective action.

Control measures are those actions and/or activities that are required to prevent, eliminate or reduce the occurrence of hazards to acceptable levels (see Stage 13: Validation). Unfortunately, many teams confuse control with monitoring; monitoring is performed to check that the control measure is working effectively (see Stage 11). A good way to distinguish between control and monitoring is to note that control measures are applied all the time and to everything on the line at the appropriate point in the process (this includes pre-start-up checks), but they are not periodic checks or inspections or sampling activities which are examples of monitoring. Control measures need to be underpinned by the use of detailed procedures and specifications, e.g. detailed cleaning procedures and schedules, heat treatment specifications and agreed raw material specifications. The process may need to be redesigned or modified if control measures are not deemed to be effective. In a fish-canning operation, many of the measures used as controls will come from the PRPs; this further highlights the importance of PRPs in the production of safe food. In those operations working to the requirements of ISO 22000, hazards may be managed by PRPs, by operational PRPs or by controls at CCPs (see Table 3.3).

3.4.10

Stage 9: Determine CCPs (Principle 2)

CCPs are those process steps where it is essential to prevent or eliminate food safety hazards or reduce them to acceptable levels. In many situations, a CCP will be the last process step where a particular hazard can be controlled (i.e. the ‘Goal Keeper step’ for that hazard). Using professional knowledge, judgement and experience, measured with a good dose of common sense, the HACCP team should:

r r

Determine the CCPs; Consider the role of PRPs;

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Use a decision tree as tool if helpful; and Record the justification for all CCPs.

The correct determination of CCPs is vital to ensure that there is effective management of food safety; this is obtained through focussing the resources (e.g. monitoring and verification activities) at the CCPs. When considering where the CCPs are in a process, the HACCP team must avoid the trap ‘we test for it therefore it must be a CCP’ or the more serious reverse situation ‘we do not test for it therefore it is not a CCP’. The identification of a CCP for the control of a hazard requires a logical approach, and this may be aided by the application of a decision tree. The Codex decision tree is widely used (CAC, 2009); however, a number of decision trees have been developed, primarily with the aim of making the sequence of questions more user friendly. See Figure 3.3 for an example of a five-question decision tree (Campden BRI, 2009) based on a modified version of the Codex decision tree. When using a decision tree, each process step identified in the flow diagram must be considered in sequence. At every process step, the decision tree must be applied to each of the identified significant hazards in turn. To avoid identifying ‘false CCPs’ (especially for physical and chemical hazards), the Codex decision tree should not be applied to those hazards that are or will be effectively managed by PRPs. The decision tree illustrated in Figure 3.3 overcomes this problem by having the first question focussed on whether the hazard will be managed by the PRPs; if the answer is ‘yes’, no further actions are required except for the team to record which of the PRPs will manage this hazard. However, the team will have to ensure that the prerequisites are effective for this particular hazard. Records of the use of the decision tree and a copy of the actual tree used should be maintained; these will be important evidence to show during audits. If the HACCP team has not used a decision tree to help determine the CCPs then they should record the method used and the decisions reached. Although there is no limit on the number of CCPs that may be identified in a study, in practice, where the company has effective PRPs, there may only be a few CCPs. In addition to identifying CCPs, food operations working to the requirements of ISO 22000 will need to determine if hazards will be controlled by standard PRPs or operational prerequisites. When reviewing fish canning in the late 1980s, Warne (1988) identified a generic checklist of CCPs for the manufacturing of canned fish products. This checklist identified the following activities as CCPs:

r r r r r r r r r r

Raw and packaging material quality; Delay during preparation; Container washing; Filling temperature; Filling weight (liquid-to-solid ratio if applicable); Container size and adequacy of the hermetic seal; Retorting (including venting, process time, temperature and F 0 value, and cooling technique); Plant sanitation and cooling water chlorination; Line damage; and Transport and storage conditions.

Although many of these activities were linked to the careful management of the ‘critical factors’ associated with the safe production of ‘commercially sterile’ canned fish products (Bratt, 1995; Horner, 1992; USFDA, 1979), it was not clear if all the CCPs were to manage food safety hazards

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Q1 Is the hazard managed by the prerequisite programme(s)?

Yes

Not a CCP Record the prerequisite programme(s) Yes

No

Q2 Are control measures in place for the hazard? No

Q2a Is control necessary? (If yes, modify the step, process or product to obtain control)

No

Stop Not a CCP

Yes

Q3 Is the process step specifically designed to eliminate or reduce the hazard to an acceptable level?

Yes

No

Q4 Could contamination with the hazard occur at unacceptable levels or increase to unacceptable levels (if the controls failed)?

No

Stop Not a CCP

Yes

Q5 Will a subsequent process step eliminate the identified hazard(s) or reduce the hazard to an acceptable level?

No

Critical control point

Yes

Stop Not a CCP Fig. 3.3

Five question CCP decision tree. CCP: critical control point.

only or a combination of quality and safety hazards. Also the idea of using PRPs effectively in a balanced HACCP approach was not prevalent in HACCP guidance until much later in the 1990s. By effective application of PRPs, the HACCP plans in the late 1990s became much more focussed and fewer, but ‘real CCPs’ were identified. Typical CCPs in many fish canneries were:

r r r

Receipt of fish; Receipt of empty containers and lids; Sieving of ingredients;

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67

Filling and seaming/sealing of containers; Thermal processing (sterilisation, pasteurisation); and Container cooling/controlled drying (immediate post-process handling).

Following a careful review of hazards and effectiveness of PRPs, some canneries have focused their CCPs on those specifically managing microbiological food-poisoning hazards (i.e. can seaming, sterilisation and water cooling/can drying). This is clearly shown in the 2008 Salmon Control Plan, a voluntary cooperative agreement between the Packers and the Seafood Products Association (2008); here, there are three CCPs declared as:

r r r

Can seaming; Thermal Processing; and Water cooling of cans in the retort.

In the 2008 Salmon Control Plan, managing hazards associated with contaminated or damaged cans at goods in, during filling and after processing is done through effective PRPs and the satisfactory completion of the ‘Container Integrity Programme’ during final warehousing.

3.4.11

Stage 10: Establish critical limits for each CCP (Principle 3)

Having determined all the CCPs for the product/process under study, the team should then proceed to:

r r r r r

Determine the critical limits for the control measure(s) at each CCP; Ensure that they are measurable or observable in ‘real time’; Ensure that the critical limit is for the control and not the hazard; Where relevant, state any action limits, target values and tolerances; and Ensure that there is documented evidence that the critical limits have been validated.

The critical limit (or ‘bottom line’ for safety) is the value which separates a safe product from a potentially unsafe one. Some critical limits are defined in legislation (e.g. temperature and time conditions to be used for effective thermal processing), codes of practice and guideline documents, whilst others may be determined from the collection of experimental data during trials or from the advice of specialists with expert knowledge. For many practical purposes, a target level may also be specified, and the tolerance indicates the degree of latitude allowed between this and the critical limit. In some processes, an action limit has been found useful, as it provides early warning that a critical limit is being approached. The specific critical limits set for each CCP (as well as action limits, target levels and tolerances where appropriate) must represent some measurable or observable parameter related to the relevant control measures. Those that can be measured or observed in a timely manner are preferred. Examples of these include measurements of temperature, time, moisture level, pH, Aw ; chemical analyses; and visual observations of product and management/operational practices. Where critical limits are based on subjective data (e.g. visual observations/assessments), the company needs to provide clear guidance on requirements for compliance with practices or procedures or pictorial examples of what is acceptable (e.g. the use of photographs to define product appearance or texture). Failure to achieve a critical limit is termed a deviation and the appropriate corrective action must be initiated by the person responsible for monitoring.

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Details of how the critical limit was determined should be recorded; this should include sources of information or the actual data used. The stated critical limits will need to be validated to provide evidence that they are appropriate to control the specific hazard. A common mistake made by HACCP teams is to try and set the critical limit on the hazard and not the control measure (e.g. no broken glass in the product or numbers of food-poisoning bacteria/g). It is usually impossible to monitor such ‘limits’ or measure them in real time. It can also be appropriate to set operational limits for PRPs, in particular for the operational prerequisites.

3.4.12

Stage 11: Establish a monitoring system for each CCP (Principle 4)

Selection of the correct monitoring system is an essential part of any HACCP study. Monitoring is a planned sequence of observations or measurements of CCP control measures. The monitoring system describes the methods by which the business is able to confirm that all CCPs are operating within the defined critical limit (i.e. that they are ‘in control’) and it also produces an accurate record of performance for future use in verification. The monitoring system must be able to detect loss of control at the CCP. Ideally the monitoring method should be rapid enough to provide information in time for corrective action to be taken to enable control of the CCP to be regained. Monitoring systems may be either online, e.g. time and temperature measurements, or offline, e.g. measurement of salt, pH, Aw , total solids, and can seam dimensions. Microbiological testing methods are seldom suitable for monitoring CCPs, because of the time delays involved and the additional difficulty of having to interpret the results in the light of the known (or unknown) distribution of the organisms in the product. In some circumstances, rapid microbiological testing methods may be suitable for monitoring purposes, although the majority of microbiological testing activities have a vital role to play in verification (see Stage 13). Monitoring systems may be continuous (e.g. recording continuous process temperatures on a thermograph for a retort) or discontinuous (e.g. visual can seam inspection every 30 minutes or fish sample collection and analysis). Continuous systems provide a dynamic picture of performance, whilst with discontinuous systems, it must be ensured that the discrete sample monitored is representative of the bulk product. Ideally, an online continuous monitoring system should be chosen that responds dynamically to situations where the specified tolerance has been exceeded. In reality, the choice of monitoring systems available for a particular CCP may often be quite limited. The HACCP team should ensure that the monitoring system includes the following:

r r r r r r r

The responsibility for monitoring must be clearly stated – WHO is to act? WHAT are they to measure and HOW are they to act? All personnel performing monitoring must be trained and competent. WHEN are they to act? The frequency of monitoring must be stated and be appropriate. Clear work instructions or procedures may be required. Accurate records of the results of monitoring must be maintained. Monitoring records need to be reviewed.

All records and documents associated with monitoring CCPs should be signed by the person doing the monitoring and by a responsible designated person who reviews the stated results. All monitoring

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records must be accurate and include the date, time and the actual result of the monitoring activity carried out. Computer records, as well as paper records, may be used for monitoring. Checking PRPs: In addition to monitoring the controls at the CCPs, the PRPs must also be kept in place and operational as specified – the HACCP system will fail if they are not maintained. It is essential, therefore, that they are checked to confirm that they are working effectively. Checking of PRPs focuses on the implementation of the control. This is a different approach to CCPs where monitoring focuses on whether the control measure is effectively controlling the hazard. Checking of PRPs should be carried out frequently enough to ensure process and product safety; however, the frequency is likely to be less for a PRP than a CCP. Checking of operational PRPs may need to be more frequent than other PRPs, because by their nature, they require greater focus. Details of the PRP checking procedures should therefore be included or referenced in the HACCP study documentation (where relevant) – see Appendix 3. Because of the greater focus applied to operational PRPs, the requirements for the checking procedures may be the same as those for monitoring a CCP.

3.4.13

Stage 12: Establish a corrective action plan (Principle 5)

The HACCP team should specify the actions to be taken when the results of monitoring at a CCP show that there has been a failure to meet the critical limit (deviation) or when there is a trend towards loss of control. In the latter case, action may be taken to bring the process back into control before a deviation occurs. All corrective actions must be practical and achievable:

r r r r r r

Consider immediate actions to regain (maintain) control – ‘the now’ or ‘present’ actions; State what is to happen to product produced since the last good check – ‘past’ product actions; Investigate the cause of the deviation and take preventative action – ‘future’ actions; Assign clear responsibilities for these actions, personnel must be trained and competent; The relevant personnel should have the authority to take the stated corrective actions; and All corrective actions must be recorded.

Present: Immediate actions are needed to regain control (e.g. stopping a process, diverting to a holding stage and increasing a process temperature). Past: A decision needs to be taken about the product that has been produced during the time period that the CCP was ‘out of control’ (i.e. since the last good check). Suspect product should be identified (an effective traceability system will be required) and would normally be put on hold following company quarantine procedures. Authorised personnel must decide what happens to this product. Typically, there are only two options:

r r

If possible product could be reworked to make it safe; and If rework is not possible then the product must be destroyed.

Future: The cause of the deviation should be investigated and appropriate and timely remedial action taken. It is important to prevent the same issue occurring in the future. The company should confirm that appropriate remedial actions have been taken and have been effective. These remedial actions are additional to those needed to regain immediate control.

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Application of HACCP principles Preparation of the HACCP plan Validation of the HACCP plan Implementation of the HACCP Verification activities Fig. 3.4 point.

Review activities

Validation, verification and review activities within HACCP. HACCP: hazard analysis and critical control

Both corrective actions and destruction/rework actions should be documented, and accurate records maintained. These records are important as they provide evidence that potentially unsafe food did not reach the consumer. Remedial actions for PRPs: PRPs have to be checked to ensure that they are working effectively. If they are found to be ineffective, remedial action has to be taken. This is similar to the way that monitoring and corrective actions are taken for CCPs. Consideration should therefore be given to the remedial action necessary should checking of the PRPs indicate a loss of control (i.e. whether the PRP is being implemented effectively). The main focus of remedial action for PRPs will be on re-establishing control and preventing the same issues occurring in the future. However, the potential effect on the safety of the product should not be ignored. Because of the greater focus applied to operational PRPs, the remedial action procedures may be similar to those for corrective actions at CCPs, i.e. these actions would need to regain control, review the effect on product safety and prevent recurrence. Details of the PRP remedial action procedures should be included or referenced in the HACCP study documentation – see Appendix 3 for an example.

3.4.14

Stage 13: Verification (Principle 6)

This stage comprises three distinct activities:

r r r

Validation Verification Review

Figure 3.4 depicts when these activities normally take place within the development, implementation and maintenance of a HACCP system by a fish-canning operation and indicates:

r r r r r

The HACCP plan must be validated prior to implementation. There must be evidence that the HACCP plan is capable of producing safe food (validation). Auditing should be used to provide evidence of compliance with the HACCP plan (verification). There must be evidence that the HACCP system is working in practice (verification). The HACCP system must be reviewed by the HACCP team at least annually.

HACCP systems for ensuring the food safety of canned fish products

r r

71

There must be a mechanism to initiate a review of the HACCP system prior to a change occurring within the food operation or as a result of external factors. Records of validation, verification and review activities must be maintained.

Validation The main objectives of validation are to ensure that the hazards identified in the study are complete and correct, and that the selected controls for these hazards are suitable, i.e. hazards can be effectively managed if the stated measures are followed. The food operation must have evidence that the HACCP plan is scientifically/technically correct (valid). The validation should cover the overall HACCP plan and the specific CCPs, together with operational prerequisites and prerequisites, where it is relevant (CAC, 2008; ILSI Europe, 1999). It is the responsibility of the food business operators to validate their HACCP plans. A team may be required to perform the validation; this may consist of the HACCP study team plus additional internal or external specialists. It is useful to include personnel who were not directly involved in developing the HACCP plan; they will bring a ‘fresh pair of eyes’ and be better able to challenge the identified hazards and the stated measures to control these hazards (i.e. take on the role of ‘devils advocate’ and challenge decisions made). In larger companies, or where multiple teams are operating, validation may be a role for the Steering Group. The validation team should evaluate evidence supporting the selection, or exclusion, of significant hazards, the suitability of the stated controls, the acceptable levels for a particular hazard, the determination of the CCPs and the setting of the critical limits, and that the monitoring activities and corrective actions are realistic and will be adequate to assure food safety. Testing may be performed at the controls to check their efficacy, both prior to implementation and periodically thereafter. Examples of validation activities would include:

r r r r r

Thermal evaluation trials; Temperature distribution trials; Challenge testing; Mathematical modelling; and Document review of the HACCP plan (i.e. desk-top activity).

Validation should include the formal sign-off of the HACCP plan by the person ultimately responsible for product safety management at the food operation. Where the validation shows the HACCP plan is not capable of producing safe food, the plan must be amended and re-validated where necessary. Some validation will take place after implementation, for example as a result of review and maintenance activities of the HACCP plan (e.g. when a new significant hazard is identified, control measures are modified, or a new critical limit is set). Records of the validation activities must be maintained. They will form an important element of the evidence that will be subject to scrutiny during third party audits including official visits by public health personnel.

Verification The HACCP team should put into place procedures that can be used to demonstrate compliance with the validated HACCP plan and to determine its effectiveness once in use.

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There are two main aspects of verification: firstly, demonstrating conformance (i.e. personnel are following the stated procedures/work instructions and that the HACCP plan has been correctly implemented), and secondly, gathering information that the HACCP system and prerequisites are effective in practice (i.e. safety requirements are being met). Verification needs to be an ongoing activity. Verification should examine the entire HACCP system including all CCPs and relevant records, and PRPs where appropriate. The HACCP team should specify the methods and frequency of verification activities in the HACCP plan. Examples of key verification activities include:

r r r r r r r r

Internal auditing programmes of CCPs and relevant prerequisites (based on the actual practices at the CCPs and records of monitoring and corrective actions); External auditing programmes (supplier audits); Finished product and interim product testing (e.g. microbiological and chemical examinations of product samples); The findings of customer and third party audits; Analysis and trending of customer complaints; Sampling and testing of product already in the market place to look for unexpected safety problems (i.e. product buy-back); A review of deviations, corrective actions and resulting product disposal/rework; and Trending of monitoring results.

Records of verification activities must be maintained to provide evidence that the HACCP plan has been correctly implemented and that the controls are working effectively in practice.

Review The HACCP team should perform a formal scheduled review of the HACCP system. The frequency of the review should be based on a number of factors, typically these will include the nature of the product, its intended use and the product sector involved (especially where rapid changes can occur). Typically this formal review should be performed at least annually. In addition, it is absolutely essential to have a mechanism in place that will automatically ‘trigger’ or initiate a review of the HACCP system. These reviews should be performed by the HACCP team prior to the implementation of any changes that may affect product safety. The changes may be internally generated or may be due to some external factors. Examples of typical internal factors (not an exhaustive list):

r r r r r r r r

Change in raw material/ingredient/product formulation/packaging; Change in processing system (e.g. changes in method of preservation – such as addition of preservatives, water activity changes, going from a sterilisation to a pasteurisation activity); Changes in layout and environment of the factory; Modification to process equipment (e.g. new equipment, modification of existing equipment); Changes in cleaning and disinfection programme (i.e. a change to any supporting PRP); Failures in the system, e.g. corrective actions or the need for product recall/withdrawal; Changes in staff levels and/or responsibilities; and Receipt of information from the market place indicating a health risk associated with the product.

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Examples of typical external factors (not an exhaustive list):

r r r r r

Emergence of food-borne pathogens with public health significance; Changes in legislation, COPs, standards; New scientific/technical knowledge (e.g. new information on hazards and control measures); Unexpected use of product by the consumer; and Environmental changes/issues (i.e. local changes external to the food operation; climate changes).

It is recommended that the HACCP team detail the factors relevant to their operation in the HACCP plan. Data arising from HACCP reviews must be documented and form part of the HACCP recordkeeping system. It is essential that the records of review are accurate because they provide the evidence that the HACCP plan is up-to-date. Any changes arising from an HACCP review must be fully incorporated into the HACCP plan and may need to be validated. This is because such changes may result in modification of CCP control measures and/or critical limits. A system of management for the maintenance of the HACCP system is required, and its proper operation is essential. Review is the mechanism that drives this vital maintenance.

3.4.15 Stage 14: Establish documentation and record keeping (Principle 7) Efficient and accurate record keeping is essential to the successful application of HACCP by a food operation. Documentation of HACCP procedures at all process steps should be assembled and included in a manual and/or integrated into a controlled Business Management System.

r r r r r

The food operation must decide on the level and format of all documentation. An HACCP plan must be developed and maintained. Supporting documentation should also be in place and maintained. Records must be accurate and easily retrievable. Records must be retained for an appropriate period of time.

Examples of HACCP system documentation include:

r r r

The HACCP plan; List of hazards and details of the hazard analysis; and Supporting information: – Procedures and work instructions; and – Records, e.g. from monitoring and corrective action activities.

The HACCP plan is a key document within the HACCP system that shows what the food operation has done to address the 14 stages in applying the HACCP principles (see Figure 3.1) and should clearly state how the fish cannery is going to manage food safety. Some food operations have developed CCP summary charts that just detail the hazards, controls, critical limits, monitoring and corrective action activities at the CCPs. Although they are useful as a summary to show prospective clients and auditors, they must not replace the requirement for a full HACCP plan. The ‘conventional’ tabular format for presentation of HACCP plans is very useful in providing an immediate overview of the entirety of the study and in particular of the CCPs and control measures

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employed (see Appendix 5 for an example of ‘sterilisation’ and ‘water cooling’ in a generic fishcanning operation). There is limited space in the tabular format for the inclusion of great detail. An alternative method is to present the HACCP plan with each process step on typically an A4 sheet, allowing space for the inclusion of sufficient detail. An example of this approach is provided in Appendix 4.

3.5

IMPLEMENTATION

Implementation is the process of making the HACCP plan ‘live’ within the food operation. Prior to implementation, it is necessary that the conclusions reached in the HACCP plan are validated, i.e. are the specified control measures capable of eliminating or controlling the identified hazards to an acceptable level? The implementation process will need very careful planning, and some food operations have found it useful to appoint an implementation manager for this stage of HACCP. Some of the issues to consider for the effective implementation of an HACCP plan include:

r r r r r

Clearly defined pathways and responsibilities for communication to keep all staff informed; Involvement of operational personnel in the development of procedures and records; Training: Ensuring the right type and level of training is given relevant to role; HACCP visibility within the production environment; and Verification of effective implementation as soon as the HACCP system is operating.

3.6 ISO 22000 ISO 22000 aims to harmonise, on a global level, the requirements for food safety management for operations from all parts of the food chain (ISO, 2005a). It has been developed as an auditable standard for the food industry and combines the need for interactive communication, system management, PRPs and HACCP principles. It has been aligned with ISO 9001 and integrates application steps and the principles of HACCP as defined by Codex Alimentarius. Food operations working to the requirements of ISO 22000 will need to determine how identified hazards will be managed by PRPs, operational prerequisites or CCPs. ISO have prepared a Technical Specification 22004 (ISO, 2005b) that gives guidance on the application of ISO 22000 to assist individual food operations with the implementation of the Standard. A further guide document has been prepared by ISO/ITC (2007) to aid small and medium enterprises in both developed and developing countries. This guide takes the form of a checklist and could be useful during a gap analysis exercise.

3.7 CONCLUSIONS HACCP is a management tool that provides a more structured approach to the control of identified hazards than that achievable by traditional inspection and quality control procedures. It has the potential to identify areas of concern where failure has not yet been experienced and is therefore particularly useful for new operations. By using an HACCP system, control is transferred from end product testing (i.e. testing for failure) into the design and manufacturing of foods (i.e. preventing

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failure). There will, however, always be a need for some end product testing, particularly for verification purposes. Much of the effectiveness of HACCP is achieved through the use of a multi-disciplinary team of specialists. The team should have skills from relevant areas, e.g. microbiology, food science, production, quality assurance, food technology and food engineering. HACCP is a powerful system which can be applied to a wide range of simple and complex operations and is not restricted to large manufacturers. Although in this chapter we have focused particularly on fish-canning operations, HACCP can be used to assure food safety at all stages of the food chain.

REFERENCES Ababouch, L. (2002) HACCP in the fish canning industry. In Safety and Quality Issues in Fish Processing, edited by Bremner, H.A., pp. 31–53. CRC Press, Woodhead Publishing Limited, Cambridge. AIB International (2006) The American Institute of Baking GMP and Prerequisite Guide – A Foundation for Food Safety and HACCP. AIB International, Manhattan. Bratt, L. (1995) Heat treatment. In The Canning of Fish and Meat, edited by Footitt, R.J. and Lewis, A.S., pp. 178–211. Blackie Academic & Professional, an imprint of Chapman & Hall, Glasgow. BRC (2008) BRC Global Standard for Food Safety, Issue 5. British Retail Consortium, The Stationery Office (TSO), London. (www.brc.org.uk) Brown, M. and Stringer, M. (2002) Microbiological Risk Assessment in Food Processing. Woodhead Publishing Limited, Cambridge. BSI (2008) Prerequisite Programmes on Food Safety for Food Manufacturing, Publicly Available Specification – PAS 220:2008. British Standards Institute, London. (www.bsigroup.com) CAC (1999) Codex Alimentarius Commission – Principles and Guidelines for the Conduct of Microbiological Risk Assessment, CAC/GL-30. In Food Hygiene Basic Texts, 4th edition. Food and Agriculture Organisation of the United Nations, Rome. CAC (2008) Codex Alimentarius Commission – Guidelines for the Validation of Food Safety Control Measures, CAC/GL 69. Food and Agriculture Organisation of the United Nations, Rome. CAC (2009) Codex Alimentarius Commission – Food Hygiene Basic Texts, 4th edition. Food and Agriculture Organisation of the United Nations, Rome. Campden BRI (2007) Industrial Microbiological Risk Assessment – A Practical Guide, 2nd edition, Guideline No. 28. Campden BRI, Chipping Campden, UK. Campden BRI (2009) HACCP: A Practical Guide, 4th edition, Guideline 42. Campden BRI, Chipping Campden, UK. Canadian Food Inspection Agency (2007) Prerequisite programs. In Food Safety Enhancement Program Manual, Chapter 2, Section 2, pp. 8–28. (http://www.inspection.gc.ca/english/fssa/polstrat/haccp/manue/manuche.pdf) DG SANCO (2005) Health & Consumer Directorate General – Guidance Document on the Implementation of Procedures Based on the HACCP Principles, and on the Facilitation of the Implementation of the HACCP Principles in Certain Food Businesses, European Commission, Brussels. European Union (2004a) Regulation (EC) No. 852/2004 of the European Parliament and of the Council of 29 April 2004 on the hygiene of foodstuffs. Official Journal of the EU, L226, 3–21. European Union (2004b) Regulation (EC) No. 853/2004 of the European Parliament and of the Council of 29 April 2004 laying down specific hygiene rules for food of animal origin. Official Journal of the EU, L226, 22–82. European Union (2005) Regulation (EC) No. 183/2005 of the European Parliament and of the Council of 12 January 2005 laying down requirements for feed hygiene. Official Journal of the EU, L35, 1–22. Horner, W.F.A. (1992) Canning fish and fish products. In Fish Processing Technology, edited by Hall, G.M., pp. 114–154. Blackie Academic & Professional, an imprint of Chapman & Hall, Glasgow. ICMSF (1988) International Commission on Microbiological Specifications for Foods – Application of the hazard analysis critical control point (HACCP) system to ensure microbiological safety and quality. In Microorganisms in Foods, Vol. 4. Blackwell Scientific, Oxford.

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IFS (2007) International Food Standard, Issue 5. German Retail Federation and French Retail and Wholesale Federation. (www.food-care.info) ILSI Europe (1998) Food Safety Management Tools. ILSI Europe, Brussels, Belgium. ILSI Europe (1999) Validation and Verification of HACCP. ILSI Europe, Brussels, Belgium. ILSI Europe (2004) A Simple Guide to Understanding and Applying the Hazard Analysis Critical Control Point Concept, 3rd edition. ILSI Europe, Brussels, Belgium. ILSI Europe (2007) Using Microbiological Risk Assessment (MRA) in Food Safety Management. ILSI Europe, Brussels, Belgium. ISO (2005a) Food Safety Management Systems – Requirements for Any Organisation in the Food Chain (EN ISO 22000:2005). International Organization for Standardization, Geneva. ISO (2005b) Food Safety Management Systems – Guidance on the Application of ISO 22000:2005. Technical Specification (ISO/TS 22004). International Organization for Standardization, Geneva. ISO/ITC (2007) ISO 22000 Food Safety Management Systems. An Easy-to-Use Checklist for Small Business. Are You Ready? International Organization for Standardization/International Trade Centre, Geneva. Mayes, T. and Mortimore, S. (2001) Making the Most of HACCP – Learning from Others’ Experience. Woodhead Publishing Limited, Cambridge. Mortimore, S. and Wallace, C. (1998) HACCP: A Practical Approach, 2nd edition. Aspen Publishers, Inc., Gaithersburg, MD. NACMCF (1997) National Advisory Committee on Microbiological Criteria for Foods – Hazard Analysis and Critical Control Point Principles and Application Guidelines (adopted August 14, 1997). USFDA/USDA, Washington, DC. (http://www.cfsan.fda.gov/∼comm/nacmcfp.html) Seafood Products Association (2008) The 2008 Salmon Control Plan with Container Integrity Program and Example Canned Salmon HACCP Program. Seafood Products Association, Seattle, WA. USFDA (1979) as amended. Thermally processed low-acid foods packaged in hermetically sealed containers. In Code of Federal Regulations (CFR), Title 21, Vol. 2, Part 113. US Government Printing Office, Washington, DC. USFDA (1986) as amended. Current good manufacturing practice in manufacturing, packing, or holding of human food. In Code of Federal Regulations (CFR), Title 21, Vol. 2, Part 110. US Government Printing Office, Washington, DC. USFDA (1995) as amended. Fish and fishery products. In Code of Federal Regulations (CFR), Title 21, Vol. 2, Part 123. US Government Printing Office, Washington, DC. USFDA (2001) Fish and Fishery Products: Hazards and Controls Guide, 3rd edition. Centre for Food Safety and Applied Nutrition, Washington, DC. Wallace, C. and Williams, T. (2001) Prerequisites: a help or a hindrance to HACCP. Food Control, 12(4), 235–240. Warne, D. (1988) Manual on fish canning. FAO Fisheries Technical Paper 285. Food and Agriculture Organisation of the United Nations, Rome. World Health Organization (1995) Hazard Analysis and Critical Control Point System, Concept and Application. Report of a WHO Consultation with the participation of FAO, 29–31 May 1995. WHO/FNU/FOS/95.7. World Health Organization (1996) Training Aspects of the Hazard Analysis Critical Control Point System (HACCP). Report of a WHO workshop on training in HACCP with the participation of FAO, Geneva, 1–2 June 1995. WHO/FNU/FOS/96.3. World Health Organization (1997) HACCP, Introducing the Hazard Analysis and Critical Control Point System. WHO/FSF/FOS/97.2.

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APPENDIX 1: USEFUL WEBSITES (FOR HACCP GUIDANCE AND INCLUDING GENERIC HACCP PLANS IN SOME CASES) Food and Agriculture Organisation (FAO): http://www.fao.org World Health Organisation (WHO): http://www.who.int Codex Alimentarius Commission (CAC): http://www.codexalimentarius.net Canadian Government HACCP Generic Guides: http://www.inspection.gc.ca/english/fssa/polstrat/haccp/modele.shtml Canadian Food Safety Enhancement Program Manual: http://www.inspection.gc.ca/english/fssa/polstrat/haccp/manue/tablee.shtml Seafood Network Information Centre: Generic HACCP Plans: http://seafood.ucdavis.edu/haccp/Plans.htm Fish, Fillets (Non-scombroid): Generic HACCP Plan: http://www-seafood.ucdavis.edu/haccp/plans/fishfil.htm U.S. Food and Drug Administration: Seafood HACCP: http://www.cfsan.fda.gov/∼comm/haccpsea.html U.S. Food and Drug Administration: Fish and Fisheries Products Hazards and Controls Guidance http://www.cfsan.fda.gov/∼comm/haccp4.html EUROPA Activities of the European Union: Food Safety: http://europa.eu/pol/food/index en.htm EUROPA. Food Safety: Microbiological Criteria: http://europa.eu.int/comm/food/food/biosafety/salmonella/microbio en.htm DG SANCO Overview of Food and Feed Safety: http://europa.eu.int/comm/food/food/biosafety/hygienelegislation/index en.htm DG SANCO Food Hygiene Guidance Documents: http://ec.europa.eu/food/food/biosafety/hygienelegislation/guide en.htm European Law (Eur-Lex website): http://eur-lex.europa.eu/en/index.htm

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APPENDIX 2: MODULAR HACCP APPROACH FOR THE CANNING OF TUNA PRODUCTS, SHOWING TYPICAL ACTIVITIES WITHIN EACH MODULE Module 1: Raw materials Purchase and receipt of fish (fresh/frozen)/ingredients/packaging Storage of ingredients Ambient Bulk Chilled Frozen Storage of packaging Water/Steam/Ice Module 2: Preparation Thawing of frozen fish Pre-cooking and cooling Manual filleting, cleaning and portioning of fish Debagging of salt Sieving of bagged ingredients Weighing Preparation of brines and sauces Intermediate storage of brine and fish loins Module 3: Processing De-palletising of cans Inversion and washing of cans De-nesting/embossing/coding of lids) Forming of fish blocks and filling of cans Hot filling of oil or brine or sauce Lidding and seaming Basket loading and holding prior to retorting Retorting Water cooling and drying of cans Module 4: Packing Labelling Coding Shrink wrapping Palletisation Storage Despatch

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APPENDIX 3: EXAMPLE OF A TABULAR DOCUMENTATION FORMAT FOR PREREQUISITE PROGRAMMES Prerequisite Programme (PRP)

Hazard(s) controlled by the PRP

Glass policy

Introduction of glass from Glass is covered or guarded equipment and the environment (machinery, to prevent contamination lights, windows etc.) of goods

Checking procedures

Remedial actions

Scheduled inspection (at an appropriate frequency) of glass fixtures and fittings

Take appropriate action to remedy any defects Record actions taken

Glass breakage procedures are in place

Temperature control Where applicable raw materials are stored and despatched at chill temperature (≤5◦ C)

Supplier assurance Raw materials are sourced from reputable/approved suppliers. Purchasing of materials takes into account the source and the treatment that it may have undergone

Growth of food-borne pathogens due to time and temperature abuse

Scheduled check (at an Review procedures and appropriate frequency) of take appropriate action chill stores and despatch to remedy any defects vehicle temperature

Presence of food-borne pathogens, physical hazards and chemical hazards such as non-permitted pesticides due to contamination at previous stages in the supply chain

Review approved supplier Review suitability of list suppliers Supplier performance evaluated according to schedule

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APPENDIX 4: EXTRACT FROM A NON-TABULAR FORMAT HACCP PLAN APPROACH FOR CAN SEAMING (CCP 2) CCP No. 2 Process step no. 24 Double seaming of filled cans Hazard

Post-process microbial contamination leading to growth as a result of poor-quality double seams

Control measures

Double seaming machines are maintained according to defined service procedure,

Procedure CM/CCP2/0 Seamer machine manual, edition 2. Cans are closed according to can maker’s specified tolerances for actual overlap, tightness rating and % body hook butting (BHB).

Procedure for seamer operation CM/CCP2/02 Seam specification data sheet DS/CCP2/01 Personnel involved in seaming machine operation and seam measurement are suitably trained.

Procedure for training of seamer personnel T/CCP2/01 Critical limits

Seams are closed to comply with critical limits included within data sheet DS/CCP2/01 for relevant size of can. Critical values for seam acceptability include those for: • % BHB • Actual overlap • % Overlap • Free space • Seam tightness rating

Monitoring procedures Monitoring procedures are designed to check compliance with specification and include: • Continual visual and tactile checking of seams by crate filler operator

Procedure QA/CCP2/02 •

Recorded visual checking of ten cans per seaming head at 1/2-hour intervals by QA technician

Procedure QA/CCP2/03 •

Seam analysis by both projection and tear down, for each seaming head, at start up and at 4-hour intervals by QA technician

Procedure QA/CCP2/01 Corrective action

In the event that critical seam measurements are observed to fall outside the specified values the sequence of events should follow the corrective action procedure. This requires: • The immediate rechecking of results obtained • Notification of specified production, engineering and QA manager

HACCP systems for ensuring the food safety of canned fish products

Record keeping

•

Stopping of production

•

Identification and isolation of affected material

•

Resolution of the immediate situation and restart of manufacture

•

Resolution of the safety of affected cans

•

Corrective action procedure CA/CCP2/01

The following forms are required for completion • Seamer machine maintenance sheet R/CCP2/01 •

Double seam visual inspection report R/CCP2/03

•

Double seam projection analysis and tear-down report R/CCP2/02

•

Double seam non-compliance report R/CCP2/04

•

Double seam corrective action report R/CCP2/05

•

Seamer personnel training record TR/01

Verification procedure Procedure for the verification of the correct application of CCP 2

VP/CCP2/01

81

Process step

Sterilisation

Water cooling

Step No.

28 (CCP 3)

29 (CCP 4)

Introduction of pathogens from inadequately treated re-circulated cooling water

Consistent application of the scheduled thermal process based on ‘Brimful’ or guaranteed headspace, with a minimum product IT

Survival of spores of Clostridium botulinum due to under processing

Planned maintenance

Calibration; and

Trained staff ;

Correctly designed tanks and dosing system to ensure minimum contact time;

PRPs of:

Effective disinfection of cooling water

Planned maintenance

Calibration of instruments, recorder and alarm; and

Trained staff;

SOP sterilise;

PRPs of:

Control measures

Hazard/cause

No

No

Q1

Yes

Yes

Q2

No

Yes

Q3

Yes

Q4

Decision tree

No

Q5

Yes

Yes

CCP Yes/No

APPENDIX 5: EXTRACT OF A TABULAR HACCP CHART FOR CCP 3 STERILISATION AND CCP 4 IN THE GENERIC FISH CANNING FLOW DIAGRAM

Process step

Sterilisation

Step

28 CCP 3

Heat sensitive indicators must change colour.

Ref: Procedure SP01)

minimum venting/come up and cooking process temperatures and times ALL as per scheduled process for can size and product type –

minimum IT,

(Maximum time lapse between seaming and start of thermal process,

Target process will be above this.

All products must receive a thermal process value greater than F 0 = 3 minutes

Critical limit

After cooling and unloading, check and record that the ink jet codes on lids and heat-sensitive tape have changed colour.

Check the time the process temperature is reached on the MTI and record this together with the recorder readings; repeat these checks and record all data at the middle and end of the heating process as per Procedure SP01.

Prior to loading each basket into the retort, check the filling record for the time of filling and filling temperature for the first can loaded; record this on the Retort Process log (Record SP02) and note the overall hold time after seaming compared with the maximum permitted.

To check that the gauges and instrumentation are working and the settings for process temperature and time on the recorder/controller match the can size and product type prior to start up.

Trained cooker operator

Monitoring

All actions to be recorded on process log and form CAR-01.

If ink jet codes and heat-sensitive tape have not changed colour, then operator to quarantine the whole batch from the retort and inform the technical manager. Technical manager to carry out further investigations and take appropriate action according to the Disposal Procedure DISP-01.

Any deviation in process temperatures and times, then Operator to inform the technical manager who will confirm the appropriate process deviation procedure to be followed.

If product-filling temperature is below set limit or delay after filling is above maximum permitted time, Operator to put product on hold and inform the technical manager. Technical manager to confirm with operator the process deviation procedure to be followed.

Call the engineer, do not proceed with any processing of product. Engineer to fix problem, QA and production to confirm the correct can size and product type. Operator to start production when all has been corrected.

Cooker operator to follow corrective action procedure CAST-01. Actions to include:

Corrective action

Water cooling

29 CCP 4

There must be a measurable residual of disinfectant in the cooling water leaving the retort (e.g. for chlorine this must be a detectable free residual level of at least 0.5 ppm).

Critical limit

Record the level of sanitiser on the Retort Process Log SP02.

Following test procedures CW01 and using a valid Test Kit, a trained process supervisor to check that there is a measurable level of sanitiser in the cooling water exiting a retort at least twice per day during production.

Monitoring

SOP: standard operating procedure; IT: initial temperature; PRPs: prerequisite programmes.

Process step

Step

All actions to be recorded on form CAR-01.

Engineer to investigate the cause of the problem and take appropriate action.

Technical manager to determine the fate of the held product.

QA to be informed, product produced since the last good check to be identified and put on hold.

The frequency of checking the sanitiser to be increased so that every cooling cycle is now checked by the process supervisor until results are consistent.

Process supervisor to get the engineer to increase the dosage rate of sanitiser to the appropriate level.

Actions to include:

Process supervisor to follow the cooling water Corrective Action Procedure CACW01.

Corrective action

4

National and international food safety certification schemes

Harriet Simmons

4.1 INTRODUCTION Retailers and brand owners have a legal responsibility for their brands. If faced with a legal challenge from authorities, organizations and companies need to demonstrate a satisfactory ‘due diligence’ defence. This means that they have to ensure that every possible precaution was taken to prevent the problem. Certification offers retailers and brand owners one of the main tools to help them with their legal obligations. Retailers and brand owners in the United Kingdom are under constant pressure from a high level of enforcement and the strong need to preserve the integrity of their brands. It is not only UK brand owners and retailers who are asking for their suppliers to be certificated, but global brand owners and retailers also require certification of their supplier base.

4.2 FOOD SAFETY LEGISLATION Legislation covering food safety differs in detail worldwide, but generally requires food businesses to address the following issues:

r r r r r

To ensure the presence of a detailed specification which is lawful and consistent with compositional and safety standards and good manufacturing practice; To ensure they satisfy themselves that their suppliers are competent to produce the specified product, comply with legal requirements and operate appropriate systems of process control; From time to time make visits, where practical, to verify the competence of their suppliers or receive the result of any other audit of the supplier’s system for that purpose; To establish and maintain a risk-assessed programme for product testing or analysis; and To monitor and act upon customer complaints.

4.3 FOOD SAFETY MANAGEMENT SYSTEMS Food safety management systems generally include three components: – Quality management systems applied to food safety; – Hazard analysis and critical control point (HACCP) systems; – Prerequisite programmes and good practice, including good hygiene practices (GHPs), good manufacturing practices (GMPs) and good agricultural practices (GAPs).

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Quality management has been harmonised at the international level through the widespread acceptance of ISO 9001. Yet, although Codex Alimentarius addresses both HACCP and good practice, in particular through its general principles on food hygiene, there is no truly global certification programme in place for either HACCP or good practice. National certification schemes have proliferated to fill this gap, especially in industrialised countries where the major programmes include GlobalGAP, the British Retail Consortium (BRC), the International Food Standard (IFS), the Safe Quality Food (SQF) standard and the Dutch HACCP. There are more than 100 food safety and quality standards in the global food supply chain. A large number of food manufacturers and primary producers are certified against a number of these by their key customers. While these standards comply with Codex standards on the whole, their objectives and scope may vary. In fact, some deal with good practice, and some with quality management systems that integrate HACCP and others with entire food safety management systems. Likewise, some apply to farm producers, some to manufacturers and others to all food operators. In addition, the geographic scope of these standards is often limited in that they each tend to be recognised by buyers and retailers from the specific countries from where they originate.

4.4 CERTIFICATION: A BRIEF OVERVIEW A number of important concepts must be defined in order to better understand food safety certification. These include the following.

4.4.1 Standardisation The objective of standardisation is to set up a standard for a procedure or a product specification, to which every stakeholder adheres, in order to ease logistical procedures, facilitate trade and possibly improve quality if the requirements of the standard involve an improvement compared to common practices.

4.4.2 Standards Two types of standards exist: product standards (specifications and criteria for the characteristics of products) and process standards (criteria for the way the products are made). Food safety standards are essentially process standards whose aim is to improve the safety of the end products. Process standards can be further divided into two categories. On the one hand, performance standards establish verifiable requirements on processes, for instance a ban on pesticide use in farm production. In the food safety field, GAPs and GHPs represent such performance standards. On the other hand, management system standards establish criteria for management procedures such as documentation or monitoring procedures. In the context of food safety, such standards may demand HACCP planning. A standard can be the subject of a certification programme (such as the ISO standards for instance) or not (like the ones defined by Codex Alimentarius).

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4.4.3 Standard-setting body Standards can be set up by governmental institutions, by the private sector (buyers or suppliers) or even by certification bodies that want to set their own standards, perhaps on the basis of an existing standard.

4.4.4

Certification

Certification is a procedure by which a third party gives written assurance that a product or a process is in conformity with the corresponding standard. Thus, the certificate demonstrates to the buyer that the supplier complies with certain standards, which might be more convincing than if the supplier itself provided the assurance.

4.4.5 Certification programme A certification programme is the system of rules, procedures and management for carrying out certification, including the standard against which it is being certified.

4.4.6

Certification bodies

The certification programme is carried out by a certification body, which does the inspection and delivers the certificate. One certification body may execute several different certification programmes. The certification body must always be a third party, without any direct interest in the economic relationship between the supplier and the buyer. However, it is not always easy to guarantee independence and the absence of conflicts of interest of certification bodies, in so far as certification costs are borne by suppliers. Indeed, certification is increasingly becoming an industry in itself, with growing competition between certification bodies, which must balance the need to retain clients with the stringency of their standards.

4.4.7 Accreditation A certification body can carry out certification programmes only if it is evaluated and accredited by an authoritative body (typically a governmental or para-governmental institute), which ensures that the certification body has the capacity for carrying out certification and inspection in compliance with guidelines set by ISO, the European Union or some other entity. UKAS is the accreditation body in the United Kingdom. In addition, the certification body may require a licence from the standard-setting body, especially if it is a private standard-setting body, for the scope of its particular standard.

4.4.8 Good practice Good practice relates to basic requirements on the company’s activities, such as use of appropriate equipment, personnel hygiene, waste management etc. Standards on good practice can be called GAPs, GHPs or GMPs, depending on the sector to which these are being applied. Such standards can also be specific to a product sector (fruit and vegetables, meat products etc.). Good practice is often referred to as a prerequisite programme within standards with a wider scope.

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4.4.9 Quality management system A ‘quality management system’ is defined by the International Organisation for Standardisation (ISO) as the company’s structure for managing its processes or activities that transform inputs of resources into a product or service which meets the company’s objectives, such as satisfying the customer’s quality requirements, complying with regulations or meeting environmental objectives. A quality management system within food businesses usually has a wider scope than food safety and covers all quality elements. The system elements can be separated into two different groups:

r r

Quality control, that is operational requirements (product realisation, measurements etc.) that eliminate causes of loss of quality. Quality assurance, that is managerial requirements (management responsibility, resource management etc.) that provide internal and external confidence in the company’s quality management.

4.5 HAZARD ANALYSIS CRITICAL CONTROL POINTS The HACCP concept was developed in the 1950s by the National Aeronautics and Space Administration (NASA) in order to guarantee that food used in the US space programme would be completely free of microbial pathogens. HACCP was then identified by the United States Department of Agriculture, Food Safety and Inspection Service (FSIS) as a tool to prevent or control microbial safety hazards during meat and poultry production. The HACCP concept has now become a valuable programme for process control of all food safety hazards, not only microbiological ones. It has been legitimised by the Codex Alimentarius. Commission which incorporated the HACCP guidelines into the food hygiene code (CAC/RCP1) as an annex HACCP system allows each company to identify and control the hazards specific to its activities.

4.5.1 Food safety management systems A food safety management system is the policy, structure and procedure implemented by the company to express its concern and involvement in food safety. It is the application of a quality management system within the area of food safety. The implementation of good practice (often named ‘prerequisite programmes’) is a minimum requirement of a food safety management system, but it is not sufficient in itself. Generally, standards on food safety management systems demand the additional implementation of procedures allowing the identification and the control of the hazards specific to the company, most of the time on the basis of the principles of the HACCP.

4.5.2 Private and national food safety standards A key concern of private operators is for their reputation. The assurance of the safety and quality of the food supply is traditionally a prerogative of governments through the development of regulations and inspections. However, following a number of global food safety incidents during the 1990s, consumer confidence in the capacity of regulators to guarantee food safety has declined in many

National and international food safety certification schemes Table 4.1

89

Market share for all private label products (top ten).

Country

Retail brand share (%)

Switzerland Great Britain Germany Belgium Spain France Canada Netherlands United States Denmark

38 31 27 24 23 21 20 19 15 13

Source: ACNielsen (2003). The power of private label, a review of growth trends around the world.

parts of the world including Europe. In response, the private sector has moved to implement more and more specific standards with higher requirements than regulations in order to ensure the quality, safety and traceability of their products and processes. This concern of private operators for food safety is linked to their responsibility to put safe products in the market; responsibility usually granted by regulatory provisions (for instance by the Regulation (EC) 178/2002 in the European Union). It is also accentuated by economic concerns linked to customer hypersensitivity to food safety, as a negative incident can have disastrous economic consequences for both brand producers and retailers. Although food safety standards can be established by public bodies, most of these are private standards developed by private operators themselves. Furthermore, most of these standards are business-to-business standards that seek to demonstrate the safety and quality of products or services produced by a supplier or sub-contractor to a buyer, without any communication to consumers (by means of a label for instance). As the final link in the food chain, which is in direct contact with consumers, retailers are generally the first to be concerned if a food safety incident affects consumers. This responsibility of retailers is naturally greatest on their private label products, since they are directly responsible for the safety of the products they make. This is all the more true as the market share for private label products is increasing especially in Europe (see Table 4.1). Certification clearly defines the responsibilities of each party (supplier, buyer), which is a growing concern for private operators since the food safety crises of the 1990s. The increasing use of certification, buoyed by the proliferation of standards, especially in the food safety field, has thus created a real industry in itself, with a high level of competition between auditors.

4.5.3

Increasing power of retailers in industrialised countries

Since the 1990s, the power in the food sector in developed and emerging economies has shifted from manufacturers and producers to retailers (OECD, 2004, private standards and the shaping of the agro-food system). This shift is mainly due to two factors: – Increased retail market concentration; and – Increased market share of private label products.

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Sales share of the five largest retailers in selected countries.

Country

Concentration ratios (%)

Austria Belgium/Luxembourg Denmark Finland France Germany Greece Ireland Italy Netherlands Portugal Spain Sweden United Kingdom

60 61 56 68 56 44 27 58 18 56 63 40 78 63

Source: OECD (2004) from the CIR European Retail Handbook and trade sources.

4.5.4

Retail concentration

Retailing is currently carried out by a small number of firms in many countries, especially in industrialised countries, due to numerous mergers and acquisitions during the last 20 years. Many retailers have also become multinational so that global food retailing is increasingly composed of a limited number of multinationals (see Table 4.2).

4.5.5 Certification programmes for complete food safety management systems Some certification programmes (see Table 4.3) establish requirements for quality management systems (including an HACCP system), as well as specific requirements for good practice (GAPs or GMPs), as these programmes are the most complete. However, they usually apply to a specific step of the food chain (primary producers or manufacturers).

4.6 THE GLOBAL FOOD SAFETY INITIATIVE The Global Food Safety Initiative (GFSI) was launched by food retailers in response to the proliferation of diverse standards. GFSI is a food retail initiative created in May 2000 by the Global Food Business Forum (CIES), a network of 175 retailers and 175 suppliers in more than 150 countries, representing 65% of global food retail revenue. GFSI aims to ensure that existing worldwide food safety standards are pertinent and reliable. Specifically, it implements and maintains a scheme to benchmark food safety standards (for private label products) as well as farm assurance standards, by facilitating mutual recognition between standard owners and by ensuring worldwide integrity in the quality and the accreditation of food safety auditors. The GFSI Guidance Document establishes a benchmark model to serve as an ‘equivalence framework’. It outlines key elements that a food safety standard should contain:

National and international food safety certification schemes Table 4.3

91

Examples of certification programmes for complete food safety management systems.

Country

Standard

Target

Standard-setting body

Status of the standard-setting body

Germany/France International food standard

Food manufacturers

Hauptverband des Deutschen Einzelhandels/ F´ed´eration des entreprises du Commerce et de la Distribution

Association of food retailers

New Zealand

Approved supplier programme

Fruit and vegetables producers

Vegetable & potato growers’ federation/ New Zealand Fruit growers federation

Association of primary producers

United Kingdom

BRC global standard for food safety

Food manufacturers

BRC

Association of food retailers

United States

CertiClean

Food manufacturers

Scientific certification systems

Private certification body

Source: From the internet research. BRC, British Retail Consortium.

r r r

Good agricultural or manufacturing practices; A quality management system applied to food safety (e.g. based on the ISO 9000 series); and An HACCP-based system in accordance with, or equivalent to, the Codex standard.

The requirements of this benchmark model are flexible, given the variations within the standards. For instance, GlobalGAP does not require a HACCP system, while neither SQF nor the Dutch HACCP Code establishes specified good practice. Nevertheless, a standard approved by GFSI should theoretically be recognised by all retailers around the world.

4.6.1

Benchmarked standards

The following standards have GFSI recognition:

r r r r

SQF standard ◦ SQF 2000: for manufactured products ◦ SQF 1000: for primary (farm) production IFS BRC global standards Dutch HACCP

Source: Global Food Business Forum (CIES) web site (available at: www.ciesnet.com). Despite GFSI approval, these standards are not always mutually recognised. For instance, a number of European retailers continue to demand BRC or IFS certification exclusively even if the supplier is certified to another GFSI-approved standard and even though the two standards are very similar.

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Table 4.4

The key elements showing similarities and differences among key global certification schemes. BRC global standard for food safety

IFS

SQF

Dutch HACCP Code

ISO 22000

Countries

British market, Scandinavian markets to a less extent and increasingly, internationally

Essentially German and French market and increasingly, internationally

American and Australian market primarily

Dutch market primarily

International

Users

Food manufacturers (originally for private label products, but increasingly also for branded products)

Food manufacturers (originally for private label products, but increasingly also for branded products)

SQF1000: food primary producers

All companies handling food (although primary producers not explicitly mentioned)

All companies handling food (including primary producers)

SQF 2000: food industries Scope of standard

Quality management system, HACCP system, GMPs

Quality management system, HACCP system, GMPs

Quality management system

Quality management system, HACCP system

Quality management system, HACCP system

Stakeholders – required by

Majority of UK retailers require BRC certification from all their suppliers for their private label products

Majority of French and German retailers require IFS certification from all their suppliers for their private label products

A number of American and Australian retailers recognise SQF certification, but they do not seem to require it automatically

Dutch retailers primarily

Acceptance by retailers and producers cannot yet be assessed accurately

Source: From the internet research. GMPs, good manufacturing practices; HACCP, hazard analysis and critical control point; SQF, safe quality food.

4.6.2 Major certification programmes based on food safety The certification programmes discussed here have all been benchmarked by the GFSI. A comparison of the key elements of the major global certification programmes for food safety is provided in Table 4.4.

4.6.3 BRC global standards The BRC is the leading trade association for UK retailing. There are three types of members: – Retail members (including Tesco, Marks & Spencer and Sainsbury’s), who represent the majority of retailers (approximately 80–90%) in the United Kingdom; – Trade association members; and

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– Associate members (that is services to the retail industry including accountants, consultants or financial services) who do not participate in the decision-making process. The BRC set up the food standard in 1998 in response to industry needs. In view of the success and widespread acceptance of this standard, the BRC also published a packaging standard in 2003, a non-food products safety standard in 2003, and then a non-genetically modified food assurance in collaboration with the British Food and Drink Federation.

Scope and objectives The global standards now consist of a suite of four standards which are an enhancement to the original BRC standard which was designed to comprehensively meet the needs of retailers who sub-contract manufacturing of their own-brand goods. The BRC certification is product and site specific and covers the following:

r r r r

Food manufacture; Manufacture of packaging; Manufacture of consumer products; and Storage and distribution activities.

Originally developed by UK retailers, the BRC global standard for food safety helped brand owners satisfy their legal responsibility for products under the Food Safety Act of 1990. Now recognised worldwide with more than 10 000 certificated food companies, it demonstrates products are produced to a minimum standard. The requirement for suppliers to be certificated to the BRC’s three other standards is also increasing.

4.6.4 The BRC global standard for food safety Provisions of the standard Now, the global standard for food safety has seven sections and requires the development of and compliance with the following:

r r r r

Senior management commitment: The resources required for demonstration of commitment to achieve the requirements of the standard. A HACCP plan: This provides a focus on the significant product and process food safety hazards that require specific control to assure the safety of individual food products or lines. A quality management system: Details of the organizational and management policies and procedures that provide a framework by which an organization will achieve the requirements in the standard. Prerequisite programmes: The basic environmental and operational conditions in a food business that are necessary for the production of safe food. These control generic hazards covering good manufacturing and good hygienic practices.

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Updates to the standard The new edition of the standard, the global standard for food safety, was published on 4 January 2008. Incorporating a thorough review of all clauses to provide greater guidance for food businesses and clarity to auditors, the standard has been extensively revised from issue 4. A summary of key requirements includes the following.

Grading scheme A rigorous grading scheme for grades B, C and D has been introduced with a revisit by the certification body required within 28 days to verify corrective actions for Grade C as well as audit frequency reduced to 6 months.

Optional unannounced audits These are now available for companies gaining grade A or B audit score at announced audits. A successful unannounced audit results in the awarding of an * against the resulting A, B or C grade. The BRC standards not only deal with quality management systems and HACCP but also establish general GMPs for food safety. The BRC global standard for food safety establishes some requirements that are outside the scope of the Codex Code of Practice on General Principles of Food Hygiene. Specifically, these include not only those dealing with quality control issues (such as handling of non-conforming products, management of the monitoring system, traceability, management of allergens, and quantity control) but also some on food safety good practices (such as maintenance of external areas).

Market penetration The global standard for food safety was originally developed by British retailers and dedicated to their manufacturing suppliers for their private label products in order to ensure food safety at all levels of the manufacturing supply chain for their private label goods. The standard is increasingly being considered as a benchmark for best practice. Many retailers now demand BRC certification from manufacturers of branded products as well as own-brand products. In addition, some other operators, including some global brand owners, now require BRC certification from their sub-contracting suppliers. According to the BRC website, the majority of British and Scandinavian retailers do business only with suppliers who have gained certification to the BRC global standard. Source: BRC website (available at: www.brc.org.uk).

4.6.5

The IFS

Provisions of the standard The requirements of the IFS cover five sections: – – – – –

Management of the quality system; Management responsibility; Resource management; Production processes; and Measurements, analyses and improvements

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Updates to the standard The IFS Version 5 became effective on 1 January 2008. Version 5 of IFS has been significantly updated from Version 4 and is now a collaboration of the three retail federations from Germany, France and Italy. Version 5 shows increased emphasis on specifications, agreed recipes, handling of non-conforming products, and food safety of packaging material and production equipment. It features:

r r r r r r

One checklist, there is no more distinction between foundation and higher level requirements; No more requirements with respect to recommendation(s); More requirements aligned to a risk analysis approach and more emphasis on processes and procedures; A new scoring system which allows an easier comparison of results and also gives better transparency between the audited companies; Change of the audit frequency to a 12-month cycle; determination with more knockout (KO) requirements with a focus on food safety; and More detailed requirements for accreditation bodies, certification bodies and auditors.

Like the BRC standard, IFS establishes a certain number of requirements that are not in the Codex Code of Practice on General Principles of Food Hygiene, with regard to quality control (handling of non-conforming products, management of the monitoring system, traceability, management of allergens etc.) and food safety good practice (maintenance of external areas).

Market penetration According to IFS, almost all German and French retailers ask for IFS certification. However, some major retailers do not support IFS. Among the supporting retailers, some ask all their subsidiaries around the world for IFS. Retailers in several other countries (such as Austria, Poland, Switzerland, and Italy) also request IFS certification. At present, such retailers ask for IFS certification only from the producers of their private label products and do not require it from branded product suppliers. However, according to the IFS, it appears that many branded product companies perform IFS audits of their own companies and ask their sub-contractors and suppliers to do the same.

4.6.6 The SQF standards The SQF standards were originally established by the Western Australian Department of Agriculture in 1996, in response to the demands of the farming and small food-manufacturing sectors for a quality assurance system that enabled their businesses to meet regulatory food safety and commercial food quality criteria. As no suitable system could be identified, the Western Australia government established the SQF Quality Code. After its creation, the SQF standard caught the attention of the Food Marketing Institute (FMI), an American retail association, and worldwide ownership of the standards was transferred to the FMI in 2003. The SQF Institute, a division established by the FMI, now manages the SQF programme. The FMI comprises 1500 US or international member companies (both food retailers and wholesalers). The US members (in particular Wal-Mart and Kroger) operate approximately 26 000 retail food stores with a combined annual sales volume of $340 billion, that is three quarters of all

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food retail sales in the United States. The international membership includes 200 companies (in particular, Carrefour, Ahold and Tesco) from 50 countries.

Scope and objectives The SQF programme is intended to deal with complete food safety management systems; however, in comparison to the BRC or IFS standards, it only specifies requirements on quality management systems and does not specify good practice nor HACCP plans (though it demands them). It is designed for all types of food products and for all types of suppliers (the SQF 1000 Code for primary producers, the SQF 2000 Code for food industries).

Certification programmes Two certification programmes have been established for different types of food product suppliers:

r r

SQF 1000: This standard, currently in its third version, is specific to primary producers and to issues of concern to them (pre-farm gate production, harvesting, preparation of primary products). SQF 2000: This standard, currently in its fourth version, is specific to food industries and to issues of concern to them (raw materials and ingredients, processed or prepared foods, beverage or services).

There is no obligation for a supplier who would like to be certified SQF 2000 to receive raw materials from a certified SQF 1000 primary producer. Each programme allows for three levels of certification, which more or less correspond to the number of food safety system components that are implemented by the business: – Level 1 (Food Safety Fundamentals): This certificate assures that the company implements prerequisite programmes (good agricultural or manufacturing practices), whatever they are, and fundamental food safety controls. – Level 2 (Accredited HACCP Food Safety Plans): This certificate assures that the company implements prerequisite programmes and a food safety plan in accordance with the HACCP method. – Level 3 (Comprehensive Food Safety and Quality Management Systems Development): This certificate assures that the company implements prerequisite programmes and a food safety plan, which is based on the principles of HACCP and which prevents the incidence of poor quality. SQF requirements (for SQF 1000 as for SQF 2000) are divided into three levels, corresponding to the three different certifications. To implement level 2, producers must comply with level 1 plus additional requirements. Likewise to implement level 3, producers must comply with level 2 plus additional requirements. For each level, compliance with the provisions is obligatory without any tolerance margin. Only an ‘SQF expert’ (a member of the company or an external consultant who has been qualified by the SQF Institute) can implement SQF programmes within the company.

Provisions of the standard As the SQF standards mainly deal with quality management systems, they essentially require adequate management procedures. Interestingly, most of the provisions of the SQF codes only

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require that the company provide appropriate procedure documentation and do not explicitly require that the company implements such procedures. The SQF 1000 and SQF 2000 provisions are very similar, since they both establish identical requirements for most of the provisions. However, there are some differences between the two codes, notably: – The mentioned prerequisite programmes are noticeably GAPs in the SQF 1000 Code and GMPs in the SQF 2000 Code. No reference is made to the relevant Codex Alimentarius standards, such as the Code of Practice on General Principles of Food Hygiene. Concerning quality control, the SQF Codes do not address all issues requirements detailed by the Codex Code of Practice on General Principles of Food Hygiene (management of temperature/time, product packaging).

Market penetration Most American retailers and several global retailers support the SQF standard. However, it is not clear whether ‘support’ means ‘recognise’ or ‘require’, particularly, since some of the retailers supporting SQF also support other standards.

4.6.7

Dutch HACCP Code

The standard, also called CCvD-HACCP Code, was set up in 1996 by the Dutch National Board of Experts-HACCP (CCvD-HACCP), a board composed by representatives of all parties involved in the food chain (i.e. National Bureau for the Provision Trades, certification bodies, consumer associations, food production and industry).

Scope and objectives The standard focuses on all operators along the food chain (concerned with preparation, processing, manufacturing, packaging, storage, transportation, distribution, handling, offering for sale or supply), but not on suppliers or service companies to food business (such as suppliers of packaging materials, food equipment, industrial cleaning services). Primary producers are neither explicitly included in, nor excluded from, the scope of the standard. It establishes requirements for quality management systems and HACCP systems, but not for good practice.

Certification programme The third version of the normative document (requirements for an HACCP-based food safety system) was published in September 2002. For three years after the initial certification, surveillance is 6 monthly. After three years, a total reassessment is conducted; if there are no open non-conformities and no new non-conformities are revealed with the entire reassessment, then the surveillance can be annual.

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Provisions of the standard The composition of the requirements within the normative document is similar to the structure of the HACCP steps as described by the Codex Alimentarius: – – – – – – – – – – – –

Management responsibility (policy, scope, responsibilities, HACCP team etc.); Product information (product characteristics, intended use etc.); Process information (flow diagrams, layout etc.); Prerequisite programme(s); Hazard analysis; Control measures; Parameters and critical limits; Monitoring and measuring; Corrective actions; Validation; Documentation and records; and Verification.

In terms of good practice, the Dutch Code requires implementation of ‘prerequisite programmes’ but (as with the SQF Codes) does not define what such practices should be. However, the Codex Code of Practice on General Principles of Food Hygiene is explicitly described as ‘a firm foundation for ensuring food safety and suitability’ and the provisions of this Codex Code of Practice are detailed in an annex. Concerning quality control, the Dutch HACCP Code does not address several issues mentioned by the Codex Code of Practice on General Principles of Food Hygiene, notably monitoring of incoming materials, management of temperature/time and product packaging. The Dutch Code fully complies with the 12 Codex HACCP steps.

Market penetration The Dutch HACCP Code was the first HACCP-based certification programme, but it has a weaker penetration than the standards already discussed in this chapter. It only concerns the Dutch market, as it is mainly supported by Dutch retailers. Information on retailers endorsing the standard is not available. Similarly, it is not known whether the retailers endorsing the standard only recognise the standard or whether they ask all their suppliers to seek approval against this standard.

4.6.8 ISO 22000 The ISO is a network of 146 national standards bodies, one per member country, coordinated by a Central Secretariat in Geneva, Switzerland. ISO is a non-governmental organisation but occupies a special position between the public and private sectors. Many of its members are national governmental institutions or institutions mandated by a government, while other members (such as national industry associations) have their roots in the private sector. Therefore, although it is not an intergovernmental organisation, the WTO Agreement on Technical Barriers to Trade (TBT) explicitly recognises ISO as providing internationally accepted standards. Between 1947 and the present, ISO published more than 15 000 international standards. While the standards developed by the food retail sector demonstrate a certain degree of harmonisation of food safety management systems standards, several different standards, each supported by

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different global retailers, continue to exist. The objective of the ISO 22000 is precisely to establish a single internationally recognised standard for food safety management systems.

Scope and objectives ISO has established standards on quality management systems, the ISO 9000 series that has become an international reference for quality management requirements in business-to-business dealings. More than half a million organisations in more 149 countries are implementing the ISO 9000 series. However, this standard is not specific to the food industry and does not take into account food process specificities, especially in regard to food safety issues. In this context, ISO recently developed the ISO 22000 standard specifically for food safety management systems. However, the ISO 22000 standard only specifies requirements on quality management systems and HACCP systems, and not on good practice. ISO 22000 applies to all food operators (feed producers, primary producers, manufacturers, transport and storage operators, retail and food service outlets and related organisations such as producers of equipment, packaging material, cleaning agents, additives or ingredients). Thus, primary producers are included in the scope of the standard.

Provisions of the standard The layout of ISO 22000 resembles ISO 9001:2000 in order to enhance compatibility between the two standards and allow their joint implementation. The requirements are divided into six chapters covering: – Food safety management system (general requirements, documentation); – Management responsibility (management commitment, policy, management system planning, responsibility and authority, team leader, communication, emergency preparedness and response, management review); – Resource management (provisions of resources, human resources, infrastructure, work environment); – Planning and realisation of safe products (prerequisite programmes, preliminary steps to enable hazard analysis, hazard analysis, establishing the operational prerequisite programmes, establishing the HACCP plan, updating, verification planning, traceability system, control of non-conformity); and – Validation, verification and improvement (validation of control measure combinations, control of monitoring and measuring, management system verification, improvement). ISO 22000 does not provide requirements for good practice. Indeed, ISO maintains that it cannot establish such requirements because the standard is intended to be applicable to all types of organisations in the food chain (by comparison IFS and BRC caters for manufacturers and packers). It does, however, require that the company implements adequate good practice programmes (as ‘prerequisite programmes’) and makes an explicit reference to the Codex principles and codes of practices. ISO 22000 describes the various aspects that such programmes should address (construction and layout of buildings, waste and sewage disposal, cleaning, maintenance, pest control, personnel hygiene etc.), similar to the different topics of the Codex Code of Practice on General Principles of Food Hygiene. In terms of quality control, ISO 22000 (like the Dutch HACCP Code or the SQF codes) does not cover a number of issues mentioned by the Code of Practice on General Principles of Food

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Hygiene, such as monitoring of incoming materials, management of temperature/time, and finished product identification. In relation to HACCP, ISO 22000 establishes requirements that comply with the 7 Codex principles and the 12 Codex steps. ISO 22000 adds another step between hazard analysis and identification of the Critical Control Points (CCP). Indeed, ISO 22000 considers that the hazard analysis allows the identification of necessary control measures. Either such necessary control measure concerns a CCP and then is managed by subsequent HACCP classic steps, or it is not and then shall be managed by prerequisite programmes, in such case named ‘operational prerequisite programmes’, which must be documented more specifically.

Market penetration The standard was released on 30 August 2005, and data relating to market penetration are still patchy at the present time.

4.7 A COMPARISON OF MAJOR GLOBAL CERTIFICATION PROGRAMMES FOR FOOD SAFETY See Table 4.4.

4.8 SUMMARY OF COMPARISON OF GLOBAL CERTIFICATION PROGRAMMES The standards examined each have their own specific set of requirements, which makes each one unique. It is also possible to identify several common characteristics:

r r

The ISO 22000, the SQF codes and the Dutch HACCP Code make detailed requirements on quality assurance and on HACCP (except SQF), but have few requirements on quality control and none on good practice because they address all food operators. The IFS and the BRC Global Standard for Food Safety make detailed requirements on quality assurance, quality control, HACCP and GMPs. They are thus perceived as more complete and more demanding than the above group, but are dedicated only to food manufacturers. The IFS and the BRC standard are very similar, but not identical.

4.8.1 Finally – the way forward: towards standards harmonisation? Organizations that produce, manufacture, handle or supply food recognise that customers increasingly want them to demonstrate and provide adequate evidence of their ability to identify and control food safety hazards and the many conditions impacting food safety. The growing number of national standards for food safety management, however, has at times led to confusion. Consequently, many users feel that there is a need to harmonise the national standards at global level. The proliferation of certification programmes in the food sector means that producers who wish to access industrialised country markets face several challenges, in particular a large number of different product specifications and audits each year. The retail sector has attempted to regulate

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food safety requirements by setting up specific standards based on their own expectations. However, this has sometimes added to the confusion, since several standards have been created, each one specific to the market of a certain country. The GFSI is currently attempting to harmonise these retail standards, but in practice, retailers continue to demand their own standard. Because standards such as the SQF codes or the Dutch HACCP Code do not establish GMPs or GHPs, it is possible that they may perhaps become less used because their requirements are more or less covered by ISO 22000 at present. The main advantage of ISO 22000 is that it applies to all stakeholders along the food supply chain, including primary producers and manufacturers, so that it may be used throughout the entire chain. The acceptance of ISO 22000 by relevant stakeholders, especially retailers, is obviously a condition of its success. Some users suggest that if ISO 22000 is recognised as a valuable management system requirement, the large overlap between standards and certification assessments may disappear. It is, however, worth noting that because ISO 22000 does not provide a detailed list of requirements for good practice and for quality control, each company may thus use its own GMPs or GHPs. Reliability of these cannot be easily judged by retailers, since these GMPs or GHPs will not necessarily appear in the ISO certification report. Retailers, therefore, do not appear to be ready to abandon their own standards. In contrast, both BRC and IFS standards do ensure the implementation of GMPs and GHPs, adapted to the needs of the appropriate retailers. Furthermore, given the nature of the ISO system, any procedures to improve or update the ISO 22000 standard is likely to be time consuming. In contrast, retailers may modify their standards more quickly. For instance, ISO 9000 is in its third version since its initial publication in 1987, whereas IFS is in its fifth version since 2002 and BRC has also published a fifth version since 1998. Therefore, it seems unlikely that ISO 22000 could take the place of either the IFS or the BRC standard in the foreseeable future. It would nevertheless seem advantageous to users of the standards to see a merger of similar standards such as the IFS and BRC in the coming years, given their similarities and the convergence of their requirements as they evolve. Whether this will occur still remains to be seen.

5

Fish quality

Tony Garthwaite

5.1 INTRODUCTION The quality of the raw material is the key factor which governs the final product quality. This applies as much to canned fish as to any other food commodity. The quality parameters of fish and shellfish used in the canning industry are well understood. Assessment of the quality parameters is possible using both organoleptic and analytical methods in the laboratory and the chemical and microbiological testing are dealt with in other sections of this book. In this section, we will consider the origins of the raw material and the standards generally considered when sourcing and buying fish and shellfish for canning.

5.2

IMPORTANT FISH SPECIES

The main fish species to be considered for canning are the oily fish listed in Table 5.1.

5.2.1

Salmon

Canned salmon comes in two basic forms: sockeye or red salmon, and chum or pink salmon. The pink salmon is less expensive, milder in taste and good for dishes where the salmon’s colour and taste is not quite as important, such as soups, casseroles and sandwich spreads. Red salmon is used for cold salads where appearance is important. Sockeye salmon are the preferred species for canning due to the rich orange-red colour of their flesh. Today, however, more than half of the sockeye salmon catch is sold frozen rather than canned. Canned sockeye salmon is marketed primarily in the United Kingdom and the United States while most frozen sockeye salmon is purchased by Japan. When smoked, Sockeye has a stronger flavour and firmer texture than Coho salmon. Sockeye salmon roe is also valuable. It is salted and marketed in Japan. Carotenoids give salmon flesh its ‘red’ colour. Carotenoids are part of a larger family of organic chemicals which includes alpha-carotene, beta-carotene, carotene and Vitamin A. Those carotenes are found in vegetables such as carrots, beets and bell peppers. The carotenoid in salmon is astaxanthin. It is an antioxidant that is ten times more powerful than other carotenoids. To be fair, wild salmons have eight times more astaxanthin than farm raised. This seems to be a nutritional and husbandry issue, not the salmon or species; however, the amount of Omega-3 fatty acids seems to be about the same. In 2003, the legal firm of Smith & Lowney instigated, for their clients, a lawsuit for the improper labelling of salmon against three corporate supermarket chains. Technically, the FDA has ruled that

Fish quality Table 5.1

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Fish species used for canning.

Tuna Albacore Bigeye Yellowfin Blackfin Skipjack Longtailed (Northern bluefin) Oriental Little tunny Black skipjack Little tuna or Kawakawa

Thunnus alalunga or T. germo Thunnus obesus or Para thunnus mebachi Thunnus thynnus Thunnus atlanticus Thunnus albacares or Katsuwonus pelamis Thunnus tonggol Thunnus orientalis Euthynnus alletteratus Euthynnus lineatus Euthynnus yaito or E. affinis

Bonitos Atlantic Sarda sarda Pacific Sarda chiliensis or S. lineolata Tropical Atlantic, Pacific and Sarda orientalis Indian Oceans Amberjacks/Yellowtails

Cololabis saira

Salmon Pacific Chinook/King Chum Coho Pink/Humpback Red/Sockeye

Onchorhynchus tschawytscha Onchorhynchus keta Onchorhynchus kisutch Onchorhynchus gorbuscha Onchorhynchus nerka

Mackerel Atlantic Chub Mackerel/Pacific Herring Atlantic Herring Pacific Sprats Pilchards Europe/Atlantic Californian Pilchard Chilean Pilchard Japanese Pilchard South African Pilchard Anchovy Atlantic N. Pacific Anchovy S. Pacific Anchovy Japanese Anchovy

Scomber scombrus Scomber japonicus Clupea harengus Clupea pallasii Sprattus sprattus Sardina pilchardus Sardinops caerulea Sardinops sagax Sardinops melanostica Sardinops ocellata Engraulis encrasicholus Engraulis mordax Engraulis ringens Engraulis japonica

Sardines Mediterranean, Atlantic Pacific sardine Japanese pilchard Picton herring/(Australia)

Sardina pilchardus Sardinops caerulea Sardinops melanostica Sardinops neopilchardus

Atlantic saury Saury pike Brisling (Scandinavian) Sild (Scandinavian)

Scomberesox saurus Scomberesox forsteri Sprattus sprattus Clupea harengus

astaxanthin is a colour additive. As such, although astaxanthin works as a powerful antioxidant, because it provides colour to ‘food stuffs’ it is to be labelled as a ‘colour additive’. Chinooks are the largest and the top-of-the-line among Pacific salmon. They are also called Kings. Chinooks have characteristic black lips. Chinooks are harvested from March to October from central California to the Yukon River in Alaska and in Canada, primarily by trawlers but also

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by seiners and gill-netters. Canneries are able to purchase salmon in pristine condition, fresh from the fishing boat. Omega-3 fatty acids protect against heart disease, in part by lowering blood pressure and reducing triglyceride levels. Fish is the primary source of omega-3 fatty acids in our diets.

5.2.2

Shellfish

Shellfish including molluscs and crustaceans as well as fish roe are also preserved by thermal processing in cans or glass jars. Some of these are listed in the following table: Scallops Squid Cockles Mussels Shrimp Oysters

5.3 5.3.1

Clams Crab Lobster Caviar Cod roe

POLLUTION ASPECTS General

Toxic chemicals that contaminate fish have been, and continue to be, put into our environment from manufacturing, agricultural and energy-generating activities. Coal-burning power plants release mercury into the air, and it falls into our waterways. Pesticides, such as DDT and chlordane, travel far and wide on air and water currents. Many of these contaminants persist in the environment for years. It is the same from ancient Mediterranean towns to big city docks in Asia, America’s Gulf ports or harbours in seemingly pristine Arctic waters. Industrial waste permeates every ocean. When fish live in polluted waters, they absorb and consume the chemicals in the water, thereby becoming contaminated themselves. As a result, some fish are not healthy to eat and other fish should be eaten only in moderation. Pollution of fish and shellfish stocks is directly linked to nutrients or fertilisers carried down by rivers. The rivers carry water supplies contaminated by sewage, industrial waste and agricultural runoff that may include pesticides. Molluscs such as mussels thrive in estuarine waters where there is a plentiful supply of food and during the feeding process; they accumulate pollutants such as heavy metals. Where not controlled, fish farms may discharge water which has not been decontaminated into the river systems which, in turn, further pollutes the water supply. Also, the waste produced by salmon farms and pumped into the sea contains large quantities of ammonia, which can cause Amnesic shellfish poisoning (ASP). ASP is caused by consumption of shellfish that contain the marine toxin, domoic acid. The toxin is concentrated in filter feeding shellfish including clams, oysters and scallops. The domoic acid acts as a neurotoxin, causing permanent short-term memory loss, brain damage and death in severe cases. Freezing or cooking very affected fish or shellfish tissue will not lessen the toxicity. Consequently raw material should be sourced from waters where the dinoflagellate which produces the toxin is known to be absent. Although rich in omega-3 fatty acids vital to the heart and brain, many fish contain toxins that build up over time in the human body. Besides mercury, which can damage the brains of foetuses and young children and can affect healthy adults, there are PCBs, dioxins with unknown long-term effects.

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Chemical contaminants of concern in seafood include:

r r r r

Polychlorinated biphenyls (PCBs); Polybrominated diphenyl ethers; Dioxins; and Pesticides, such as DDT and chlordane.

These chemicals, known as persistent organic pollutants, can take years – even decades – to break down and dissipate. Seafoods of greatest concern are the following:

r r r

Predatory and large fish (tuna, shark, swordfish, salmon etc.): These fish tend to accumulate high concentrations of contaminants because they eat large quantities of other contaminated fish over a long life span. By the time predatory fish get large, they have swallowed a lot of toxins. Bottom feeders (lobsters, molluscs etc.): Pollutants tend to settle on the bottom of waterways, where these creatures spend most of their lives. Toxins are unlikely to be washed away or biodegrade because of lack of sunlight. Fatty fish (tuna, mackerel, salmon etc.): Some contaminants are stored in fat, so fish and seafood with high fat content are more likely to be contaminated at unhealthy levels.

In certain species of fish – especially shark, swordfish and king mackerel – mercury content is at levels which can be harmful, especially if consumed by pregnant women and young children. High levels of mercury can damage the developing brain of a foetus or child. Though tuna is safe to eat, mercury levels are higher in tuna steaks and canned albacore tuna compared with canned ‘light’ tuna. Large Albacore caught in the South Pacific for the large canneries usually weigh 20–30 kg and their mercury level averages around 0.36 ppm. Troll-caught albacore harvested from waters off the coasts of California, Oregon and Washington are smaller – 5 to 10 kg – and average only 0.14 ppm of mercury, well below the present limit of 1 ppm accepted generally at this point in time.

5.3.2

Ciguatera toxin

Ciguatera toxin is a type of seafood poisoning caused by the consumption of fish, especially certain tropical reef fish, which contain one or more naturally occurring neurotoxins from the family of ciguatoxins and maititoxins. Repetitive handling or processing of ciguatoxic fish organs may also lead to Ciguatera poisoning. There are reports that cleaning of ciguatoxic fish may cause tingling of the hands, indicating that ciguatoxins may be absorbed through the skin. Ciguatera poisoning is considered to be the most common form of sea food poisoning in the world with the estimated number of cases ranging from 50 000 to 1 000 000 annually. Mortality is in the region of 10% but may in isolated cases be as high as 20%, though in the case in point, it was due to eating shark and occurred in Madagascar. The two most popular types of canned tuna – white and light – vary greatly in their average mercury content. Canned white tuna consists of albacore, a large species of tuna that accumulates moderate amounts of mercury. Canned light tuna usually consists of skipjack, a smaller species with approximately one-third the mercury levels of albacore. Yellowfin tuna, a species that is similar in size and mercury content to albacore, has been known to be incorporated into light tuna packs. Farmed fish may seem like a safer alternative, but that is not always the case. Because farmed fish are raised in close quarters, they must be treated with pesticides and fed antibiotics to minimise

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lice and disease. In some cases, farming can contribute to environmental pollution of waterways due to waste and pesticides. Salmon is particularly problematic when farmed. Farmed salmon are fed a fishmeal diet that tends to increase the concentration of contaminants in the fish. They have been shown to have higher concentrations of pollutants – up to ten times more PCBs – than their wild counterparts.

5.4 HANDLING AND TRANSPORT When we consider the term canned fish, we must include both fish and shellfish as raw material which may be used to fill the container. By far the greater percentage of a fish which is canned is caught by fishing vessels and which hunt for their catch in waters where the desired species are known to congregate in large numbers at certain times of the year. Because many of these catches are seasonal, species which are caught in excess of the capacity of the canneries must be preserved by other methods for use at a later date. The handling of the fish from the point of capture to the reception at the cannery, when carried out correctly, will result in the cannery producing a product of excellent quality. However, poor handling of the catch may result in rejection of the fish at the cannery door. Air blast, spray brine and brine immersion and shelf freezers are commonly used to freeze top quality albacore. Each has good and bad points from the standpoint of people working in the fishing industry, but all can and do produce good-quality frozen fish. Freezing systems using salt brine (spray and immersion) rely on the fact that strong salt brine will not freeze unless its temperature is below −18◦ C. Tuna properly exposed to this cold brine will freeze so fast that very little salt is absorbed into the flesh. However, if the temperature of the brine is not cold enough, the tuna will absorb salt from the brine and acquire a salty taste. Overloading the system is usually the cause of this problem. Tuna held for weeks or months at temperatures above −12◦ C can develop severe quality problems making them unfit for canning.

5.5 SPOILAGE FACTORS 5.5.1

Rancidity development

Fresh fish and shellfish are very susceptible to spoilage and as a consequence may be expected to undergo some degree of deterioration between catching and delivery to the cannery reception area. The deterioration is caused mainly by enzymic reactions in the fish tissues due to autolysis, which begins as soon as the fish dies, and also due to an increase in the number of bacteria present in or on the surface of the fish if they are allowed to multiply. Physical damage due to mishandling the catch, both during netting operations and also after depositing on the deck or on dry land, may also affect quality. Mishandling may result in bruising and temperature abuse, and the rise in temperature or holding at warmer temperatures will increase the rate of spoilage. In the case of fatty fish, the availability of oxygen over prolonged periods will result in the development of rancidity to a point where the fish becomes unacceptable for further processing. Fatty fish contain high levels of unsaturated fatty acids, which are susceptible to attack by atmospheric oxygen leading to rancidity. Hence, fatty fish, such as sardines, and mackerel always have a shorter storage life than lean fish, even in the frozen state (Slabjy and True, 1978). Rancid flavours range from that of a mild cod liver oil to an acrid burning taste which is objectionable. Rancidity development in frozen fatty fish is difficult to control. The rate of lipid

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oxidation is influenced by several factors which have been described in detail by Hardly et al. (1979), Labuza (1970) and Labuza et al. (1970). Higher rates of oxidation occur with increased:

r r r r

Concentration of unsaturated fatty acids present; Access of oxygen to the fish flesh; Temperature of storage; and Exposure to light.

The reactions leading to rancidity development are also catalysed by the presence of haematin compounds and transition metals. In addition, the water activity of the fish flesh influences rancidity development. The salt and moisture content of the fish flesh can also have an effect. For example, according to Borgstrom (1965), it is generally recognised that the practice of freezing in common salt brine contributes to rancid flavours on frozen storage of fatty fish. Aitken et al. (1982) also state that the salt absorbed during brine freezing can accelerate deterioration in cold storage. Where fatty fish are to be frozen this should take place as soon as possible after capture. Research on Indian sardines frozen quickly and stored at −23◦ C found that they remained in an acceptable condition for 20 weeks. However, similar fish held in ice for three days prior to freezing were found to be unacceptable after only two weeks’ frozen storage (Shenoy and Pillai, 1971).

5.5.2 Effect of temperature The relationship between temperature and spoilage rate due to enzymes and microorganisms is well known and much work has been done relating the storage/spoilage of fish caught in colder waters to the storage temperature and time. Work on tropical species is less available but in both cases it is known that by reducing the temperature of the stored fish, the spoilage rates may be greatly reduced. The process of rigor mortis is also enzymic in origin, and results from the enzymes involved in maintaining the muscle in a state of relaxation ceasing to work. The muscle contracts and the fish becomes stiff. If the fish is whole, the skeleton will prevent any shortening. However, if the fillet has been removed from the bone, shortening will occur. The time taken for rigor to commence depends upon a number of factors:

r r

Poor condition, exhaustion and high temperatures cause rapid onset of rigor; and Well fed, quick catching and low temperatures delay the onset of rigor.

It is best to keep the fish cool because at higher temperatures the muscle contraction during rigor may be so strong that the flesh tears, resulting in a ragged fillet when finally processed. It is better to freeze a whole fish before they go into rigor when freezing at sea. It is also important that the fish is kept as cool as possible while still waiting to be processed into the frozen state.

5.5.3

Histamine

Histamine is a toxin produced by bacteria in fatty fish which have not been kept under chilled storage near the temperature of melting ice or for an extended period of time. Most of the bacteria identified as histamine formers in tuna fish destined for canning are gram negative, nearly all

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of which belong to the Enterobacteriaceae family notably Morganella morganii. Other powerful histamine-producing bacteria are Klebsiella oxytoca, Klebsiella pneumoniae and some strains of Enterobacter cloacae and Enterobacter aerogenes. Most of these species might be expected to be found as a result of contamination of fish during capture and subsequent unhygienic handling in the canning plant (Taylor, 1986; Taylor et al., 2007; Warne et al., 1987). An increase in histamine content in tuna meat was not expected through the canning process. Maximum allowable levels of histamine in fish products are fixed by both the European Economic Community and the Food and Drug Administration as well as other legislative bodies. Cannery Quality Assurance Specifications usually set maximum limits well below those set by the legislative bodies. In the case of tuna, an example of legislative standards in 2009 would state that the histamine content shall be less than 100 ppm for one sample, and the combined value of two samples shall not exceed 200 ppm. In practice, the levels expected from the analysis of brine frozen tuna at the Cannery would be in the region of <20 ppm. This figure is considerably lower than the upper limits in the legislation (L´opez-Sabater, 1994).

5.5.4

Protection in transportation by chilling and freezing

In practice it is normal to reduce the temperature of storage of fresh fish to temperatures approaching 0◦ C. This may be achieved by using ice or a combination of ice and water or refrigerated sea water (RSW). The ice acts as a heat sink, absorbing heat from the fish and its surroundings and bringing the temperature of the fish down to that of the melting ice (0◦ C). The fish must be correctly packed with the ice. It is important that the ice be placed below and above the fish in order to achieve a reasonable rate of heat transfer which results in rapid cooling of the catch. Where shoaling fish are caught in large quantities, the time taken to ice the catch adequately may be excessive and in such cases it is usual for the fish to be intimately mixed with refrigerated or chilled sea water at a temperature between −1 and 0◦ C. This has the effect of rapidly cooling the fish immediately after its capture. The fish is held in tanks on board the fishing vessel from which they may be pumped or brailed ashore. Many shoaling fish destined for use by canneries are frozen at sea. Here they may be packed into vertical plate freezers and may be frozen in a polythene bag to which clean sea water has been added (see Figure 5.1). The addition of the water both improves the rate of freezing and acts as a protection during subsequent storage reducing the risk of freezerburn. Tuna fisheries use catching vessels which have freezing facilities utilising brine in large tanks. These vessels may use purse seine nets to catch large quantities which are brailed into the freezing tanks. The temperature of the brine is in the region of −14◦ C and the fish are kept in the tanks either in the brine or in the tank with the brine drained out until transfer to shore or to a transport vessel with refrigerated holds. Where the fish is held in a drained tank, brine is re-introduced to separate fish which have become ‘welded’ together. The upper fish float off as seen in Figure 5.2 and the brine is separated from the fish as the mixture passes over a dewatering grid. The temperature of the fish is about −12◦ C as it leaves the brine. This is well above the recommended temperature for storage and transportation of frozen fish, but is at present (2009) an accepted practice for fish intended for canning. The frozen fish may be transferred to a reefer vessel (Figure 5.3) for the journey to the cannery. This will normally reduce the cargo temperature as the refrigeration system in the hold will operate at a temperature of about −20◦ C. However the final discharge temperature will depend on the length of the voyage and the time the fish is in the hold. Generally, the cannery will be happy to accept the fish at −12◦ C for storage in its cold store where the temperature will be brought down to below −18◦ C to meet the requirements of the International Legislation.

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Fig. 5.1 Vertical plate freezer showing frozen blocks in raised (discharge) position. (Photo courtesy of Tony Garthwaite.)

Fig. 5.2 Skipjack tuna being discharged from the brine tank and the brine being separated from the fish as it passes over a grid. (Photo courtesy of Tony Garthwaite.)

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Fig. 5.3

Transferring to refrigerated hold on Reefer vessel. (Photo courtesy of Tony Garthwaite.)

Ice is cheap, harmless and portable, having a very large cooling effect for a given weight and allows rapid cooling through intimate contact between the fish and ice. This ensures that the fish are kept moist, preventing them from drying on the surface. In tropical climates the quantity of ice required to cool the fish and keep it cool until landing is considerably greater than the requirements in cooler climates. With the use of ice there is always a danger that the fishermen put too much fish and ice in a box. Stacking such boxes, one box on top of another, results in boxes resting on the ice at the top of the box below, rather than resting on the walls of the box. This may produce a bruising of the fish due to pressure which may be considerable when the boxes are stacked six or ten boxes high in the hold of the fishing vessel. Studies in tropical climates have shown that for such conditions the general rule of 50% fish to 50% ice is sometimes inadequate and the use of higher proportions results in higher cost for ice. The use of dry ice as an aid to transportation of fish in ice continues to be studied practically. Although it has no harmful effects on the fish, when it is placed too close or in direct contact with the fish it will cause the fish to freeze, which may result in a loss of quality. While carrying out studies in the use of dry ice in fish handling (Putro and Wutti-jumnong, 1989) concluded that the incorporation of dry ice could significantly reduce the amount of ice used to 1:4:0.2 (ice:fish:dry ice). Consequently, the cooling efficiency of ice, as well as the amount of fish transported in a given volume, was improved. The study showed that the temperatures at the thermal centres were significantly lower using dry ice in conjunction with ice than by using ice alone. The use of dry ice

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for the chilling/transportation of shrimp was found to be more effective than for fish such as milk fish (250 g) and skipjack tuna (3.5–5.0 kg), though in all cases there was a significant improvement in the quality of the raw material when compared with samples using ice only as the chilling medium. Where fish or shellfish are to be moved from the point of capture to the cannery for processing they should be transported as quickly as possible and under conditions which are as cool as possible. Obviously, where the raw material is in a frozen state it should be transported in refrigerated containers or holds which should have a maximum temperature of −20◦ C, or in refrigerated transport where the same maximum temperature applies. The maximum recommended storage temperature for frozen fish is −30◦ C. This is often not achieved in cold stores in the tropics and is due to lack of insulation in the store, coupled with insufficient capacity of the refrigeration plant. Where refrigerated transport vehicles used in tropical countries have been imported second-hand from cooler climates, the insulation of the box and the capacity of the refrigeration compressor are often not capable of coping with the ambient temperatures in the tropics which may be 20◦ C greater than those for which the refrigeration system was designed. With such vehicles there is a danger that the temperature of the frozen product will rise during transportation. Subsequent cooling would result in a re-crystallisation of the ice causing textural problems and drip loss during further processing.

5.6 RECEPTION AND TESTING When batches of fish are received at the factory, their physical and chemical attributes should be checked against those laid down in the buying specifications. Before off-loading from the transport the temperature of the fish at various positions in the load should be checked to ensure it is below the maximum stipulated in the specification. Typical temperatures of 0◦ C for fresh fish and −18◦ C for frozen fish are ideal for acceptance in the plant. However, in the case of freshly caught fish and shellfish the maximum temperature may be set somewhat higher dependent upon the circumstances prevailing with that particular species and the catching and freezing technique. Once the temperature of the load has been checked and is within acceptable limits, the priority is to off-load the fish into chilled or cold (frozen) storage as rapidly as possible. At this point it is best to separate species and size grade, where such an operation has not already been carried out. With fresh fish and shellfish, a visual check for quality should be made during the off-loading procedure in order to check consistency throughout the load. The separate species and grades should be held in separate containers, labelled with information identifying species, size, origin and date of intake. The information required for traceability may be incorporated in a bar code system or wireless tag. RFID tags with embedded temperature sensors may be used to monitor shipments of fish during transport and storage. The off-loading procedure also allows a visual check for quality to be made. Table 5.2 is a typical example of grading systems used for salmon. The importance of such visual checks cannot be overemphasised and should be supervised by an experienced Quality Assurance Officer or operative. This is usual when unloading frozen fish from Reefer vessels discharging at the port. When taking delivery of frozen fish in containers this is not normally possible. However, checks on correct packaging and lack of damage to packaging may be made at this time. Damaged packaging usually results in some degree of freezerburn during frozen storage and its associated reduction in quality of the raw material. When the raw material is in cold storage further checks can be undertaken. The sexual maturity of salmon must be assessed as the change in preparation for breeding affects the eating quality. Konagaya (1983) suggests an increased protease activity in the muscle of chum

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Table 5.2 Quality grades for Pacific salmon grades based on the number and seriousness of defects in external appearance. Characteristics

Premium grade no. 1

Standard grade no. 2

Utility grade no. 3

Skin colour

Typical for sea run fish; good sheen, good contrast between dark dorsal and light ventral surfaces, no watermarks, no belly burn.

Some dulling of colour and sheen; line between dark dorsal and light ventral surfaces less distinct; moderate cherry belly permitted

May be very dull; and may be little distinction between dark dorsal and light ventral surfaces; cherry belly and watermarks may be extreme

Slime

Clear

Dull and cloudy

Thick, dull and copious

Net marks

No indentation, no skin perforation

May have slight to moderate indentation

May have moderate to heavy indentation; skin may be perforated

Scars

None except small, well-heeled scars

Well-heeled scars permitted

Scars permitted

Cuts or punctures

No cuts or punctures

Small cuts and punctures permitted

Cuts and punctures permitted

Scales

Nil to slight scale lost; and not more than 25% lost

Can have moderate to heavy scale loss; can have 25–75% lost

Can have total loss of scales

Fins

Must not lose more than 75% of caudal fin

Fin loss or mutilation permitted

Fin loss or mutilation permitted

Eyes

Bright and clear; should protrude

Dull

Milky or cloudy, sunken

Gills

Normal appearance; bright red to pink, free of slime

Pink to grey

Grey to greenish; slimy

Belly cavity colour (if dressed)

Fresh colour typical for species

Slight fading of natural colour; may have slightly dark discolouration from viscera

Noticeable loss of natural colour; dark discolouration from viscera may be moderate to extreme

Bruising

No bruises

No more than one small bruise

Bruises permit

Belly burn

No belly burn; no protruding ribs

May have slight to moderate belly burn; less than 10% of ribs protruding

Belly burn can be moderate to serious; protruding ribs permitted

Cuts or tears

Not more than 2.5 cm total length of cuts or tears

Not more than 5 cm total length of cuts or tears

Cuts and tears permitted

Cleaning

Thorough; no oesophagus, gills, viscera, kidney or blood remain

Thorough; no oesophagus, gills, viscera, kidney or blood remain traces of blood permitted

Traces of blood and kidney permitted

Odour

Fresh odour; no abnormal odour

Loss of fresh odour; no sour or abnormal odour

May have slight off odour, but no trace of decomposition

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salmon during spawning migration. This causes softening of the muscle tissue. However, Yamashita and Konagaya (1991a, 1991b) state that it is probable that it is the participation of phagocytes rich in cathepsins which cause the extensive muscle softening of the mature salmon. Farmed salmon are fed a diet rich in carotenoids to produce the red colour favoured by the consumer. Diets may also contain antibiotics, considered necessary in intensive farming, though carry-over of residues should be avoided in fish destined for use in canning. Herring, salmon and other fish, such as sturgeon, are processed to remove the roe for canning. Systems exist for sorting fish in order to separate the roe bearing females from the milt bearing males. Such systems operate by using infrared light at a particular frequency. Once sorted, a machine such as an automated roe herring opener, manufactured by Neptune Dynamics Ltd., opens each fish and removes the cured roe skeins from the fish without damage to the roe. These machines operate at speeds much faster than processing each fish individually by hand. The machines are used on mixed, ocean run, seine caught fish and are even more efficient when operated on female only fish, so, combinations of the two machines mentioned above improve efficiency of the grading and processing operations. Where possible, it is best to keep the fish in the same boxes or containers without re-icing as the less the fish is handled, the longer the quality will be maintained. It may be necessary, however, during the off-loading procedure to re-ice the fish. With some species, the fish may be off-loaded, separated from ice, washed and re-iced prior to placing in chilled storage to wait further processing. The raw material specification is broken down into a number of attributes. Firstly, the species will need identifying; secondly, the size will be stated. Fish which have been mechanically graded should fall within a specified weight range. However, where fish are of mixed sizes a better indication will be given by ‘percent usable fish’ which is the percentage by weight of fish in the required weight range. A minimum acceptable percentage should be stated for this specification. The general condition of the fish may be specified in different ways depending upon whether the fish is fresh or frozen. An example of this for Sprattus sprattus will be as follows: Fresh fish Shining, iridescent with bright colour; Slightly protruding eyes; Little or no blood staining at the gills; Fresh odour; Fresh sea weedy or slightly oily odour; Containing no feed; Free from disease and with no obvious infestation with parasites; Minimum of damage; and No burst bellies. Frozen fish General appearance good; Fairly firm flesh; Eyes flat or only slightly sunken; Odour slightly oily or neutral and with no off odours particularly at the gills; Containing no feed; No burst bellies; Very little skinning or damage; No evidence of disease or parasitic infestation; and Blocks well glazed to minimise the development of rancidity.

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For some species, the fat content of the fish will normally be specified. In the case of fresh fish of known origin, samples may be taken on a daily basis. This will enable the quality team to check the variation of the fat content throughout the season. Consequently it is then possible to correlate variations in texture or eating qualities in the final product with the variations in the fat content of the fish. In the case of frozen raw material the fat content must be checked to ensure that it falls within the acceptable range laid down in the product raw material specifications prior to the fish being defrosted in the cannery. The fat content of fresh fish should be monitored throughout the year, to provide evidence of seasonal variations (day-to-day variations should be insignificant). An example of this is Atlantic mackerel which may have oil content as high as 34% at the beginning of the season and fall to 13% by the end of the season. The very high oil content causes problems in handling and during cooking, giving a very soft product. Also, when used in cans which have sauces added the high percentage cook-out of oil dramatically affects the sauce texture and appearance after processing in the can. Frozen blocks should be checked for weight of fish after thawing as this will affect the yield and consequent overall profitability of the operation. In the case of fresh fish, weight checks should be made on a random basis on receipt at the factory. Automated and semi-automated systems within the processing area can give accurate assessment of yield throughout the day using microprocessors linked to weighing equipment and a computer system.

5.7 STORAGE Where fresh fish is being used by the cannery, the delay between catching and landing should be as short as possible, ideally less than 12 hours. Where this period is likely to be exceeded there must be some form of refrigeration to hold product at 0◦ C, such as boxing and icing, or use of RSW or fresh water ice slurry to minimise quality deterioration. Once the fish has been accepted in the factory, the maintenance of a fish temperature of 0◦ C is essential if accelerated spoilage is to be avoided. Ideally, storage should be in clean plastic boxes where the fish is mixed with ice and the boxes are held in an insulated chilled room operating at between 1 and 2◦ C. This allows the ice to melt thereby cooling the fish with cold melt water and the relatively low temperature of the surrounding air ensures that the ice is not wasted by absorbing heat from the air. The result is a reduced usage of ice and the quality of fish is maintained. An alternative method of storing fresh fish is to use refrigerated freshwater; the water may be cooled to 0–2◦ C by adding ice or by using a mechanical refrigeration method. There are some advantages to be had in using this method; the bulk of fish in water can be handled mechanically in the factory and where the fish have already been stored in refrigerated sea water on board the fishing vessel, this may be an advantage when using pumping for off-loading ship-to-shore. The fish are less likely to be bruised using such techniques and where cooling is required, the cooling will be fairly uniform throughout the total mass of fish. Where fish is pumped ashore from refrigerated holds on the fishing vessel, the fish may be discharged into large vats or tanks which are kept cool using ice to maintain the low temperature (see Figure 5.4). Such systems are automated and the fish is removed from the vat as required using hydraulic conveying systems or slatted conveyors (see Figure 5.5). Where frozen fish is to be stored, the temperature of the cold store should ideally be at −30◦ C. At this temperature fatty fish may be kept for up to six months with little deterioration in quality. The main problem in extending cold storage of fatty fish is rancidity. The degree of rancidity is

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Fig. 5.4

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Hydraulic pumping of fish, ship to shore. (Photo courtesy of Tony Garthwaite.)

Fig. 5.5 Storage tank in factory showing in-feed system in the foreground and hydraulic discharge system at the back of the tank. (Photo courtesy of Tony Garthwaite.)

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accentuated by higher temperatures, inadequate glazing of the block and extended period of storage. Lipid oxidation proceeds rapidly at temperatures as low as −18◦ C. Below this temperature, the rate of oxidation decreases quickly. Fat oxidation rate is reduced by a factor of 2 or 3 for every 10◦ C reduction in temperature. As storage time progresses, denaturation of protein will cause toughening of the flesh of the fish. In order to maintain quality, it is essential that good practices be followed in chilled store and cold store management. Strict rotation of stock must be observed. For traceability purposes, all pallets should bear a sequentially numbered ticket which states the product, its production date and the source of raw material. As mentioned earlier, this may take the form of a barcode sticker. Other items which may appear on the ticket could be quality grade, count per kilogram, date into store, etc. Generally, plastic or metal pallets are in use in the food industry. However, where wooden pallets are used, frozen blocks should not be placed directly on to them but a suitable plastic liner placed between the block and the wooden pallet. Ideally, blocks should be individually glazed and bagged; this will help reduce the rate of oxidation of the fish oil.

5.8 DEFROSTING FROZEN FISH 5.8.1

General

Large quantities of fish are frozen as a means of preservation and storage prior to use in the canning process. The defrosting of this fish is of considerable interest to the processor. Careful thawing is essential if product quality is to be retained. Generally, rapid thawing is more advantageous as it limits the exposure of the product to high temperatures, which cause deterioration in quality. When frozen fish is thawed in air or water, the surface ice melts to form a layer of water. Because water has a lower thermal conductivity as well as a lower thermal diffusivity than ice, the rate at which heat is conducted to the frozen part of the fish is reduced as the thickness of the water layer increases. Effectively, as the fish defrosts so the thawed outer surface acts as an insulator to heat transfer. During the freezing process, as the layer of ice builds up, so the heat transfer rate increases, consequently it takes longer to defrost material by simple heat transfer than it does to freeze the same material over the same temperature range, using similar parameters. There are two main groups of thawing methods used today. The first group includes those methods whereby heat is conducted into the fish from the surface whilst the second group is concerned with methods where heat is generated uniformly throughout the fish. Whichever method is used the system should avoid:

r r r r

Localised over heating of the fish; Excessive drip loss; Dehydration; and Bacterial growth.

There are a number of systems used for application of heat to the surface of the fish. These include exposure to still or moving warm air, spraying with water, immersion in water or condensation of water vapour on the surface. In all these methods the outside of the fish thaws first and, as mentioned earlier, reduces the ability to conduct heat, thus increasing the thawing time. These methods are also limited by the need to avoid overheating of the fish. In the United Kingdom it is recommended that the temperatures should not exceed 20◦ C (seafish; Jason, 1981) but in tropical countries this is often

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Fig. 5.6

117

Thawing chamber. (Reproduced with permission from Cabinplant A/S.)

impossible to achieve without the use of chilled storage facilities. The use of higher temperatures for the heating medium increases the rate of heat transfer, but may result in localised overheating, which could lead to the cooking of the fish, and a consequent break-up of the flesh.

5.8.2

Air thawing

Thawing in still air may be considered the simplest of the thawing methods for frozen blocks of whole fish and whilst for small quantities it is an inexpensive method, it is not without its drawbacks. The temperature of the air should be between 15 and 20◦ C. Lower temperatures result in extremely slow thawing rates resulting in softening of the flesh and reduced yield in further processing. Higher temperatures also result in product deterioration and at temperatures greater than 30◦ C some fish from colder waters may cook resulting in break-up of the flesh. Thawing in still air is feasible for small quantities. It has the disadvantages of requiring a considerable amount of space, handling and the time taken to defrost is often very long (normally 10–24 hours depending on the size of the fish block). It does however have the advantage that little equipment is required.

5.8.3

Air blast thawing

Frozen fish can be thawed much more rapidly under controlled conditions using air blast thawing, typically saving 70% of the thawing time, (Figure 5.6). Thawing in still air requires long periods of time because the rate of heat transfer between air and fish is very low. This rate of heat transfer may be increased by using high-velocity air passing across the frozen fish. Velocities of 8–10 m/s are used in industrial units, above this speed little increase in heat transfer rate is achieved (Burgess et al., 1967). Thawing using moving air may be continuous or batch operated. Continuous thawing systems utilise a conveyor belt on which the frozen blocks of fish are placed and carried through a blast thawer where air at temperatures maintained between 15 and 20◦ C is blown across the conveyor belt. In batch thawers, frozen blocks are loaded on to special racks or trolleys. The trays are designed for maximum airflow, resulting in a minimum processing time. The air flowing through the chamber is driven by reversible fans which result in more uniform thawing of the material. Because of the moving air over the surface of the product, the avoidance of dehydration is essential to achieve high yields with no deterioration in the quality of the product. This is achieved

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Fig. 5.7 Commercial thawing chamber showing trollies with frozen blocks. (Reproduced with permission from Cabinplant A/S.)

by using air which is as nearly saturated as possible. Heat exchangers and banks of water sprays in the plenum chambers of air blast thawers are used to achieve the desired objective. Frequent cleaning of air blast thawers is vital for both hygienic and operational considerations. One problem encountered with air blast thawing is the larger fish remaining partially frozen at the centre whilst being warm at the surface. In such cases, storing the fish in a chill store prior to further processing will allow the temperature to equilibrate. Figure 5.7 shows a commercial thawing chamber. Frozen blocks on trolleys are wheeled into the chamber. The doors are closed and a thawing program is selected. Fans now send a tempered airflow into the chamber through guide plates. The air flow circulates between all trolley shelves, thus ensuring even and uniform product thawing. The airflow is reversed at adjustable intervals, i.e. alternately being introduced from the left and right chamber sides, respectively. To prevent product dehydration, the air is kept saturated through constant injection of water particles straight into the airflow. A thin film is formed on the product surface to protect the product and maintain quality.

5.8.4

Water thawing

Where an ample supply of clean water is available, thawing in warm water may be a cheap and simple method of thawing frozen fish. The fish may be immersed in the water or the water sprayed over the fish or even a combination of the two. Whilst thawing in water is simple and inexpensive, it may cause the fish to lose quality in terms of flavour and appearance, and if water is absorbed during the thawing process this may cause problems in subsequent operations during the canning process. Thawing of frozen blocks using water is more rapid than air thawing due to higher rates of heat transfer between the product and water. As with air blast thawing, the velocity of water passing

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Fig. 5.8

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Typical immersion thawer with belt conveyor. (Reproduced with permission from Cabinplant A/S.)

over the product greatly influences the rate of thawing and velocities of 0.5–2 cm/s are used commercially. Where the higher velocity of water is used at temperatures of 18◦ C, blocks 100 mm thick may be defrosted in periods of 4–5 hours (Archer et al., 2008). Typical immersion thawers consist of a tank in which vertical baffles are placed causing the water to flow backwards and forwards across the tank as it moves from the inlet end to the outlet at the opposite end. The fish blocks are placed between the baffles and the flow of water should be such that the fish blocks at the downstream end of the tank do not thaw too slowly. In practice it is normal for a usage rate of four tonnes of water per tonne of fish to be thawed. Continuous thawers may use sprays and immersion as shown in Figure 5.8 Alternatively, blocks of the frozen fish may be conveyed through a tank of moving water which defrosts the block and thus gives a continuous feed to a production line. Such thawers may have problems due to scales and pieces of fish becoming trapped in the circulation systems of the thawer. Filtration systems and thorough cleaning on a daily basis are essential for this type of equipment.

5.8.5 Vacuum thawing Vacuum thawers consist of airtight chambers into which the fish is loaded using trolleys. A vacuum is drawn in the chamber and water in a tray over the base of the chamber is heated filling the chamber with water vapour. The temperature of the water vapour is typically between 18 and 20◦ C and the vapour condenses on the cold surface of the fish where the latent heat of vapourisation is absorbed by the fish. Heat transfer to the product is much more rapid than the previous method of thawing. Equivalent thawing times may be reduced from 20 hours in air to less than 1 hour in a vacuum thawing unit and the water usage of such units is low. However, care must be taken to ensure that gases released from the fish as thawing proceeds do not cause rupturing of flesh (e.g. belly-burst in herring and mackerel). The advantages of this method of defrosting are that with the exception of a vacuum pump there are no moving parts. Hence the possibility of mechanical breakdown is reduced compared to the previous method. Also, as the vapour is distilled from the water in the tank it condenses onto the fish in a pure state, so there is no risk of contamination from bacteria, which may accumulate within the system. Cleaning for this method is by means of a cleaning in place system (CIP) within the chamber.

5.8.6

Integrated thawing and cooking systems

Modern equipment utilises an integrated thawing, cooking and evaporative cooling system. The frozen tuna are transported into a number of chambers, and the process of thawing, cooking and cooling takes place in one operation.

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The advantages of thawing, cooking and cooling in one machine are:

r r r r r r

High capacity with maximum yield; Reduced water consumption; Reduced waste water; Less manpower; Easy cleaning – CIP; and Data collection of process parameters.

Such an operation requires the size grading of the fish in order to utilise pre-set programmes for the equipment. The consequent reductions in time and water consumption are important economic factors which must be considered when investing in this type of equipment.

5.8.7

Other methods of thawing

Water bath thawing in 18◦ C circulated water and simultaneously exposed to 1500 Hz acoustic energy has been claimed to reduce the thawing time in water alone by 70%. Quality analyses indicated that the flesh was not adversely affected by the acoustic waves (Kissam et al., 1982). Di-electric heating consists of placing the fish between two parallel metal plates across which a high-frequency alternating voltage is applied. The electrical frequency causes dipoles in the water to oscillate as the electrical field direction changes. The frictional energy produced heats the fish resulting in defrosting of the block. Rapid thawing of the product is possible but localised overheating may cause problems. This can be avoided by applying the di-electric effect for short periods interspersed with a tempering period in order to dissipate the heat produced. Defrosting using microwave heating is also possible. Again, localised heating is a problem with this method. Though the use of electrical methods of thawing results in a much more rapid defrosting of products, it is very costly in terms of capital expenditure. However, if correctly applied it can result in good-quality fish with reduced drip loss from the product. There are recommended product, air and water temperatures for thawing fish as follows: Maximum air or water temperature (◦ C)

Maximum product temperature (◦ C)

Codex standard for air thawing frozen fish blocks

25

7

Codex standard for water thawing frozen fish blocks

25 ± 1.5

7

International Institute of Refrigeration

Air: 25 Water: 25

4–5

Torry Research Station

Air blast: 20 Still air: 15 Water: 18

0–4

The choice of thawing method will depend on a number of factors including the throughput required and whether batch or continuous operations are to be considered. The capital cost of the equipment, the floor area required for its installation and subsequent labour requirements, the maintenance and other running costs as well as availability of steam and hot water will also influence the decision.

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Fig. 5.9 Showing Mackerel nobbing by hand, with head removed and guts being extracted from the body cavity. (Photo courtesy of Tony Garthwaite.)

5.9 FISH PREPARATION During the production operation visual inspection is of paramount importance for determining the quality of the raw material entering the can. Where there is a delay prior to further processing in the cannery, this enables further quality checks to be made prior to the packing operation.

5.9.1

Heading

Heading involves removing the head of the fish from the body and is achieved by two different methods. The simplest method is by means of a straight cut perpendicular to the backbone of the fish made just behind the head. This method is simple and fast but results in a reduced yield. The second method is termed a ‘V-cut’ where the cut is made from behind the gills but slanting diagonally forward to the point of the backbone. This achieves an increase in yield from meat which is located near the backbone carried at the dorsal side of the fish. Such a cut may be used where heading is carried out by hand or where the value of the fish flesh saved is sufficient to pay for the increased cost of machinery or labour required to carry out such an operation. Where machines are used, the heads may be removed using a circular saw for both types of cut whereas the straight cut may utilise a bandsaw or guillotine. Heading machines are normally adjusted to accept fish of a certain length and shape. Using a straight cut machine, fish are normally headed by loading onto a slatted conveyor belt, the nose of each fish being pressed against an end plate. The conveyor then moves the fish towards the saw blade or the guillotine, which removes the head. This in turn is guided down a chute to a waste collection point, whilst the body of the fish moves on to the next part of the process. Some straight-head cutting machines are modified to remove the head and pull out the viscera at the same time. Such an operation is known as ‘nobbing’ (Figure 5.9). To achieve the V-cut, a machine with two rotating circulating blades is used and the position of the blades is adjusted to yield as much meat as possible whilst still removing the collarbone and pectoral fins with the head.

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Fig. 5.10 Conveyor feeding sardines to the top of the orientation system seen in Fig. 5.11. (Photo courtesy of Tony Garthwaite.)

For smaller fish, such as sardine and sild and even mackerel, machinery is a viable alternative (Figures 5.10 and 5.11) where the cost of manual labour is high. However, for larger fish the manual removal of the head will result in greater economies of yield. Where shrimps and prawns are used for canning, they must also undergo a de-heading operation. In many parts of the tropics especially in the countries of South-East Asia, this operation is carried out by hand. The operation is achieved by squeezing the shrimp just in front of the tail section between thumb and fingers, then, with a slight twist, removing the head from the tail. Mechanical removal of the head is achieved by using either a guillotine or a rotating knife which cuts off the head after the shrimp is correctly positioned on a slatted conveyor belt similar to that described for the de-heading of fish. This operation is often carried out at the same time as peeling of shrimps and prawns.

5.9.2

Filleting

The process of removing the complete musculature from each side of the fish is known as filleting. This may be achieved manually or by using machines. For the canning industry, because of the large quantities of fish processed daily, it is usual for the smaller species to be filleted using machine.

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Fig. 5.11

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Orientation system. (Photo courtesy of Tony Garthwaite.)

Filleting machines are available commercially for many species of fish but the canning industry is mainly concerned with herring, mackerel and pilchards. See Figures 5.10–5.12. With mechanised filleting the species such as herring, pilchards and small mackerel may all be filleted using the same machine. This is because they have similar bone structures. The fish are conveyed into the machine orientated relative to the filleting blades. Automatic orientation of the fish is now the norm although some machines still utilise manual orientation. Headed and gutted fish are conveyed into the machine held in a guide which presents the fish to the circular filleting blades. The blades are at fixed angles and the distance from the guides is determined by the thickness of the fish and the distance from the body cavity to the exterior surface of the fish. The angles of the blades relative to the guide will be determined by the skeletal structure and the contours of the external surface of the fish species. Adjustments to the position of the blades are made in order that as much meat as possible is removed with the fillet thus increasing the yield using the machine. Such machines are designed to accept an optimum length fish. Where fish that are larger or smaller than this optimum size are filleted on the machine, the yield will be reduced. These machines, whilst not removing as much flesh as a skilled filleter, do process greater quantities of fish in a given time. The capacity of such machines may be up to 300 fish a minute where machines are fed by up to four operators. This greatly reduces the labour cost of the filleting operation. Against this increased efficiency, water consumption must be considered, which may be up to 40 L/min. The water must be of potable quality and an adequate supply is essential for the operation of such automatic machines.

5.9.3

Skinning

The decision to remove the skin or not will depend upon the product to be produced. Some fish have hard scales which need to be removed before the fish is further processed and placed in the can. Herring is such a fish and the scales are removed from the skin by rubbing against a rough surface in such a manner so as to remove the scales. Generally, automatic scalers consist of a horizontal cylinder fabricated from horizontal metal bars or having a rough internal surface. Fish are fed into

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Fig. 5.12

Feeding the fish head first to the nobbing system. (Photo courtesy of Tony Garthwaite.)

one end of the cylinder, where the slope of the axis and the rotational speed will determine how long the fish are in the scaler before being discharged at the other end. The fish tumble inside the rotating cylinder and as the fish move across the rough internal surface the scales are removed. As with filleting machines large quantities of water are required in this case in order to wash the fish to assist in the removal of the scales and carry them away. For fish with soft skins, such as mackerel, caustic peeling is preferable. This entails feeding the fish on a continuous basis through a tank containing caustic soda solution at a pH of between 11 and 13. The recommended strength is to achieve a pH of 11. However, when operating to this pH excessive subsequent trimming of fins and skin is sometimes required and pH values of up to 13 are used in order to avoid extra labour later in the process. On leaving the caustic tank the fish are immersed in a neutralising tank using hydrochloric acid operating at pH 3. The fish are subsequently washed using water jet sprays and loose skin is removed during the washing process. At the end of the process the fish should be at a pH 7. The total time period from entering the caustic bath to leaving the acid bath will be in the region of 20 minutes.

5.9.4

Smoking

Traditionally, the objective of smoking fish was to increase the shelf-life of the raw material. With modern smoking, procedures are designed to impart the desired sensory characteristics to the fish

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Fig. 5.13

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Sardines entering a continuous brining machine. (Photo courtesy of Tony Garthwaite.)

uniformly and with consistency from one batch to another. Where the fish are to be smoked prior to canning, the extension of shelf-life of the product is not in consideration as the subsequent sterilisation process will achieve a much longer shelf-life than is possible with the smoking process alone. The smoking of fish may be divided into two types, cold smoking at temperatures below 30◦ C and hot smoking where temperatures greater than 80◦ C are achieved. Cold smoked fish are usually non-fatty fish such as haddock and cod. Here, the process imparts a smoke flavour, which satisfies the demands of the consumer. The hot smoking process is used mainly for fatty fish such as herring and mackerel and with shellfish it is generally limited to oysters and mussels (Horner, 1992). Poly aromatic hydrocarbons (PAH) are some of the hundreds of constituents of wood smoke. They are of particular interest because they are carcinogenic, the most important one being 3,4benzpyrene. Concentrations of PAH are influenced by the method of smoke generation, temperature of combustion, the available air supply, type of wood, length of time of smoking and smoke temperature. High-temperature smoking is best to limit the PAH concentration in the smoke and ultimately in the product (Magger, 1987). All smoked fish are salted prior to the smoking process. The prepared fillet or shellfish meat is submerged in a brine solution long enough to absorbed salt to a desired concentration. The concentration achieved can be varied depending upon the product and the customer’s requirements. Generally, fully automatic brining machines are employed by the industry (Figure 5.13). The machine consists of a tank containing brine solution together with a mechanised conveyor belt and a paddle system normally with variable speed control. This is used to pass the fish through the brine tank at a preset rate, thus ensuring that the fish are immersed in the brine for the ideal length of time. This will ensure a consistent quality of product and a constant salt content in the finished product. The fish enters the system via an elevated conveyor hopper which is fed from the filleting machines or is hand loaded at a rate determined by the requirements of the processing line subsequent to the briner. The salted fish leaving the brining tank will be placed on trays, which when fully loaded are positioned on to smoking trolleys for transportation into the smoking kilns.

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Reversible circulating fan

Smoke inlet ducting

Heat exchanger

Smoke stabilizer

Control panel

Discharge fan

Exhaust to atmosphere smoke discharge flue Fresh air intake Automatic humidity control

Automatic smoke generator

Inlet/ outlet plenum Auto-clean system

Diffuser wall

Trolley guide rails

Booster heat exchanger

Product trolleys

Diffuser wall

Fig. 5.14 Schematic diagram of a mechanical smoking kiln, showing how smoke is directed around the kiln to give a uniform flavour to the product. (Reproduced with permission from AFOS Ltd.)

The concentration of brine solution used may vary between 50 and 100% saturation. High concentrations of salt will permit shorter dwell times in the brine in order to achieve the desired salt concentration in the end product. As an indication, for mackerel fillets passed through a continuous brining system using brine which is over 90% saturation, the residence time will be between 1 and 2 minutes in order to achieve the final salt concentration of around 3%. The final figure will depend upon three factors. Firstly, the brine concentration; secondly, the length of time the fillet is left in the brine and thirdly, the percentage oil content of the fish. The greater the oil content of the fish, the slower the salt up-take. In the case of shellfish, such as mussels, these are immersed in brine for 4–5 minutes using a brine concentration of 50%. The meats are then drained and dipped in vegetable oil before being laid on mesh trays to drain. Oysters are prepared in a similar manner and in both cases the shellfish may be placed immediately in the kiln. Where fish, whole or in fillet form, have been brined prior to smoking, they are laid on mesh trays constructed from stainless-steel or plastic coated steel and left to drain for a period of 0.5–1 hour. Smoking kilns or if two main types: traditional, where the fish is placed directly over the source of smoke, typically a chimney structure; or a modern mechanical kiln consisting of a main cabinet with air circulating fan, exhaust fan, heat exchangers and controls and a separate smoke generating chamber connected to the main cabinet (Figure 5.14). Smoke generated from sawdust is used in preference to smoke from burning wood, this produces a cooler fire and more smoke as the sawdust smoulders rather than burns and gives smoke with more flavouring properties. Smoke may be produced by means of friction against a block of timber or sawdust may be dropped onto a hot plate which is electrically heated and causes the sawdust to smoulder. Modern smoke generators feed sawdust slowly onto a hot surface producing full smoke output in a matter of minutes, and requiring little attention other than to keep the hopper filled with sawdust. A sawdust feed hopper is fitted with variable speed output drive which provides controlled quantities of sawdust to an electrically heated combustion plate. The volume of combustion air is also varied

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providing maximum control of smoke density with economy of sawdust usage. The smoking cabinet is a self-contained unit which includes an air-circulating fan, a exhaust fan, heat exchangers and humidifiers. Depending upon the design, the smoke/airflow may be vertical or horizontal. Some kilns allow for reversal of the direction of airflow, thus ensuring greater uniformity of smoke uptake by the product on the trolleys. Modern mechanical kilns incorporating the latest production technology and microprocessor controls allow programming which will ensure a consistent smoked product and also guarantee yields at the end of the process. This is a distinct advantage to the smoked fish canner where a reduction in the amount of drying which takes place during the smoking process may give both higher yields and better quality finished products in the can. Operation of the smoking kiln is such that air is circulated around the smokehouse and conditioned to the correct temperature (using thermostats) and humidity (using water sprays) in the heat exchangers located in a plenum. The humidity is monitored by humidity detectors positioned in the air stream. Smoke is drawn into the kiln from the smoke generator through a connecting duct and mixed with re-circulating air and fresh air before passing through the heat exchanger to ensure the correct temperature is maintained. Fans circulate the mixture of smoke and air at a controlled velocity aimed at a maximum deposition of smoke flavour in the fish. The smoke generator is normally positioned outside the production area and the smoke is drawn into the kiln via an extended duct leading from the generator to the kiln. The choice of wood used for smoking depends upon the types of wood available and the desired flavour in the final product. Almost any hard wood may be used but resinous soft wood should not be used as it results in high PAH levels in the smoked fish. Because of this, hard wood chips or sawdust are generally preferred. Where available, oak is normally the preferred type of wood for hot smoking of fish. However, other woods such as hickory, cedar and eucalyptus may also be used to produce smoke and in some parts of the world coconut husks, spent sugar-cane or rice husks may be used. It is important that sawdust and wood chips are sourced from timber which has not been treated with preservatives or painted prior to use.

5.9.5

Pre-cooking

The eventual thermal process designed to sterilise the fish in can is more than adequate to cook the fish in order to make it palatable. Pre-cooking of fish prior to filling is carried out to assist in the packing operation or when this occurs in the container it is designed to remove excessive aqueous cook-out liquor from the fish flesh. Such a liquid often causes a detrimental appearance in the finished product (Figure 5.15). One use of pre-cooking is in the production of boneless mackerel fillets where the fish is conveyed to a cooking bath operating at around 90◦ C immediately after a caustic skinning operation. The cooking takes approximately 25 minutes, at the end of which a short spray cooling stage precedes the packing into cans. In the cooked form it is easy to separate the two fillets from either side of the fish skeleton (Figure 5.16). These may then be placed directly into cans or placed onto modified conveyors leading to automatic can filling machinery. Large tuna may be up to 20 kg in weight and must be pre-cooked prior to preparation for insertion in the can. Cooking in steam at atmospheric pressure may take up to 4 hours to complete and should target for achieving a backbone temperature of 70◦ C. They are then allowed to cool in chill-rooms for 24 hours, allowing the flesh texture to become firm and easier to handle in the trimming operation, during which the head, skin, spine and dark flesh, which underlies the lateral line, are all removed. The flesh which remains is then packed into cans as solid steaks to produce a premium product whilst the off-cuts are packed as chunks or flakes.

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Fig. 5.15 (a) Close-up view of trolley with packs of frozen prawns for defrosting. (b) Integrated thawing cooking and cooling unit. (Reproduced with permission from Cabinplant A/S.)

Fish quality

Fig. 5.16 waite.)

129

Removing backbone from skinned mackerel to produce mackerel loins. (Photo courtesy of Tony Garth-

In the case of shellfish, molluscs are pre-cooked in order to remove the meat from the shell, and this operation is known as a shucking and is normally achieved by the use of pressurised steam at 3 Bar pressure (absolute) for a period of 30 seconds, followed by rapid reduction to 2 Bar. Immediate quenching with cold water is required to reduce the evaporation which causes textural damage due to dehydration. In the case of crustaceans, such as crabs, pre-cooking is required in order to facilitate the extraction of the white meat from the claws and carapace prior to filling in the can. Shrimps and prawns are pre-cooked after removal of the head and shell from the tail, by immersion in a tank of hot brine. The time of cooking is up to 4 minutes and the meat becomes white and firm and containing the characteristic curl which assists in subsequent size grading prior to filling in the cans.

5.9.6

Storing prepared fish

In most fish-canning operations once a fish has been prepared for canning the processes is continuous. However, this may be disrupted by machinery breakdown or as in the case of smoking; the preparatory process may take place in a separate part of a factory or indeed on a separate site. This normally requires storage of the prepared material for short periods of time and a maximum period of 20 minutes is a useful guideline, though this will depend upon the ambient temperature (higher temperatures allow less time delay). Prepared fish and shellfish, if left standing for even short periods of time, will tend to deteriorate faster than the raw material in store (2–3◦ C) due to the temperature of the fish being slightly higher as it will have absorbed heat from the atmosphere in the processing area, or, as in the case of smoking from the preparatory process itself. As in the case of raw material the rate of spoilage may be reduced by bringing the temperature down to chilled temperatures of 0–2◦ C. Smoked fish to be used for canning should be chilled as quickly as possible after the smoking process unless it is to be used immediately in the packing operation. Ideally, such fish should be stored in a separate chill room due to the problems of cross-contamination of smoke flavour to no smoked raw material. Where the use of a separate chill store is impossible the problem may be reduced by storing the fish in plastic trays with lids. However, this will not guarantee the avoidance of tainting of other fish stored in the same room. Where prepared fish must be stored at the end of a day’s production or because of a breakdown on the packing line, the fish should be moved to

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the chill room as quickly as possible and stored in clean plastic boxes. Depending on the state of preparation, the fish should be iced top and bottom or be covered with a thin polythene sheet in order to reduce dehydration on the surface. In some situations the use of ice may act as a leaching agent. This may be reduced by placing the ice in polythene bags and resting the bag on top of the fish thus achieving both cooling and reduction of evaporation in one operation; however, it must be noted that for long-term storage such trays should be placed in a chill room. Care must be taken not to store too great a depth of prepared fish as fish in the lower layers will lose fluid due to the pressure of the fish above. As with the storage of raw material prior to processing, the containers of prepared fish should be labelled clearly for identification and stock rotation purposes.

5.10 CHEMICAL INDICATORS OF QUALITY Quality of fish and shellfish may be checked using chemical analysis in three separate groupings, outlined below. Firstly, the analysis of TVBN (total volatile basic nitrogen) and TMA-N (tri-methylamine nitrogen). These tests are carried out in order to obtain guidance regarding the freshness of the sample and may form a useful back-up to sensory analysis. Secondly, the analysis for histamine. Canned fish have been implicated in several outbreaks of histamine poisoning, also known as Scombrotoxin poisoning because of its frequent association with scombroid fish such as tuna and mackerel. In the UK, a survey showed that canned seafood accounted for 42% of the histamine poisoning outbreaks during the period 1976–1982. The histamine accumulates in the fish before thermal processing, especially during long periods of un-refrigerated storage or transport (Hardy and Smith, 1976). Histamine, being fairly thermal stable, is not affected by the heat of the retorting process and is therefore found in the finished canned product even though the bacteria responsible for its presence have been destroyed. The EC 1991 fish hygiene directives (Annex chapter IV, paragraph 3) lays down limits for histamine content of not more than 200 ppm in any sample with not more than two samples containing between 100 and 200 ppm and a mean value of less than 100 ppm, for nine samples taken from one batch of fish. The same regulations cover the third group which is the analysis for heavy metals, in particular mercury, lead and tin. In the case of lead, the advent of the welded seam has reduced the danger from the can itself, but it should be remembered that the fish chain does have a great ability to assimilate heavy metals from contaminated waters and so produce contaminated products. In conclusion, the internationally demanding legal requirements of the European, North American and Japanese governments require that the handling of the raw material for fishery products is of a particularly high standard. The internationally accepted standards for quality systems such as ISO and BRC are useful tools for ensuring the control of quality throughout the raw material chain as well as the complete process. It is beyond the scope of this book to cover this topic but the reader is urged to give the subject consideration.

REFERENCES Aitken, A., Mackie, I.M., Merritt, J.H. and Windsor, M.L. (1982) Fish Handling and Processing. HMSO, London, UK. Archer, M., Edmonds, M. and George, M. (2008) Seafood Thawing. www.seafish.org/pdf.pl?file=seafish/ Documents/SR598 Thawing.pdf

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Borgstrom, G. (1965) Fish as Food , Vol. 4, Academic Press, New York. Burgess, G.H.O., Cutting, C.L., Lovern, J.A. and Waterman, J.J. (1967) Fish Handling and Processing. HMSO, London, UK. Hardly, R., McGill, A.S. and Gunstone, F.D. (1979) Lipid autoxidation changes in cold stored cod. Journal of the Science of Food and Agriculture, 30(10), 184–195. Hardy, R. and Smith, J.G.M. (1976) The storage of mackerel. Development of histamine and rancidity. Journal of the Science of Food and Agriculture, 27, 595–599. Horner, W.F.A. (1992) Fish Pocessing Technology, edited by Hall, G.M., Blackie, Glasgow, UK. Huss, H.H., Jacobsen, M. and Liston, J. (eds) (1992) Quality Assurance in the Fish Industry. Developments in Food Science, Vol. 30, Elsevier, Amsterdam, the Netherlands. Jason, A.C. (1981) The storage of herring in ice, R.S.W. and at ambient temperature. Advances in Fish Science and Technology, 108–175. Kissam, A.D., Nelson, R.W., NGAO, J. and Hunter, P. (1982) Water-thawing of fish using low frequency acoustics. Journal of Food Science, 47(1), 71–75. Konagaya, S. (1983) A review of the abnormal conditions of fish meat: jellied meat and yake-niku, spontaneously done meat. Journal of the Japanese Society for Food Science and Technology, 29(6), 379–388. Labuza, T.P. (1970) Properties of water as related to the keeping qualities of foods. Proceedings of the Second International Congress. Food Science and Technology. Institute of Food Technology, pp. 618–635. Labuza, T.P., Tannenbaum, S.R. and Karel, M. (1970) Water content and stability of low moisture and intermediate moisture foods. Food Technology, 24, 543–550. L´opez-Sabater, E.I., Rodr´ıguez-Jerez, J.J., Hern´andez-Herrero, M. and Mora-Ventura, M.T. (1994) Bacteriological quality of tuna fish (Thunnus thynnus) destined for canning: effect of tuna handling on presence of histidine decarboxylase bacteria and histamine level. Journal of Food Protection, 57, 318–323. Magger, J.A. (1987) The flavour chemistry of wood smoke. Food Review International, 3(1 and 2), 139–184. Putro, S. and Wutti-jumnong, P. (1989) Studies on stability of dried salted fish. In Conference Proceedings, Food Preservation by Moisture Control, pp. 261–268. Elsevier Science Publishers, London, UK. Shenoy, A.V. and Pillai, V.K. (1971) Freezing characteristics of tropical fishes. I. Indian oil sardine. Fishery Technology, 8(1), 37–41. Slabjy, B.M. and True, R.H. (1978) Effect of pre-process holding on the quality of canned Maine sardines. Journal of Food Science, 43(4), 1172–1176. Taylor, S.L. (1986) Histamine food poisoning: toxicology and clinical aspects. CRC Critical Reviews in Toxicology, 17(2), 91–128. Taylor, S., Leber, E.R. and Leatherwood, M. (2007) A survey of Histamine levels in commercially processed scombroid fish products. Journal of Food Quality, 1(4), 393–397. Warne, D., Foran, M. and King, M. (1987) Histamine control survey in canned tuna. Infofish Marketing Digest, 2/87. Yamashita, M. and Konagaya, S. (1991a) Participation of cathepsin L into extensive softening of the muscle of chum salmon caught during spawning migration. Bulletin of Japanese Society Fish, 56(8), 1271–1277. Yamashita, M. and Konagaya, S. (1991b) A comparison of cystatin activity in the various tissues of chum Salmon between feeding and spawning migrations. Comparative Biochemistry and Physiology, 100A(3), 749–751.

6

Design and operation of frozen cold stores

Stephen J. James and Christian James

6.1 INTRODUCTION Many of the raw materials used for canning, including notably tuna and sardines, as well as salmon, mackerel, herring, clams, oysters, shrimps, octopus, crab and white fish paste products (Myrseth, 1985) may be supplied frozen and stored in a frozen state prior to final canning. The principal reasons for this are that: 1. Fish and shellfish deteriorate rapidly even at chill temperatures and may be caught far from their intended market. Freezing enables the supply of high-quality raw material to be transported from their place of catch to distant markets for canning (IIR, 2006). 2. The season for many fish and shellfish is relatively short, or quantities vary throughout the year. Consequently freezing and frozen storage can be used to iron out peaks and troughs and thus enable continuity of supply (IIR, 2006). There is a clear difference between the environmental conditions required for freezing fish and fish products, which is a heat removal/temperature reduction processes, and those required for subsequent frozen storage where the aim is to maintain a set product temperature. However, in many air-based systems freezing and frozen storage take place in the same chamber and even where two separate facilities are used, in many cases not all the required heat is removed in the freezing phase. This failure to remove the required heat can be due to a number of causes:

r r r r r

Insufficient time allowed; Insufficient refrigeration capacity to cater for high initial product load; Overloading; Variability in size of products; and Incorrect environmental conditions.

If the mean temperature of the frozen product is at or below the desired storage temperature then the frozen storage room can be designed and operated to eliminate any heat flow in the frozen product and thus maximise the high-quality storage life of the fish. If the system has to cater for the input of a ‘warm’ product then the design can never be optimised and will be a compromise. Extensive data are available on the optimum storage conditions and attainable frozen storage lives for fish and seafood products (ASHRAE, 2006; IIR, 2006). However, it must be pointed out that many of the published data are based on old scientific studies with different packaging systems to those currently used, or expert option.

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6.2 FACTORS AFFECTING FROZEN STORAGE LIFE The factors that influence the storage life and quality of frozen fish may act in any one of three stages: prior to freezing, during the actual freezing process and post freezing in the storage period itself.

6.2.1

Definition of frozen storage life

There is a wide range of rather confusing definitions used to define storage life. The EC directive (Commission of the European Community, 1984) states simply that frozen storage must ‘preserve the intrinsic characteristics’ of the food. Although this is probably every food technologist’s aim, many different criteria can be used to measure these characteristics. The IIR recommendations (2006) define frozen storage life as being ‘the physical and biochemical reactions which take place in frozen food products leading to a gradual, cumulative and irreversible reduction in product quality such that after a period of time the product is no longer suitable for consumption or the intended process’. This definition tends to indicate that a frozen product may deteriorate until it is in a very poor condition before storage life ends, and so rather contradicts the EC definition. IIR (2006) recommendations also include the term of practical storage life (PSL). PSL is defined as ‘the period of frozen storage after freezing during which the product retains its characteristic properties and remains suitable for consumption or the intended process’. Bøgh-Sørensen (1984) describes PSL as ‘the time the product can be stored and still be acceptable to the consumer’. Both of these definitions of PSL depend on the use of sensory panels, leading to the difficulty of defining acceptability and selecting a panel that represents consumers. Another term referred to is ‘high quality life’ (HQL). This concept was developed in the ‘Albany’ experiments started in 1948. HQL is ‘the time elapsed between freezing of an initially high quality product and the moment when, by sensory assessment, a statistically significant difference (P < 0.01) from the initial high quality (immediately after freezing) can be established’ (IIR, 2006). The control is stored at −40◦ C or colder to minimise quality changes. Although well suited to research work, some drawbacks have been noted. The actual definition of storage life and the way it is measured has therefore been widely left to the assessment of individual authors. In some cases sensory assessment has been coupled with chemical or instrumental tests which although probably more repeatable than human judgements are again used at the author’s discretion. Food technologists have no standard way of estimating shelf life. Researchers have used many different methods of assessing samples, often with little thought of the initial quality, pre-freezing treatment or size of their samples. This deficiency has led to poor conclusions and recommendations that can be misleading to users of the data.

6.2.2

Effect of pre-freezing treatment on storage life

The susceptibility of fish and shellfish to spoilage makes rapid cooling a necessity. As soon as a fish dies, spoilage begins (Johnston et al., 1994). The spoilage of fresh fish can be caused by a number of different factors, some of which inter-relate. To maintain a high-quality product, there is a limit to how long fish can be kept chilled before freezing. This time varies between species and seasonally within species. For non-fatty fish, such as cod, it may be up to three days, but for fatty fish, such as herring and mackerel, which are not normally gutted when caught, it may be as short as 24 hours (IIR, 2006). Small fatty fish, such as sardines, should be frozen within only a few hours of catching.

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In general, whole fish have a longer storage life than fillets, which are more stable than mince (Hedges and Nielsen, 2000). Evisceration before freezing can improve storage life since blood contains iron, a co-factor in trimethylamine oxide (TMAO) reactions, and kidneys contain proteolytic enzymes that will degrade the fillet structure (Hedges and Nielsen, 2000). Skin-on fillets also contain more iron that skin-off fillets (Gomezbasauri and Regenstein, 1992).

Rigor changes After death, stiffening of the muscle called rigor mortis sets in and commences due to the action of enzymes. Subsequently, softening of the flesh occurs as these enzymes begin to digest the flesh, affecting the flavour, texture and appearance of the fish. This process can be particularly fast in small fatty fish full of feed, where the gut enzymes are particularly active (Johnston et al., 1994). This may result in the phenomenon known as ‘Burst Belly’, which can occur in only a few hours after catch in sardines, herring and some other fish. Burst Belly is caused by a weakening of the belly wall due to self-digestion from within. Rapid chilling of the fish after catch will significantly slow the rigor processes. The development of Rigor mortis, which occurs over a period of hours or days after death, can have a bearing on handling and processing (Johnston et al., 1994). The muscles under strain tend to contract; therefore, some of the tissue may break, especially if the fish is roughly handled, leaving the flesh broken and falling apart. If the muscles are cut during rigor, they will contract resulting in considerable shrinkage and toughness, thus if filleting is carried out prior to the completion of rigor, it should be carried out pre-rigor and the fillets frozen before rigor commences (IIR, 2006). In many species, however, the contraction during rigor mortis is not strong enough to be of much significance (Johnston et al., 1994).

TMAO changes The enzymatic reactions associated with rigor mortis also result in the formation of substances that may alter the odour and the flavour. Some of these substances, commonly known as extractives, are the first to be changed by the microbiological activity and the protein of the muscles will change considerably later (Johnston et al., 1994). These extractives are present in varying amounts from species to species. Herring and mackerel contain large amounts of amino acid histamine, whereas cod and haddock only contain traces. Skate, dogfish and shark contain large quantities of urea, which is absent in cod (Johnston et al., 1994). TMAO, which is available in all the saltwater fish, is usually absent from fresh water species. The breakdown of TMAO into trimethylamine (TMA) is an important reaction, as the chemical determination of TMA may be used in quality assessment of saltwater fish. Equally important is the determination of the breakdown of urea into ammonia in species, such as sharks, that contain large quantities of urea (Johnston et al., 1994).

Microbial spoilage The growth rates of spoilage microorganisms are highly temperature-dependent and the principal preservative measure, besides good hygienic conditions, is to cool the fish as soon as possible after catching (Johnston et al., 1994). Each type of spoilage microorganism has particular conditions for optimum growth. Thus certain types of microorganism will dominate, depending on the initial infection, the properties of the food material, the temperature and other conditions.

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Protein denaturation and microstructural changes Chemical denaturation of proteins to a noticeable degree appears normally late in the deterioration process, as does oxidation of fat (Johnston et al., 1994).

Lipid hydrolysis and oxidation changes The development of oxidative rancidity is extremely variable in fresh fish (Johnston et al., 1994). There is a great difference between fatty species such as mackerel and herring and fish such as cod and haddock. The former group have a high lipid content, free fat content and proportion of triglycerides, while the latter have a low lipid content, chiefly in the form of phospholipids and lipoprotein immediately associated with muscle proteins (Johnston et al., 1994). Even within a single fish itself there is a difference in the ease with which different portions undergo rancidity. Seasonal variations in susceptibility to rancidity have also been found.

6.2.3

Effect of the freezing process on storage life

Details of the freezing process for fish and fish products can be found in the FAO report ‘Planning and engineering data 3: Fish freezing’ (Graham, 1984), as well as publications such as the IIR ‘Recommendations for the processing and Handling of frozen Foods’ (IIR, 2006) ‘Recommended International Code of Practice for Frozen Fish’ (Codex, 1980) and the ASHRAE Refrigeration Handbook. There are less data to suggest that the method of freezing or the rate of freezing has any substantial influence on the subsequent storage life of fish and shellfish (Lavety, 1991). There is some disagreement in the literature as to whether fast (cryogenic) or slow (blast) freezing is advantageous. Slightly superior chemical and sensory attributes have been found in some studies into cryogenic freezing, but other studies do not show any appreciable advantage, especially during short-term storage. In general overly long freezing times (>6 hours) are not advocated (Heen, 1981; Lavety, 1991). On the other hand extremely short freezing times are likely to cause structural damage if the thickness of the fish or fillet exceeds about 10 mm (Lavety, 1991). Most current freezing processes freeze at rates of around 1 to 2 cm per hour, which is felt to be adequate to reduce undesirable changes during freezing (Heen, 1981).

6.2.4

Effects of intrinsic factors on storage life

Freezing and frozen storage of fish can give a storage life of more than one year, if properly carried out (Johnston et al., 1994). The chemical, biochemical and physical processes that cause chilled fish to spoil will still take place in frozen fish, but at a very slow rate. The one main difference between the spoilage of frozen and chilled fish is that (provided the temperature is low enough, i.e. below −10◦ C) bacterial action will be stopped by the freezing process.

Protein denaturation and microstructural changes Toughening occurs in all white fish due to denaturation reactions in the fish muscle proteins where the proteins develop cross-links with adjacent protein molecules. During frozen storage the endogenous enzyme TMAO dimethylase can catalyse TMAO into dimethylamine and formaldehyde (Aubourg, 2001). Formaldehyde facilitates protein cross-linking, so that protein denaturation and toughening texture are produced (Aubourg, 2001; Sotelo et al., 1995). This damage pathway is especially important in the gadoid family (Aubourg, 2001; Hedges and Nielsen, 2000), where a relatively

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high content of such endogenous enzymes is present. This reduces the water-holding capacity of the fish, and the product becomes dull and spongy, and when cooked cause the flesh to be tough, fibrous and dry (Aubourg, 2001; Hedges and Nielsen, 2000; IIR, 2006; Johnston et al., 1994). The rate at which protein denaturation takes place in frozen fish depends largely on the temperature and will slow down as the temperature is reduced. Some publications stress that even at temperatures of −10◦ C the changes are ‘so rapid that an initially good quality product can be spoilt within a few weeks’ (Johnston et al., 1994). Thus very low storage temperatures, such as −30◦ C (IIR, 2006; Johnston et al., 1994), are advocated to avoid such problems.

Lipid hydrolysis and oxidation changes Endogenous enzymes (lipases, phospholipases, lipoxygenases, peroxidases) are still active during the frozen storage, especially if light or other catalysts (heme groups, transition metals) are present (Aubourg, 2001). The resulting oxidation of lipids during frozen storage leads to objectionable flavours and odours (Johnston et al., 1994), as well as lowering the nutritional value of the product (Aubourg, 2001). Fatty fish are particularly prone to such problems (Johnston et al., 1994), although a slower oxidative change also takes place in low fat white fish such as cod, producing the characteristic ‘cold-store’ odour and flavour (Hedges and Nielsen, 2000; Lavety, 1991). Reducing the storage temperature will slow the rate of these reactions. Glazing or the use of impermeable packaging, especially vacuum packing, can also reduce the exposure of such products to oxygen. Bulk packing of the product will also reduce the degree of oxidation by effectively reducing the ratio of surface area exposed to oxygen. Thus fish frozen in a block surrounded by other fish keep better than fish frozen individually (Johnston et al., 1994).

Myoglobin changes During frozen storage the unaltered myoglobin responsible for the bright white appearance in the muscle of certain fish, which is associated with good quality, slowly oxidises to metmyoglobin, leading to browning development in the muscle, which is less acceptable (Aubourg, 2001). The rate of this change is temperature-dependent and slowed by lower storage temperature (Johnston et al., 1994).

Dehydration During frozen storage, and to a lesser extent during initial freezing, moisture can be lost from the product, leading to dehydration of the fish. At its extreme, severely dehydrated fish will have a dry wrinkled look, and will tend to become pale or white in colour and the flesh will become spongy (Johnston et al., 1994). This is commonly referred to as ‘freezerburn’. As well as the economic consequence of loss of weight and undesirable appearance, drying also accelerates denaturation of the protein and oxidation of the fat in the fish. On unpackaged fish the production of a layer of ice on the surface of a frozen product by spraying, brushing on water, is widely used to protect frozen fish from the effects of dehydration and oxidation during frozen storage. During the glazing process a substantial amount of heat is transferred into the previously frozen fish due to the freezing of the applied water. This heat should be removed prior to frozen storage if the optimal storage life is to be maintained. Dipping into water tanks is not a recommended glazing procedure. Glaze is best applied in an automatic system where the frozen fish is conveyed through sprays mounted above and below the conveying system and the system is designed to rotate the fish during glazing. Glaze on the exposed surfaces of the fish before storage

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will, evaporate over a period of time and drying of the fish itself will resume (Johnston et al., 1994), hence re-glazing during long-term storage is often required. Even totally impervious wrappers used to protect the product do not give full protection if the cold store operating conditions are favourable for desiccation within the pack. In-pack desiccation prevails when there is some free space within the wrapper and the temperature of the store fluctuates. When this occurs, there will be times when the wrapper is colder than the fish and moisture will then leave the product and appear as frost on the inner surface of the wrapper. The total weight of the product and package will not change but if the in-pack dehydration is severe, the fish will have the quality defects associated with excessive drying.

6.2.5

Effects of extrinsic factors on storage life

Three factors during storage, the storage temperature, the degree of fluctuation in the storage temperature and the type of wrapping/packaging in which the fish is stored, are commonly believed to have the main influence on frozen storage life.

Storage temperature To quote from the IIR Red book (IIR, 2006) ‘storage life of nearly all frozen foods is dependent on the temperature of storage . . .’. All of the intrinsic factors (protein denaturation, fat changes and dehydration) affecting the storage life of frozen fish are slowed down by reducing the storage temperature. The FAO Code of Practice for Frozen Fish recommends that frozen fish products should be stored at temperatures appropriate for the species, type of product and intended time of storage. As an example, storage life at a given storage temperature will be related to species, at −18◦ C, for instance, salmon, mackerel, cod can be expected to have a storage life of 4–6, 5–9 and >12 months, respectively (ASHRAE, 1998). FAO advice (Johnston et al., 1994) states that the recommended storage temperature for all fishery products in the UK is −30◦ C and this temperature has also been adopted throughout Europe (Johnston et al., 1994). However, IIR (2006) recommends a storage temperature of −18◦ C for lean fish, such as cod and haddock, and −24◦ C for fatty species, such as herring and mackerel (Table 6.1). They recommend that a temperature as low as −30◦ C is required only for lean fish intended to be kept in cold storage for over a year. A temperature as low as −30◦ C can be considered conservative and is given on the basis that ‘it is not always possible to guarantee that a product will stay in storage no longer than originally intended’ (Johnston et al., 1994) and that ‘cold store operators can seldom be sure to store only one species or type of fish, or to store it for a limited period only’ (Johnston Table 6.1

Practical storage lives (PSL) of fish products (ASHRAE, 2006; IIR, 2006; Johnston et al., 1994). Storage life in months

Storage temperature (◦ C) Fatty fish, glazed Lean fish, fillet Flatfish Lobster, crab, shrimps in shell, cooked Shrimp, peeled, cooked Herring, whole, glazed Blue fin tuna, whole Mackerel, fillet, packaged

−9

−12

−18

−24

−30

3 4

5 9 10 6 5 6 8 3

>9 >12 >18 >12 >9 >9

>12 24 >24

4 2 4 2

12 12

3–5

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et al., 1994). Johnston et al. (1994) state that ‘it has been calculated by an eminent authority on cold store design that under specific conditions, the total cost of operating a cold store at −30◦ C is only 4 percent higher than when operating at −20◦ C although the corresponding percentage increase in running costs will be higher’. For some fish, even lower temperatures, below −50◦ C (so-called ‘superfreezing’), have been advocated (Hedges and Nielsen, 2000).

Temperature fluctuation Generally, fluctuating temperatures in storage are considered to be detrimental to the product. Minor temperature fluctuations in a stored product are generally considered unimportant, especially if they are below −18◦ C and are only of the magnitude of 1–2◦ C. Well-packed products and those that are tightly packed in palletised cartons are also less likely to show quality loss. However, poorly packed samples are severely affected by the temperature swings. There is disagreement on how much effect larger temperature fluctuations have on a product. There is evidence that exposure to temperatures above −18◦ C rather than temperature fluctuations may be the major factor influencing quality deterioration (Gortner et al., 1948; Hedges and Nielsen, 2000). Large swings in temperature can be due to poorly designed automatic defrosting systems in storage rooms which lead to periodic cycles of condensation on and drying of exposed or poorly wrapped fish surfaces.

Packaging To prevent or reduce losses in product quality, it is essential that the frozen product is packaged in such a way as to provide an effective barrier with sufficient impact and compression strength to prevent mechanical damage. The packaging material must have adequate barrier properties to reduce losses due to dehydration and pick-up of taints. A final consideration that is becoming increasingly important is the environmental issue. Considerations should include the impact of the packaging material on the environment, whether or not the package is re-usable or recyclable, whether the package is made from renewable resources and if the package produces pollution when it is being destroyed. The primary package in contact with the frozen product is generally a plastic derived from a natural hydrocarbon source. The choice of which plastic wrapper is dependent on the type of barrier required. Migration of the plasticisers from the wrapping is a potential health hazard and the type of wrapping which can be in contact with food is covered by national legislation. The nonbiodegradability of plastic wrapping material is an environmental issue and toxic compounds, e.g. dioxins can be produced when, e.g. polyvinylidene chloride or polyvinyl chloride (PVC) plastics are incinerated at low temperatures. Secondary packaging is usually a carton that holds a number of primary packages. The secondary package is usually made from boards but can be bands of paper or plastic. Packaging has a large direct effect on storage life, especially in fatty fish and in extreme cases indirectly due to substantially increasing the freezing time. Tertiary packaging is used to hold a number of secondary packages. Tertiary packaging may be palletised for easy handling and wrapped with shrink, stretch wrap or corrugated outers or may be packed in re-usable containers. Wooden pallets are in regular use, but can become a source of contamination. Plastic pallets, which can be colour coded, are more easily cleaned but will support the growth of mould in frozen fish factories. A number of examples have occurred where large pallet loads of warm boxed fish have been frozen in storage rooms. In these cases, freezing times can be so great that bacterial and enzymic activity results in a reduction of storage life. The thickness of packaging will also have an affect on the freezing rate. The rate of heat transfer through packaging material is inversely proportional to its thickness (ASHRAE, 1998); therefore, packaging material

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should be (1) thin enough to produce rapid freezing and an adequate moisture-vapour barrier in frozen storage and (2) thick enough to withstand heavy abuse. In most cases, it is the material and type of packaging that influences frozen storage life. Wrapping in a tightly fitting pack having a low water and oxygen permeability (such as a vacuum pack) can more than double the storage life of a product. Waterproof packing also helps to prevent freezerburn and tight packing helps to prevent an ice build-up in the pack.

Relative humidity and air velocity The rate of evaporation during frozen storage is also related to the relative humidity (RH) of the storage environment. A high relative humidity tends to reduce the evaporation of moisture from the product. The relative humidity of air in a refrigerated room is directly affected by the temperature difference between temperature of the refrigerant in the evaporator cooling coils in the frozen storage room and air temperature in the room. A large temperature difference will result in decreased relative humidity, whereas a small temperature difference between the air and evaporator cooling coils results in high relative humidity. Evaporation from the product will also affect the relative humidity. Thus the relative humidity in a used storage room may be 10–20% higher than that of an empty room (ASHRAE, 1998). The rate of evaporation (M e ) from the surface of a food is given by Dalton’s law: Me = mA(Pf − Pa ) where m is the mass transfer coefficient, A is the effective area and Pf and Pa are the vapour pressure at the surface of the fish and in the surrounding air, respectively. The following is based on an example in the ASHRAE Refrigeration handbook (ASHRAE, 1998): In a frozen cold store operating at −20◦ C, with a 70% RH and a pipe coil temperature of −25◦ C, the moisture-vapour pressure of the air within a package (in direct contact with the frozen fish) would be 109 Pa. The air in the cold storage would have a vapour pressure of 91 Pa, and the moisture-vapour pressure at the coils would be 64 Pa. These differences in moisture-vapour pressure will result in considerable moisture loss from the product unless suitable packaging materials or glazing compounds adequately protects it. In general, because of material costs and space limitations, a temperature difference of 5 K between evaporator coils and room air is the most practical (ASHRAE, 1998). However, there is little scientifically published information on the effect of RH on weight loss during frozen storage, presumably because of the difficulty of measuring RH at temperatures below 0◦ C. However, it should also be noted that the rate of sublimation of ice from a frozen surface is considerably slower than the rate of evaporation from a moist surface, and the ability of air to hold water rapidly diminishes as its temperature falls below 0◦ C. Thus lower storage temperatures will result in lower rates of sublimation. Any increase in air velocity across the surface of the product will also increase the rate of weight loss. Since there is no further requirement to extract heat from the product in frozen storage the air velocity should be the minimum required to maintain a stable uniform temperature around the product. In general air velocities around the product should be <0.5 ms−1 .

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6.3 COLD STORE DESIGN Full details on the design and construction of cold stores for the storage of frozen fish can be found in the FAO publications ‘Freezing and refrigerated storage in fisheries’ (Johnston et al., 1994) and ‘Planning and engineering data 3: Fish freezing’ (Graham, 1984). These publications include details on cold store construction methods and design (including a basic check list for planning a cold store), calculation of cold store refrigeration loads and many operating considerations (including safety instructions). The following sections summarise some of the points raised. The prime purpose of a frozen storage room is to hold a quantity of previously frozen fish or fish products within a set temperature range for a certain time. So in designing a frozen cold store, the initial stage is to obtain some idea of the size of store required. The quantity of frozen fish is normally specified in terms of weight and this has to be translated into a storage volume. However, this is not a trivial operation. To quote from the FAO publication: ‘Figures for density and stowage rate of frozen fish products are not meaningful, unless the exact conditions are clearly defined. For instance, cartons of fish fingers stored on pallets in master cartons can have a stowage rate of between 2.4 and 3.1 m3 /t, depending on the weight in the individual carton packages. Clearly, if this difference exists with such a well-defined and regular shaped item, there will be little benefit to the designer or cold store operator if only average or typical figures are given or, alternatively, figures are quoted as a range to cover all eventualities’. The FAO publication provides tables of data on packing density and stowage rates for a range of fish products including many that would not be of interest to canners, i.e. fish fingers, fish cakes and fish portions in batter. Those that may provide raw material for subsequent canning operations include individually quick frozen (IQF) fillets, fish portions, fillet blocks, whole gutted cod, whole salmon and shelled shrimps. The density of these materials ranges from 0.21 tm−3 (IQF fillets in polystyrene trays) to 1.13 tm−3 (fillet blocks), while stowage rates, including the pallets, range from 7.4 m3 t−1 (IQF fillets in polystyrene trays) to 1.1 m3 t−1 (frozen, whole gutted cod in a compact block). With potentially a sevenfold difference in stowage rates between products, it is very important, when developing a process specification for a store for frozen fish, to have a clear knowledge of the range of products and packaging that the store should accommodate. Usually frozen fish will arrive at the cold store in the form of 1 t pallets with plan dimensions of 1.2 by 1.0 m. If frozen on site it is most likely to be either frozen in the form of 1 t pallets or packed into similar pallets after freezing. In all but the most rudimentary stores some form of mechanical handling system will be used to transfer the pallets from the transport vehicle/freezer to the frozen store and to remove it from the store and move it to the next, probably a thawing or tempering, operation. In a small operation a hand-operated pallet truck may be used for this operation. However, unless the truck is fitted with a high reach mechanism, this will restrict storage in the room to a layer one pallet high or require a manual operation to unpack and repack pallets. Few frozen storage rooms have a height of less than 2 m so stacking two pallets high and more is a common requirement. If the pallets of fish are very regular in shape then it may be possible to stack at least two high without any support structure. In a large frozen cold store stacking six pallets high with a roof clearance height of over 10.5 m is common. In such cases steel racking systems are used with the pallets being loaded using forklift trucks. Traditionally these were petrol or diesel powered, however electric or liquid gas-powered trucks are increasingly common. Modern large cold stores tend to be totally automated using powered racking systems and computer-controlled forklift trucks to load the products into the store and recover them when required. Such procedures minimise the heat ingress into the door through doorways and the heat generated by people or lighting within the store.

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Modern large or medium cold stores are built as one-storey buildings designed for mechanical handling. Low-temperature stores built directly on the ground may require special precautions to prevent the build-up of ice below the cold store floor. The ice formation causes distortion known as ‘frost heave’ and in particularly bad cases, it can lead to the complete destruction of the store and structure of the building. This can be overcome by using insulation in the floors construction and/or heater mats in the concrete. A cold store can be built as an ordinary building using conventional building material, such as bricks, concrete or concrete process sections to which a vapour barrier and insulation is fitted internally. Modern insulation material, in particular polyurethane, has a strength that can be utilised structurally. Consequently, most modern cold stores are constructed using prefabricated panels. The prefabricated laminated panels consist of a layer of insulation bound to outer and inner sheets of facing material that are usually made from a coated metal. The facing material gives the panel strength and also protects the insulation from physical damage. The outer sheet can also provide a suitable heat reflective surface and, most important, it provides a barrier against vapour in the outside air entering the insulation and accumulating as ice. The inner surface is usually finished with a material or coating which is compatible with the storage of frozen food. The choice of insulation is very important as it accounts for a large proportion of the total construction cost. The insulation material and thickness is also important from an energy point of view. Besides a satisfactory thermal conductivity coefficient, the insulation material should also be odour-free, anti-rot, vermin- and fire-resistant and impermeable to water vapour. With some types of insulation, such as polyurethane, a laminated panel allows a thinner layer of insulation to be used. The insulation properties of these cellular type insulations often deteriorate with time due to the diffusion of the gases filling the voids, and the panel construction inhibits this process. Currently, with existing energy costs, the thermal conductance should not exceed 0.15 kcal/m2 h◦ C for cold stores. However, with ever-increasing energy costs this figure will have to be improved. The final quality of any insulation is not only a matter of the properties of the material itself, but of the way it is erected or fitted to the external building. Heat bridges should be avoided, e.g. those normally created by pipes and cable joints. Piping which carries low-pressure refrigerant or other liquids at low temperatures must be insulated. The provision of an efficient vapour barrier on the outside of the finished insulation with joints properly sealed is of utmost importance, as moisture vapour penetrating the insulation will form ice and gradually destroy the insulation material. A prefabricated structure results in a very short on-site erection time and this operation can be done by unskilled labour under supervision. This type of construction is therefore appropriate for remote sites where there is no skilled labour for other types of construction. In cold stores, energy is wasted due to air infiltration into the room during loading and unloading and other instances when the barrier between the cold and warm environments is removed. Air infiltration is also the main source of frost on evaporators and can lead to accidents caused by ice. Transparent PVC strip curtains are the traditional and most commonly used method of reducing infiltration. Ligtenburg and Wijjfels (1995) claim that ‘they are generally considered as unsafe, not particularly efficient, unhygienic and requiring much maintenance and it is possible that they may be banned in the future’. Vestibules or air locks and flexible, fast-opening doors, often in combination with each other, are other methods employed to reduce infiltration. However, vestibules restrict access, are difficult to fit to existing sites and can be bulky, while flexible, fast-opening doors have heavy maintenance requirements and reduce vision for forklift truck operators. Air curtains reduce infiltration without taking up as much space as vestibules and without impeding traffic. Their origin dates back to a patent applied for by Van Kennel in 1904 and they

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have been popular for around 50 years. An air curtain consists of a fan unit that produces a planar jet of air (air curtain), which forms a barrier to heat, moisture, dust, odours, insects etc. In the case of cold store air curtains, the device that produces it is usually mounted above the door, blowing the air curtain vertically down. Studies have shown the importance of setting up an air curtain to give optimal effectiveness (Foster et al., 2007). Increasing the jet velocity from its installed value (10.5 ms−1 ) to its maximum (18 ms−1 ) increased its effectiveness from 0.31 to 0.71. Most frozen fish stores will have a separate loading bay to provide for easy handling of pallets between the cold store and transport trucks. This should be refrigerated to act as a barrier to heat flow from the ambient directly into the store. The height of the loading ramp should correspond to the height of the floor of the more popularly used transport vehicles. This height is normally about 1.40 m for trucks and can be as low as 0.60 m for distribution vans. It is an increasing practice for seals to be fitted round loading bay doors to close the gap between the refrigerated vehicle and the structure to reduce heat ingress during loading and unloading. The value of produce in a cold store can be considerable; therefore, some back-up is required in case of major failure in the refrigeration plant. For instance, two smaller condensing units can be used instead of one large unit and one of these, operating on its own, may be used to hold the cold store at a reasonable temperature while the other is repaired. In larger stores, two units may be necessary to meet the refrigeration capacity required, and in this case it would not be unreasonable to have a third unit and operate any two of the three on a rotational basis, with the third unit as a standby. It is a normal practice to design a new cold store on the basis of 18 hours running/ 24 hours under full-load conditions. This allows for deterioration in the fabric of the store and the refrigeration machinery over the normally expected 20 years of operational life. In a frozen fish store the refrigerant temperature has to be lower than the required air temperature and will typically be between −25 and −35◦ C. At these temperatures frost will deposit on the coils and this results in a reduction in the heat exchange. The frost thickness built-up is, however, of less importance than ensuring the free passage of air through the evaporator coil. Regular defrosting is of great importance in the operation of a cold store. There are a number of methods available, such as hot-gas defrosting for direct expansion systems and electric defrosting. Usually defrost are controlled by a timer with the option of a manual override. Other developments include sensors which measure the frost deposit at specific locations on the cooler fins, the air flow reduction due to frost build-up or the refrigerant temperature differential across the cooler. They may be linked to a timer to ensure that auto defrosts do not occur during high refrigeration load period.

6.3.1 Bulk storage rooms Most unwrapped fish and all types of wrapped fish and fish products are stored in large air-circulated rooms. To minimise weight loss and appearance changes associated with desiccation, air movement around the unwrapped product should be the minimum required to maintain a constant temperature. With wrapped products low air velocities are also desirable to minimise energy consumption. However, many storage rooms are designed and constructed with little regard to air distribution and localised velocities over products. Horizontal throw refrigeration coils are often mounted in the free space above the racks or rails of products and no attempt is made to distribute the air around the products. Using a false ceiling or other form of ducting to distribute the air throughout the storage room can substantially reduce variations in velocity and temperature. Using air socks, it is claimed that an even air distribution can be maintained with localised velocities not exceeding 0.2 ms−1 .

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6.3.2

143

Jacketed cold stores

Cooling the walls, floor and ceiling of a store produces very good temperature control in the enclosed space with the minimum of air movement. It is especially suitable for unwrapped produce that are very sensitive to air movement or temperature fluctuations. The refrigerated jacket can be provided by embedding pipe coils in the structure or utilising a double skin construction through which refrigerated air is circulated. Although the refrigerated jacket is efficient in absorbing any heat input from the surroundings, the lack of air circulation within the enclosed space means that heat removal from the product is very limited. Care must therefore be taken to (a) attain the desired storage temperature throughout the product before storing, (b) minimise any heat loads produced during loading and unloading and (c) provide the supplementary refrigeration required for any products which respire.

6.4 SPECIFICATION AND OPTIMISATION OF COLD STORES The purpose of a frozen cold store is to maintain the temperature of a previously frozen product within a small control band. A few degrees reduction in a storage or display temperature can substantially increase the high-quality storage life of many fish products. In contrast a few degrees rise in temperature can subsequently reduce the storage life and quality of the material being stored. Despite the importance of refrigeration, in our experience so many of the problems in the fish cold-chain are caused by poorly specified refrigeration systems, leading to many problems for both users and suppliers. The poor performance of a new refrigeration system can often be chased back to a poor, non-existent or ambiguous process specification. In older systems it is often due to a change in use that was not considered in the original specification. There are three stages in obtaining a food refrigeration system that works. 1. Determining the process specification, i.e. specifying exactly the condition of the fish or fish product when it enters the system, how long you would like it to remain in the system and what state it is required to be in when it exits; 2. Drawing up the engineering specification, i.e. turning processing conditions into terms that a refrigeration engineer can understand, independent of the food process; and 3. The procurement of the total system. The first task in designing a plant is therefore the preparation of a clear specification by the user of how the facility will be used now, and in the foreseeable future. In preparing this specification, the user should consider the views of all parties concerned: these may be officials enforcing legislation, customers, other departments within the company and engineering consultants or contractors – but the ultimate decisions taken in forming this specification are the users alone. The process specification must include, as a minimum, data on the product(s) to be handled, in terms of size, shape and throughput. The maximum capacity must be catered for and the system should also be specified to operate economically at all other throughputs. Defining the capacity is not a trivial task; the FAO list the following nine factors as affecting the capacity of a frozen cold store for fish: 1. Loading density of the products; 2. Proportions of different products stored; 3. Stacking method used;

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4. 5. 6. 7. 8. 9.

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Stacking arrangement to meet access requirement; Separation of products required to suit customer or product requirements; Mixture of pallet sizes; Handling system used and space required for manoeuvring; Stacking height; and Space required for coolers and airflow distribution.

The range of temperature requirements for each product must also be clearly stated. If it is intended to minimise loss during frozen storage, it is useful to quantify at an early stage how much extra money can be spent to save a given amount of weight. All the information collected so far, and the decisions taken, will be on existing production. Another question that needs to be asked is, ‘Will there be any foreseeable changes in the use of the refrigeration system in the future?’ Frozen storage is just one operation in a sequence of operations. It influences the whole system and interacts with it. An idea must be obtained of how the system will be loaded, unloaded and cleaned, and these operations must always be intimately involved with those of the rest of the operation. There is often a conflict of interest within a frozen storage area. In practice the store is often used as a marshalling yard for sorting raw products prior to canning. If it is intended that this operation is to take place in the frozen store the design must be made much more flexible in order to cover the conditions needed in a marshalling area or a refrigerated store. If a frozen store will sometimes be used to freeze fish products then this will need to be taken into account. In the case of a batch and semi-continuous operation, holding areas will be required at the beginning and end of the process in order to even out flows of material from adjacent processes. The time available for the process will be in part dictated by the space that is available; a slow process will take more space than a fast process, for a given throughput. Other refrigeration loads in addition to that caused by the product also need to be specified. Many of these, such as infiltration through openings, the use of lights, machinery and people working in the refrigerated space, are all under the control of the user and must be specified so that the heat load given off by them can be incorporated in the final design. Ideally, all the loads should then be summed together on a time basis to produce a load profile. If the refrigeration process is to be incorporated with all other processes within a plant, in order to achieve an economic solution, then the load profile is important. The ambient design conditions must be specified. This must include all the temperatures of the air and surfaces adjacent to the refrigerated area and refrigerated equipment and the temperatures of the ambient to which heat will ultimately be rejected. In stand-alone refrigerated processes this will often be the wet and dry bulb temperatures of the outside air. If the process is to be integrated with heat reclamation then the temperature of the heat sinks must be specified. Finally the defrost regime should also be specified. There are times in any process where it is critical that a defrost does not take place and that the coil is cleared of frost before commencing this part of the process. The end user should specify all the above requirements. It is common practice throughout the food industry to leave much of this specification to refrigeration contractors or engineering specialists. Often they are in a position to give good advice on this. However, since all the above are outside their control, the end user, using their knowledge of how well they can control their overall process, should always take the final decision. The aim of drawing up an engineering specification is to turn the user’s needs into a specification that any refrigeration engineer can then use to design a system. The first step in this process is iterative. First, a full range of time, temperature and air velocity options must be assembled for each

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specification covering the complete range of each product. Each must then be evaluated against the user’s requirements. If they are not a fit then another option is selected and the process repeated. If there are no more options available there are only two alternatives; either the standards must be lowered, recognising that in doing so the refrigeration specifications will not be met, or the factory operation must be altered. A full engineering specification will typically include the environmental conditions within the refrigerated enclosure, air temperature, air velocity and humidity; the way the air will move within the refrigerated enclosure; the size of the equipment; the refrigeration load profile; the ambient design conditions and the defrost requirements. The final phase of the engineering specification should be drawing up a schedule for testing the engineering specification prior to handing over the equipment. This test will be in engineering and not product terms. The specification produced should be the document that forms the basis for quotations and finally the contract between the user and his contractor and must be stated in terms that are objectively measurable once the chiller/freezer is completed. Arguments often ensue between contractors and their clients from an unclear, ambiguous or unenforceable specification. Such lack of clarity is often expensive to all parties and should be avoided. In view of the increasing demand for energy and the escalating costs of energy from all sources, energy management and energy conservation are becoming increasingly important in all industries and obviously also in the food systems. Energy consumption obviously has to be considered at the planning and design stages of a cold store. Large savings can be made by careful selection and assembly of components. Choosing efficient evaporator fans with the correct mass air flow and air throw for the store dimensions and optimising the insulation thickness taking relevant location conditions into account can show considerable savings. Heat pumps can be used to utilise condenser heat for heating purposes, e.g. hot water for cleaning or heating. All buildings should be of a light colour. The loading dock should preferably be enclosed. This is just to mention a few measures to be taken. Today, most of the relevant actions are taken in the cold store design as long as experienced consultants are used. The measures to be taken from an operational point of view range from proper control of lighting and air conditioning to the proper running and maintenance of the engine room.

6.5

THAWING

Frozen fish as supplied to the industry ranges in size and shape, although much of it is in blocks packed in boxes. Thawing is usually regarded as complete when the centre of the block has reached 0◦ C; the minimum temperature at which the fish can be filleted or cut by hand. Lower temperatures (e.g. −5 to −2◦ C) are acceptable for fish that is destined for mechanical chopping, but such fish is ‘tempered’ rather than thawed. The two processes should not be confused because tempering only constitutes the initial phase of a complete thawing process. Thawing is often considered as simply the reversal of the freezing process. However, inherent in thawing is a major problem that does not occur in the freezing operation. The majority of the bacteria that cause spoilage or food poisoning are found on the surfaces of fish. During the freezing operation, surface temperatures are reduced rapidly and bacterial multiplication is severely limited, with bacteria becoming completely dormant below −10◦ C. In the thawing operation these same surface areas are the first to rise in temperature and bacterial multiplication can recommence. On large objects subjected to long uncontrolled thawing cycles, surface spoilage can occur before the centre regions have fully thawed.

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Most systems supply heat to the surface and then rely on conduction to transfer that heat into the centre of the fish. A few use electromagnetic radiation to generate heat within the fish. In selecting a thawing system for industrial use, a balance must be struck between thawing time, appearance end bacteriological condition of product, processing problems such as effluent disposal and the capital and operating costs of the respective systems. Of these factors, thawing time is the principal criterion that governs selection of the system. Appearance, bacteriological condition and weight loss are important if the material is to be sold in the thawed condition but are less so if the fish is for processing. The design of any thawing system requires knowledge of the particular environmental or process conditions necessary to achieve a given thawing time, and the effect of these conditions on factors such as drip, evaporative losses, appearance and bacteriological quality. The process of freezing a high water content material such as fish takes place over a range of temperatures rather than at an exact point, because as freezing proceeds the concentration of solutes in the fish fluid steadily increases and progressively lowers the freezing temperature. Thawing simply reverses this process. Thawing time depends on factors relating to the product and the environmental conditions that include:

1. 2. 3. 4. 5. 6.

Dimensions and shape of the product, particularly the thickness; Change in enthalpy; Thermal conductivity of the product; Initial and final temperatures; Surface heat transfer coefficient; Temperature of the thawing medium.

Thermal conductivity has an important effect in thawing. The conductivity of frozen fish muscle is three times that of the thawed material. When thawing commences, the surface rises above the initial freezing point. Subsequently, an increasing thickness of poorly conducting material extends from the surface into the foodstuff reducing the rate of heat flow into the centre of the material. This substantially increases the time required for thawing.

6.5.1

Thawing methods

There are two basic methods of thawing: thermal and electrical. Thermal methods are dependent upon conventional heat conduction through the surface. Electrical methods on the other hand employ heat generation inside the product. There is no simple guide to the choice of an optimum thawing system (Table 6.2). A thawing system should be considered as one operation in the production chain. It receives frozen material, hopefully, within a known temperature range and of specified microbiological condition. It is expected to deliver that same material in a given time in a totally thawed state. The weight loss and increase in bacterial numbers during thawing should be within acceptable limits, which will vary from process to process. In some circumstances, e.g. direct sale to the consumer, the appearance of the thawed product is crucial, in others it may be irrelevant. Apart from these factors the economics and overall practicality of the thawing operation, including the capital and running costs of the plant, the labour requirements, ease of cleaning and the flexibility of the plant to handle different products, must be considered.

Design and operation of frozen cold stores Table 6.2

Conduction systems

147

Advantages and disadvantages of different thawing systems.

Air

Advantages

Disadvantages

Easy to install: can be adapted from chill rooms

Very slow, unless high velocities and high temperatures are used, when there can be weight loss, spoilage and appearance problems

Low velocity systems retain good appearance Water

Faster than air systems

Effluent disposal Deterioration in appearance and microbiological condition Unsuitable for composite blocks

Vacuum heat

Fast

Deterioration in appearance

Low surface temperatures

High cost

Very controllable

Batch size limited

Easily cleaned High pressure

Fast

Not commercially available at present

Microwave/infra red

Very fast

Resistive

Fast

Problems of contact on irregular surfaces

Ultrasonic

Fast

Not commercially available at present

Reduces microorganisms Electrical systems

Problems of limited penetration and uneven energy absorption. Can cause localised ‘cooking’ High cost

Thermal Air: Air is used in the vast majority of thawing/tempering applications. Use of still air is limited to thin products, otherwise thawing times are excessively long. Although little or no equipment is needed, considerable space is required to lay out individual items of product. Moving air is more commonly used, providing more rapid heat transfer as well as improved control of temperature and humidity. Two-stage air thawing with high initial air temperature followed by a second stage at an air temperature below 10◦ C has also been used. The duration of the high-temperature stage is limited to 1 or 2 hours to avoid excessive bacterial growth, but the increase in heat input during this time considerably reduces the overall process time. Immersion: Immersion in liquid media allows much more rapid heat transfer, especially if pumped or agitated to avoid temperature stratification in the liquid and grouping together of products. Thawing times are therefore greatly reduced. Practical limitations are that boxes and other packaging (unless vacuum pack or shrink wrap) must be removed before immersion, bulk blocks are liable to break up, leaching of product surfaces can lead to poor appearance and frequent changing of water for hygiene reasons requires disposal or treatment of large quantities of effluent. Plate: Plate thawing between metal plates through which warm liquid is piped. The plates and product may also be immersed in water to improve thermal contact between them. Shape is important for reasonable contact with the flat plates, although immersion helps by filling gaps. If immersion is used, frequent water changing is required to prevent bacterial accumulation.

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Vacuum: Vacuum thawing transfers latent heat of condensation of steam onto product surfaces at low-pressure and temperature. For example, if a pressure of 1704 Nm−2 is maintained, steam can be generated at 15◦ C and will condense at this temperature onto the frozen product surfaces. This ensures that although large amounts of latent heat are added, the product will not rise above 15◦ C. The process is rapid, but evacuation to sub-atmospheric pressure restricts it to batch operation. More effective for thin products where the heat released at the surface is quickly conducted through the product. High pressure: High pressure decreases the phase change temperature of pure water (down to −21◦ C at 210 MPa). The lowering of the melting point allows the temperature gap between the heat source and the phase change front to increase, and thus enhances the rate of heat flux (IIR, 2006; Rouill´e et al., 2002). The pressure is released when the food temperature is a little above 0◦ C. High-pressure thawing has been applied experimentally to fish and shellfish (Rouill´e et al., 2002). There is some evidence that the high pressure has the additional benefit of reducing the number of microorganisms (IIR, 2006; Rouill´e et al., 2002).

Electrical Resistance (50–60 Hz): passage of current creates heating effect (ohmic heating). Electrical contacts are required and product structure must be uniform and homogeneous, otherwise the path of least resistance will be taken by the current, resulting in uneven temperatures and runaway heating. Frozen foods do not readily conduct electricity at low temperatures, but this improves at higher temperatures, so uniformity of initial temperature distribution is also important to avoid runaway heating. Dielectric: this is split into two frequency bands, radio frequency and microwave. The first uses more typical electrical techniques, with conductors, electrodes etc. The second relies more on electromagnetic wave technology, with waveguides to ‘beam’ the waves into a cavity. Radio frequency (3–300 MHz): application of alternating electric e.m.f. using electrodes. Product requirements are similar to resistance methods, uniform structure, homogeneity, and uniformity of temperature distribution. The field is created between two or more electrodes, but the product need not be in direct contact with them. Conveyorised systems have been applied to thawing of fish and offal, in some cases using water surrounding the material to aid temperature uniformity. Microwave (900–3000 MHz): electromagnetic waves directed at the product through waveguides without the use of conductors or electrodes. Potentially very rapid, the application is limited by thermal instability and penetration depth. Instability results from preferential absorption of energy by warmer sections and by different ingredients, such as fat. Warmer sections may be present at the start of the process, e.g. the surface temperature may be warmer than the middle, or they may be produced during the process, such as energy being absorbed at the surface rather than penetrating all of the product. In the extreme, such warming can lead to some parts of the food being cooked while others remain frozen. These problems, as well as the capital cost of equipment, have greatly limited commercial use. Attempts to avoid runaway heating have involved low power (and hence longer duration) microwaving, cycling of power on and off to allow equalisation periods and cooling of surfaces with air or liquid nitrogen. Penetration depth depends upon temperature and frequency, being generally much greater at frozen temperatures, and greater at lower frequencies. Ultrasonic: In some work ultrasound has been merely used to assist heat transfer during immersion thawing. However, research has shown that ultrasound is more highly attenuated in frozen meat than in unfrozen tissue and that the attenuation increases markedly with temperature, reaching a maximum near the initial freezing point of the food (Miles et al., 1999). The ultrasound

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attenuation-temperature profile therefore appears to be better suited to producing stable rapid thawing than microwave. Miles et al. (1999) have demonstrated that using 300 kHz ultrasound at an intensity of 1 Wcm−2 , a 15-cm-thick block of meat can be thawed in less than 1 hour.

6.5.2

Thaw rigor

Thaw rigor can be a particular problem with fish since much fish is frozen at sea immediately after catching and before rigor has completed. All rigor will continue during frozen storage; it will do so at a very slow pace and may not have completed before the fish is further processed. If it is known that a proportion of the raw material may still be in rigor, then conditioning at −12 to −15◦ C for several days, or controlled slow thawing can alleviate this problem (IIR, 2006).

6.6 CONCLUSIONS Maximum storage life of fishery products can be obtained by employing the following procedures: Select only high-quality fish for freezing; Freeze fish immediately after processing or packaging; Use tightly fitting moisture and oxygen impermeable packaging materials; Glaze frozen fish prior to packaging; Put fish in frozen storage immediately after freezing and glazing, if required; Store frozen fish at −26◦ C or lower; and Renew glaze on round, unpackaged fish as required during frozen storage. Although a great deal has been written on the frozen storage life of different fish the underlying data are backed up by a relatively small number of controlled scientific experiments. Many of the scientific data date back to the time when fish was stored either in unwrapped or in wrapping materials that are no longer used. It is not surprising when we consider the changes in packaging and handling methods over the last century that there is a considerable scatter in data on storage lives for similar products. In recent years energy conservation requirements have caused an increased interest in the possibility of using more efficient storage temperatures than have been used to date. Researchers such as Jul have questioned the wisdom of storage below −20◦ C and have asked whether there is any real economic advantage in very low temperature preservation. There is a growing realisation that storage lives of several foods can be less dependent on temperature than previously thought. Since research has shown that fish and shellfish often produce non-linear time-temperature curves there is probably an optimum storage temperature for a particular product. Improved packing and preservation of products can also increase storage life and may allow higher storage temperatures to be used. It is interesting to note, finally, that there appears to have been very little research into assessing the effect of freezing and frozen storage of fish and shellfish on the final quality of canned fish and shellfish produced from previously frozen raw materials (Aubourg, 2001). In one of the few studies on the subject, Aubourg and Medina (1997) concluded that sardines should not be kept for more than 4 months at −18◦ C to maintain acceptable nutritional and sensory properties in the final canned product.

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REFERENCES ASHRAE (1998) ASHRAE Handbook: Refrigeration. American Society of Heating, Refrigerating and AirConditioning Engineers, Atlanta, US. ASHRAE (2006) ASHRAE Handbook – Refrigeration. American Society of Heating, Refrigerating and AirConditioning Engineers, Inc., Atlanta, GA. Aubourg, A.P. (2001) Review: Loss of quality during the manufacture of canned fish products. Food Science and Technology International, 7, 199–215. Aubourg, A.P. and Medina, I. (1997) Quality differences assessment in canned sardine (Sardina pilchardus) by detection of fluorescent compounds. Journal of Agricultural and Food Chemistry, 45, 3617–3621. Bøgh-Sørensen, L. (1984) The TTT-PPP concept. In Thermal Processing and Quality of Foods, edited by Zeuthen, P., Cheftel, J.C., Eriksson, C., Jul, M., Leniger, H., Linko, P., Varela, G. and Vos, G., pp. 511–521. Elsevier Applied Science London, UK. Codex Alimentarius Commission (1980) Recommended International Code of Practice for Frozen Fish. CAC/RCP 16–1978. FAO and WHO, Rome, Italy. Commission of the European Community (1984) Proposal for a council directive on the approximation of the Laws of the Member States relating to quick-frozen foodstuffs for human consumption. COM(84)489final. Foster, A.M., Swain, M.J. and James, S.J. (2007) Two and three dimensional CFD models of the effectiveness of an air curtain used to restrict cold room infiltration. Applied Mathematical Modelling, 31, 1109–1123. Gomezbasauri, J.V. and Regenstein, J.M. (1992) Processing and frozen storage effects on the iron content of cod and mackerel. Journal of Food Science, 57(6), 1332–1336. Gortner, W.A., Fenton, F., Volz, F.E. and Gleim, E. (1948) Effect of fluctuating storage temperatures on quality of frozen food. Industrial Engineering Chemistry, 40, 1423–1426. Graham, J. (1984) Planning and Engineering Data 3. Fish Freezing. FAO Fisheries Circular No. 771, Food and Agriculture Organization of the United Nations. Hedges, N. and Nielsen, J. (2000) The selection and pre-treatment of fish. In Managing Frozen Foods, edited by Kennedy, C.J., Chapter 6, pp. 95–110. Woodhead Publishing Limited, Cambridge. Heen, E. (1981) Developments in chilling and freezing of fish. Advances in the Refrigerated Treatment of Fish, Meeting of IIR Commissions C2, D1, D2, D3, Boston, USA, pp. 41–47. IIR (2006) Recommendations for the Processing and Handling of Frozen Foods. IIR 177 bouelvard malesherbes, F-75071 Paris, France. Johnston, W.A., Nicholson, F.J., Roger, A. and Stroud, G.D. (1994) Freezing and Refrigerated Storage in Fisheries. FAO Fisheries Technical Paper – 340, Food and Agriculture Organization of the United Nations. Lavety, J. (1991) Physio-chemical problems associated with fish freezing. In Food Freezing: Today and Tomorrow, edited by Bald, W.B., Chapter 10, pp. 123–131. Springer Series in Applied Biology, Springer-Verlag, London. Ligtenburg, P.J.J.H. and Wijjfels, D.J. (1995) Innovative air curtains for frozen food stores. Proceedings of the International Congress of Refrigeration, 420–437. Miles, C.A., Morley, M.J. and Rendell, M. (1999) High power ultrasonic thawing of frozen foods. Journal of Food Engineering, 39, 151–159. Myrseth, A. (1985) Planning and Engineering Data 2. Fish Canning. FAO Fisheries Circular No. 784, Food and Agriculture Organization of the United Nations. Rouill´e, J., LeBail, A., Ramaswamy, H.S. and Leclerc, L. (2002) High pressure thawing of fish and shellfish. Journal of Food Engineering, 53, 83–88. Sotelo, C.G., Pineiro, C. and Perezmartin, R.I. (1995) Denaturation of fish proteins during frozen storage – role of formaldehyde. Zeitschrift Fur Lebensmittel-Untersuchung Und-Forschung, 200(1), 14–23.

7

Packaging formats for heat-sterilised canned fish products

Bev Page

7.1

OVERVIEW OF THE BASIC MATERIALS USED FOR HEAT-STERILISED FISH PACKAGING

Most packages for heat-sterilised fish products are formed from steel-based materials (packaging steels) or aluminium. Within these metals most of the containers are made as shallow seamless cans many of which have fully printed bodies with ends to match. There has been a great expansion of fish canning in Morocco as sardines have moved south and major can makers have set up in that country to be near to their filler customers. Plastic pouches have been introduced in recent years to provide another packaging format for certain product lines. These present the product in a very different way from metal cans and have the added advantage of being microwaveable. Glass containers for heat-sterilised fish are used only for selected products – particularly where there is a benefit in being able to see the product in the container.

7.2 7.2.1

METAL CANS FOR HEAT-STERILISED FISH PRODUCTS Overview of the world market for metal cans

The total world market for metal containers is estimated at 400 billion units per annum.1 Within this, beer and beverage cans are 254 billion, food cans are 75 billion and aerosol cans are 12 billion. The remainder are processed (liquid coffee, tea, sports drinks etc.) or non-carbonated drinks and general line cans. The largest markets by continent are: North America (beer and beverage 110 billion, food and general line 29 billion, aerosol 3.9 billion) and Europe (beer and beverage 45 billion, food and general line 27 billion, aerosol 4.4 billion); and Asia Pacific (beer and beverage 48 billion, processed drinks 6.1 billion, food and general line 10 billion) The worldwide market for seafood cans, contained within the above totals, is estimated at 13 billion cans.

1

Sayers Publishing Group – The Canmaker Conference, October 2007.

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7.2.2

Metal can and end designs

There are a number of different can-forming processes, some of which are capable of making cans of similar shapes. However, regardless of the particular can-forming process used, the shape of a metal container also has a great effect on its cost and physical performance. For most metal food containers the cost of the metal itself is 50–70% of the total container cost. The amount of metal in any particular container is therefore the most significant cost item and this is related to the metal thickness and the surface area purchased to make it, which includes process waste. In can design, metal thickness is determined by the need for physical performance in handling, heat processing and storage of the filled container. Surface area is determined by the volume contents and the chosen shape of the container. For ease of manufacturing, handling, filling and closing, many food cans have a circular horizontal cross section. However, where whole fish are packed, shallow non-round (rectangular, oval etc.) horizontal cross-sectional containers may be used with dimensions specified to suit the individual product. For different physical performance, cost and product uses, and taking the example of circular cans, these may vary from shallow (height less than diameter) to tall (height greater than diameter). For non-round cans read width/length for diameter. Figure 7.1 shows the vertical cross section of typical circular cross-sectional metal containers used for packing heat-sterilised fish products. These may be divided into the following three categories:

r r r

Shallow cans – having height significantly less than the diameter (width/length); Short cans having height similar to the diameter; and Tall cans having height greater than the diameter

It will be shown later in Section 7.2.9 that height-to-diameter ratios are important in helping to decide which metal forming process is the most practical and economic to use. In Figure 7.1

1

Two-piece DRD short can

2

Two-piece single draw shallow can

Three-piece tall can with straight side wall and beads

Two-piece DWI or DRD tall can with side wall beads

4

Three-piece short can

3

Three-piece tall can with necked-in base and side wall beads

5

(shown as circular open top cans without filler’s end fitted) Three-piece = Side seam welded DRD = Seamless draw/redraw DWI = Seamless draw and wall iron Fig. 7.1

Processed food/fish can outlines.

6

Packaging formats for heat-sterilised canned fish products

153

examples 4, 5 and 6 all have the same volume capacity. Examples 4 and 5 both have external base diameters that permit filled cans to be stacked one above the other. There are two basic methods used for constructing three-dimensional containers from flat sheet metal. A three-piece container is made from a pre-cut rectangular flat sheet of metal which is rolled into a cylinder to form the body. The body seam is electrically welded and following this a base end is fixed on by the can maker. After filling, a second end is fitted to the top of the can to make the ‘three’ pieces of metal. A two-piece container is also made from a flat piece of metal but its shape is either round or rectangular depending on the shape of the finished can. Using a sequence of metal drawing techniques the flat metal is formed into a three-dimensional seamless can body with integral base and with an open top. After filling, an end is fixed to the top of the can to make ‘two’ pieces of metal. Details of these processes are shown in Section 7.2.5. Figure 7.1 shows typical cross sections of round cans used for heat processed foods. Example 4 shows drawn and wall ironed (DWI) cans which have the body wall thinned after initial shaping to provide tall lightweight cans. These cans are not currently used for fish products. Can sidewalls may be straight (non-tapered) or tapered (conical), although only one of the can forming processes (single or multiple draw) is capable of making tapered walls. For heat processed fish products the taper wall feature is very important where empty containers have to be transported over vast distance by land to reach the often remote filling and heat processing stations. This feature permits the empty formed cans to be nested one inside the other to concentrate the mass into the smallest volume. For example, straight wall cans which cannot be nested may fill the whole space volume capacity in a transport container but may only have a mass equal to say 10–20% of the container’s load capacity. Equivalent nested tapered containers whilst filling the volume capacity would also have a mass approximately the same as the load capacity. The transport cost benefits of empty tapered containers are only of benefit to the total cost of the filled product where very long transport distances are involved as the savings from this are likely to be offset by increased cost of can making and times for empty can handling and packing. Tapered containers are also referred to as conical and may be circular, oval or rectangular in cross section. They may also be shallow, short or tall cans as defined above in this section. Typically, most tapered containers for fish products are used in Alaska (salmon) and northern Scandinavia (sardines etc.) where land distances between can maker and filler are very great. For products like salmon and tuna use of tapered containers has the added benefit of allowing the product to be removed from the opened can in one piece. Figure 7.2 shows typical cross sections of round tapered cans for salmon, examples 7 and 8 and rectangular straight and tapered wall cans used for sardines etc. shown as example 10. Tall circular section cans 73 mm diameter and above are usually beaded to withstand the external pressure on the can body from within the heating processing chamber. As it is not technically possible to make beads in the sidewalls of tall two-piece tapered cans it is necessary to supply these tapered cans with heavy gauge walls to prevent implosion during heat processing. These cans are therefore relatively more expensive to make than the equivalent non-tapered cans. However, because of their nestability, they are still less costly to transport over very long distances. Bowl-shaped containers which are made by technology similar to that used for forming tapered cans offer an alternative way of presenting the fish product as a meal with other ingredients. Figure 7.2, example 9, shows a typical cross section of this type of can. Food cans require an aperture with the full cross section of the container through which to remove the product. Historically food cans have required a can-opening tool to remove the plain lid. In more recent years full-aperture easy-open ends have been developed on the basis of designs originally used for drink products. Whether plain or easy-open ends are used, the end panel for virtually all food cans is mechanically seamed on to produce a double seam which is capable of withstanding all

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10 Conical

9

Club/Dingley cross sections

Salmon

DRD Bowl

Conical DRD

Straight wall

7 Plan views of overall dimensions after seaming

8

Salmon Conical DRD

Club 104 x 60

Dingley 105 x 76

(shown as open top can cross sections without filler’s end) Fig. 7.2

Processed fish can outlines.

the heat processing cycles in use. Heat sealing of foil lids onto metal containers also withstands full heat process cycles although many of these require overpressure to be applied to the retort to reduce the expansion load on the foil membrane. New flexible lidding materials are however becoming available that will withstand the full cycle in conventional (non-overpressure) retorts. In recent years the peelable membrane end has been introduced as an alternate form of easyopening end. This is made by cutting out the centre panel of a plain metal end (non-easy-open) and heat sealing a flexible aluminium lid over the aperture. This provides an end which is simple to open yet has the benefit of being mechanically seamed onto the flange of the can body by the filler. Metal can bodies for processed fish products are normally decorated by the application of print to the flat sheet prior to metal forming or by application of paper labels to the can after forming. An alternative method of providing printed information about the product and often used by canners of sardines etc. is to pack an unprinted metal can into an individual printed carton. Tall cans with beaded sidewalls are not normally printed but will have paper labels attached. Can ends made from rigid sheet metal may also be printed in a flat sheet form prior to forming the final end profile. Flexible aluminium lidding (for peelable membrane ends) is printed while the metal is in coil form. Tables 7.1 and 7.2 provide dimensions of heat-sterilised cans for fish products in various formats. The cans shown here are some of those in current production by a number of different suppliers. This is not a definitive list but does indicate the great range of sizes that are in use particularly in the two-piece round (straight side) format.

7.2.3

Metal can and end performance requirements

Metal packages for food products must perform the following basic functions if the contents are to be delivered to the ultimate consumer in a safe and wholesome manner and satisfy current environmental requirements. In addition, these functions must continue to be performed satisfactorily until well after the end of the stated shelf life period.

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Table 7.1

Table of fish can dimensions.

Type

Material

Capacity (mL)

Length (mm)

Width (mm)

Height (mm)

Product

Club Club Club Club 1/ Club 4 Club

Al/Tpl Al/Tpl Al/Tpl Al/Tpl Al/Tpl Al/Tpl

85 90 97 120 125 132

104 104 104 104 104 104

60 60 60 60 60 60

21.2 22 24 25 29 30

Sardines etc. “ “ “ “ “

Dingley Dingley 1/ Dingley 4 Dingley

Al/Tpl Al/Tpl Al/Tpl Al/Tpl

75 100 112 125

105 105 105 105

76 76 76 76

16 19 21.5 23

Sardines etc. “ “ “

1/ 2 1/ 2

Al/Tpl Al/Tpl Al

200 212 190

148 155 194

81 61 58

25 30 25

Herrings Kippers

Two-piece non-round (conical or straight side)

Hansa Oblong Langoval

Two-piece round (conical) Type

Material Al Al Al ECCS ECCS Al Al

Capacity (mL)

Diameter (major) (mm)

Height (mm)

Product

64/62 73 73 73 85/83 86 99 99

15 32 39 110 50 45.1 31.5 35

Crab/lobster

103 127 418 213 212 185 212

Salmon Salmon

Three-piece round Type

ET ET

r r r r r r r r

Material

Capacity (g)

ECCS ECCS ECCS ECCS ECCS ECCS

155 80 418 400 400

Diameter (mm)

Height (mm)

Product

53 65 65 73 73 85

85 30 100 110 110 82

Pilchards Crab/lobster Clams Pilchards Tuna Tuna

Preserve and protect the product; Resist any chemical actions of the product; Withstand the handling and processing conditions; Withstand the external environment conditions; Have the correct dimensions and the ability to be practically interchangeable with similar products from other supply sources (when necessary); Have the required shelf display properties at the point of sale; Give easy opening and simple/safe product removal; and Be constructed from fully recyclable raw materials.

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Table 7.2

Table of fish can dimensions. Two-piece round (straight side)

Type

Material

Capacity (mL)

Al Al Al

103 115

Rounded

Al Al Al

1/ 2

Al/Tpl

round

Height (mm)

Product

64 73 78

34 31.5 32

Tuna

156 205 225

86 86 90

37 42.3 40

245

90 61 65 73 73 73 73 83 83 83 83 99 99 99 99 99 99 99 99

44 33 40 34 34.5 52 52.5 40 42 45 56 27.5 38.5 44 50.5 55 57 57.5 60

ECCS ECCS

125 126 200 202

ECCS 200 ECCS Tpl Tpl Tpl 290 Tpl ECCS 400 404 425 One round

Tpl ECCS

490

Diameter (mm)

120 153

49 80

Tuna Tuna Salmon

Salmon Shrimp/crab

Tuna

Tuna

Most filled food containers for ambient shelf storage are subjected to heat processing to prolong the shelf life of the product. This will normally provide a shelf life in excess of three years. The heat process cycles used to achieve this are particularly severe and the filled containers must be specifically designed to withstand these conditions of temperature and pressure cycles in a steam/water atmosphere. During the early part of the heating cycle, the external pressure on the container is greater than that on the inside. As the temperature in the container increases to that of the external heating medium the internal pressure rises above that on the outside. The can body and end(s) must be capable of withstanding these various pressure differentials. Depending on the shape of the container say tall, cylindrical or shallow rectangular these pressures will affect different parts of the can. Following heat processing, when the can temperature has returned to ambient, there will normally be a negative pressure in the can. Under these conditions, the food product itself does not provide any strength to the can to resist external loads, although this is normally only an issue where tall cans are used, i.e. those where the height is greater than the diameter (see Section 7.2.2). Side wall beads are added to thin wall tall cans to prevent implosion during the early stage of heat processing. Addition of side wall beads has the immediate effect of reducing the axial compression load resistance of the can body therefore in practice it is necessary to reach a compromise where both strength criteria are satisfied.

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The centre panels of food can ends have circumferential beads added to provide flexibility. This allows the panel to move and so minimise the differential pressure during the heat process. When ambient conditions are reached after processing, the centre panel is designed to have returned to its original position (that prior to the start of heat processing). When a metal container is specified by the can filler, one of the main requirements is for the filled can and end to have sufficient strength to withstand heat processing and subsequent handling throughout the distribution chain to the final consumer. While the overall dimensions of the container are clearly important for many reasons, the detailed metal thickness and mechanical properties are not of themselves critical pieces of information for the filler provided the container performs to specification. However, where can bodies and ends are purchased from different suppliers, to preserve practical interchangeability and mechanical seam integrity, more dimensional information is required. Resistance to chemical actions between the metal of the container and the product packed or the external environment is provided, when necessary, by the application of inert organic coatings to the surfaces of the metal (see Section 7.2.8).

7.2.4 Metals used in can and end manufacture Both steel and aluminium are used for metal container and closure construction for heat-sterilised fish products. These are both relatively low cost materials which are non-toxic, have adequate strength and are capable of being work hardened. Work hardening is the process of cold rolling metal to reduce its thickness resulting in an increase in hardness and tensile strength. The corrosion resistant properties of steel are improved by applying thin metallic coatings to the steel substrate. Aluminium is used in its nearly pure form. For both steel- and aluminium-based packaging for fish products organic coatings/films are applied to provide inert barriers between product and packaging and, when necessary, between packaging and the external environment.

Steel for packaging Iron is the fourth most abundant element and the refining of iron to become steel, by removing many of its impurities, is a complex process to produce what is a very complex material. This very complexity allows steel to be made with an almost unlimited number of differing properties and the metal packaging industry is able to use a number of these to considerable benefit. In the main, can and end makers are looking for soft, low temper, metal which is easy to form into deep drawn cans or at the other extreme stiff, high temper, metal from which to make high-performance can ends that will withstand food-processing conditions without buckling. Iron ore, coke and limestone are continuously fed into the top of a blast furnace (operating at about 1000◦ C/1832◦ F) and liquid iron is tapped periodically from its base. This is transferred to a steel making plant where steel scrap is added. Oxygen is then blown into the liquid to burn out the impurities and reduce the carbon content. After the addition of alloying elements the metal is prepared for casting into slabs of approximately 20 tonnes each by a process of continuous casting. After reheating the slabs to the required temperature, they are reshaped to the width required by the customer in a roughing mill and then rolled and coiled, while still hot, to a thickness of 1–4 mm. After cooling, the coils are cleaned and cold rolled through five consecutive sets of rollers (five-stand mill) to very near the finished thickness. Following this cold working, the metal has become too hard for use as a packaging material and must be softened by heating in an annealing furnace. The metal is now ready for further cold rolling to produce the final thickness and tensile properties. The steel at this point is called blackplate.

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‘Tinmill products’ is the generic title given to all steel-based products used for packaging, whether or not the steel is coated with tin or other metallic element.

r r r

‘Blackplate’ is steel without any additional metallic coating; ‘Tinplate’ is steel with a coating of tin electrolytically deposited on both sides; and ‘Electrolytic Chromium/Chromium Oxide-coated steel’ (ECCS), also referred to as ‘Tin free steel’ is steel with a coating of chromium metal and chromium oxide electrolytically deposited on both sides.

Blackplate may be used for container construction but only to pack non-chemically active products such as oils, waxes and grease. Tinplate is created by electrolytically coating blackplate with a thin layer of tin. The tin is coated on both sides of the plate in thickness to suit the internally packed product and the external environment. Different thicknesses may be applied to each side of the plate. Tin, plated in sufficient thickness, provides excellent corrosion resisting properties to steel. The tin surface also assists in providing good electrical current flow during side seam welding processes. Tin-free steel, also referred to as ECCS, is created by electrolytically coating blackplate with a thin layer of chrome/chrome oxide. This must then be coated with an organic material to provide a complete corrosion resistant surface. The metallic layer of ECCS provides an excellent key for adhesion of liquid coatings or laminates to the surface. ECCS is usually marginally less expensive than tinplate. However, being a matt surface, after coating with clear lacquer, it does not provide a reflective surface like tinplate. ECCS in its standard form is not suitable for welding without prior removal of the chrome/chrome oxide layer. The Japanese steel makers have developed modified tin-free metallic coatings for steel which do permit satisfactory welding of this material. For all fish products it is necessary to apply an organic coating (initially in liquid form) to the inside surfaces of the tinplate container to provide an inert barrier between the metal and the product packed. This barrier acts to prevent chemical action between the product and the container and to prevent taint or staining of the product by direct contact with the metal also dissolution of metal into the product (see Section 7.2.8). As an extension to the steel making and finishing operations some tinplate makers provide tinplate and ECCS with plastic coatings either laminated to or hot-melt extruded onto the metal surface. The addition of these protective films eliminates the need for liquid coating to be applied. As well as giving chemical protection, these films improve the draw qualities of the underlying steel allowing smoother and deeper drawn cans to be made.

Aluminium for packaging Aluminium is the third most abundant element and the ore from which it is extracted is bauxite. This contains ores of other metals as well and the aluminium oxide (alumina) is first extracted from the mix before the smelting operation commences. In the primary smelter, aluminium is produced by dissolving alumina in a molten bath of cryolite, being a chemical compound containing sodium, aluminium and fluorine. An electric current is then passed through the solution to separate the aluminium from the oxide. This process requires considerable electrical energy to produce aluminium on a commercial scale, as 14 kWh is needed for every kilogram of metal. The melting point of pure aluminium is 659◦ C (1218◦ F). To prepare aluminium for the manufacture of cold rolled sheet for containers and ends, ingots of new aluminium from the primary smelting process, together with scrap aluminium, are added to a furnace operating at about 700◦ C (1292◦ F). Fluxes are added to aid the removal of impurities which

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159

are skimmed off the top of the liquid metal. Alloying elements such as magnesium and manganese are also added to give the correct chemical composition. The liquid is then moved to a holding vessel. Before casting into ingots, the liquid aluminium is degassed by the addition of chemicals and then filtered through porous ceramic blocks to remove any remaining solid impurities. This ensures that all the metal in the ingot is very clean. An ingot normally weighs approximately 13 tonnes. Aluminium may also be cast into a continuous slab, which is then cut into individual slabs for rolling. As the casting processes can produce rough surfaces on the outside of the slabs, which may also be contaminated with impurities, both faces of every slab are scalped to produce a smooth, clean, finish. To achieve this, approximately 12 mm (1/2 inch) is machined off each of the two faces. The edges are not touched at this stage. After preheating to 480◦ C (896◦ F), the slab is hot rolled down to a thickness of 2.5 mm (0.1 inch) and width of 1.55–2.0 m (61–79 inches). The hot coil is now allowed to cool down in air, during which time it becomes fully soft. This process of annealing in air may take two to three days. The fully soft metal is cold rolled down to the finished thickness without any further heat treatment. The mechanical work done during the cold rolling process produces the correct amount of hardness in the material.

Recycling of packaging metal Recycling leading to re-melting of packaging metals has always been a necessary step in the economical production of metal packaging by all production methods. Historically most of the scrap materials returned for reprocessing originated as process scrap from can and end making. In recent years improvements to household waste collection systems have permitted ever-greater quantities of metal packaging waste to be made available for remelting. Both aluminium- and steel-based packaging materials are readily remelted by the metal manufacturers. Waste materials arising during the can-making processes are returned for recycling through third party merchants. Post consumer metal packaging waste is collected by local authorities and after automatic separation from other waste materials is ultimately returned to the metal manufacturers for remelting. Aluminium- and steel-based packaging materials suffer no loss of quality during the remelting process and so may be remelted and reused an unlimited number of times for the production of first quality packaging material. It is well known that certain modern steel-making processes require metal scrap to be added for control of melt temperature amongst other things. While it is not necessary to remove the tin coating prior to remelting of tinplate as part of modern steel making processes it is clearly a desirable step to incorporate where technically and commercially possible. Specialist tinplate recycling processes exist which permit the tin to be separated from the steel substrate using reverse electroplating technology.

7.2.5

Metal can-making processes

Cans for food may be constructed as either three-piece or two-piece containers. Three-piece cans consist of a cylindrical body rolled from a piece of flat metal (blank) with a longitudinal seam (usually formed by welding) together with two can ends, which are seamed onto each end of the body. The three-piece can-making process is very flexible as it is possible to produce almost any practical combination of height and diameter. This process is particularly suitable for

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making cans of mixed specifications as it is relatively simple to change the equipment to make cans of different dimension. Three-piece cans have three metal-to-metal seams. Two-piece cans are made from a disc of metal which is reformed into a cylinder with an integral end to become a seamless container. To this is seamed a loose end to finally close the can. Twopiece cans have therefore only one metal-to-metal seam. Drawing is the operation of reforming sheet metal without changing its thickness. Redrawing is the operation of reforming a two-piece drawn can into one of smaller diameter, and therefore greater height, also without changing its thickness. This is called a drawn and redrawn can (DRD). For the economical use of materials, the height of a DRD can is usually no greater than its diameter. Ironing is the operation of thinning the wall of a two-piece DRD can by passing it through hardened circular dies to increase its height. The DWI process is very economical for making cans where the height is greater than the diameter and is particularly suited to making large numbers of cans of the same basic specification. The DWI can making system is mainly used for tall drinks and processed food cans. Because of the relatively small numbers of straight wall tall tinplate containers used for packaging heat-sterilised fish products this process is not normally used by this industry. For this reason only an overview of the DWI process is described below. Although the statement above about the economic height restriction for DRD cans is generally followed, one exception is that of the 73 mm × 110 mm tapered wall salmon can featured as example 7 in Figure 7.2. As already described, there are other overriding economic considerations relating to extreme distances of empty can delivery that take precedence in this case. The investment in tooling generally makes two-piece can making less flexible than three-piece in terms of making different can specifications on the same production line. Cans with parallel wall bodies are normally packed in multiple layers, one can high, with cardboard interleaving pads, onto pallets as this is the quickest way of automatically packing these products. As tapered wall cans are by definition nested one inside the other, these are packed into boxes containing stacks of nested bodies.

Three-piece welded cans (Tinplate only) Three-piece welded food cans may only be constructed from steel (tinplate), as aluminium is not suitable for welding by this particular process. ECCS (Tin free steel) can only be welded with difficulty unless special versions of ECCS are used. The body is formed from a rectangular blank with precise dimensions to suit the height, diameter and amount of overlap along the seam. Master sheet sizes are computed to suit the acceptable dimensions of coating, printing and curing (drying) ovens and to contain the maximum number of blanks per sheet. This latter consideration is very important in minimising wastage during subsequent cutting operations and maximising throughput efficiency. The width of the master sheet effectively defines the width of the coil purchased from the steel maker. The coils of tinplate, after delivery from the steel maker, are cut into master sheets approximately one meter by one meter. The cut sheets are then coated, and printed if necessary, to protect and decorate the surfaces. Areas where the weld will be made on the can body are left without coating or print to ensure that the weld is always sound. The coatings and inks are normally dried by passing the sheets through a thermally heated oven where the temperature is in the range 150–205◦ C. Alternatively, for some non-food contact uses, ultraviolet (UV)-sensitive materials may be applied. These are cured instantaneously by passing the wet coating/ink under a UV lamp. The sheets are next slit into small individual blanks, one for each can body, each blank being rolled into a cylinder with the two longitudinal edges overlapping by approximately 0.4 mm. In a welding bodymaker, the two edges are welded by squeezing them together whilst passing an alternating electric current across the two thicknesses of metal (see Figure 7.3). Because of the

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161

Cylinder rolling

Flat blank

Cylinder edges welded by squeezing together whilst alternating electric current passed through. This heats up metal for sound joint to be made.

Finished weld Thickness is 1.4 of original thickness of metal

+ Spot welding

Fig. 7.3

Side seam welding process. Reproduced with permission from Pira International.

electrical resistance of the metal, the passage of current heats up and softens it sufficiently for a sound joint to be made. If the can is internally coated with lacquer it is generally necessary to apply a repair side stripe coat to the inside of the weld to ensure coating continuity over the whole inside surface of the can. The material of this coating may be powder or liquid coating applied as a spray or rolled on. After coating the side stripe is cured by passing the can seam area under a long hot air nozzle (for details of coating systems, see Section 7.2.8). When making three-piece welded cans where the height is less than the diameter, the bodies tend to be unstable when travelling with the axis horizontal (i.e. can on its side). As welded can bodymakers form the cans in this orientation, a system of parting is employed. With this, the body blank dimension is made to accommodate the height of, say, two, three or possibly four short can bodies, depending on the limits of the machine itself. During the process of rolling the blank into a cylinder the blank is partially scored through at the point where each short can body will ultimately be cut. After the master blank has been welded, as one long can, side striped and cured, the multiple can body is passed into a parting machine which cuts through the scores in the plate and separates the short cans into individual units ready for the next operation. From this point in the process all cans travel with the axis vertical. The can body now passes through a flanging machine where the top and bottom of the can body are flanged outwards to accept the can ends. One end is then mechanically seamed on to the bottom of the can body. This process is described elsewhere in this book. Where easy-open ends are fitted to three-piece cans, it is a common practice for this end to be fitted at this point, leaving the plain end (non-easy-open) to be fitted after filling. This practice allows the seamed easy-open end to pass through the finished can testing process. At this stage, most tall food cans (height-to-diameter ratio more than 1.0, diameter 73 mm or greater) pass through a beading machine where the body wall has circumferential beads formed into it. The beads provide additional hoop strength to prevent implosion of the can during subsequent heat process cycles. All cans finally pass through an air pressure tester, which automatically rejects any cans with pinholes or fractures.

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The three-piece side seam welding process cannot produce taper wall cans. However for non-food applications it is possible to reshape the welded cylinder into a tapered wall container.

Two-piece single and multiple drawn (DRD) cans (steel or aluminium) Two-piece DRD cans may be made from steel (tinplate/ECCS) or aluminium. It is most economical in terms of minimal metal wastage and production speed for the metal to be fed from the coil directly into the first press operation. However this is appropriate only if the metal for the can is to be unprinted. While it is not practical to print metal in coil form it can be supplied pre-lacquered or with a plastic coating. If the can is to be printed before forming, the uncoated metal coil will need to be cut into master sheets first and printed/coated in the same way as is done for three-piece cans. The process of reforming flat metal into three-dimensional shapes usually requires some form of lubrication over the surface of the metal to ease its passage through the tooling and to prevent scratching. This may be supplied as a wax coating applied at the start of the process or more commonly by utilising the natural surface slip properties of the sheet coating materials. At the start of the can forming process metal in sheets or directly from coil is fed into a reciprocating press which may have single or multiple lane tools. For a single lane tool, where one press stroke makes one can, the width of the sheet/coil will equal the diameter/width of the flat blank (disc/rectangle) from which the can is to be formed plus a metal trim allowance of, say, 3–4 mm. For a multiple lane tool, where one press stroke makes multiple cans, the width of the sheet/coil will equal the width across all the blanks on the sheet plus a trim allowance. To minimise metal wastage, blanks will be laid out, where possible, in a close fitting pattern. For example, if the blanks are circular, the centres of three adjacent blanks will form an equilateral triangle with the gap between blanks being, say, 2 mm. Again, to minimise metal wastage, where sheets are being used and the width available is significantly greater than the width across the total number of blanks on the sheet (single or multiple) it is common to use a stagger-feed press. In this case, the sheet is held in grippers and moved sequentially in two dimensions first across and then through the press tool, line by line, to allow the tool(s) to punch out every blank on the sheet. At each tool station the press cycle cuts a blank (disc/rectangle) from the metal and whilst in the same station draws this into a shallow can (cup). During the drawing process the metal is reformed from flat metal into a three-dimensional can without changing the metal thickness at any point. This process is described in Figure 7.4. Also shown in the figure is the crossed–hatched circular pressure

Surface area remains constant and metal thickness does not change as metal is drawn from flat disc to shaped cup Fig. 7.4

Drawing a can from flat sheet metal.

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Disc cut from coil or sheet

Drawn into shallow can

163

Flange formed in top wall

Single draw shallow can

Disc cut from coil or sheet

Drawn into shallow cup

Redrawn into cup with smaller diameter

Redrawn into can with final diameter

Multiple draw tall can Fig. 7.5

Can forming by single/multiple draw.

pad which is used to control the rate at which the metal moves into the die orifice. This control is needed to prevent the metal from wrinkling as it is drawn into the cup shape. After this single draw, the can may be already at its finished dimension. However, by passing this cup through a similar process with different tooling, it may be redrawn into a can of smaller diameter and greater height to make a DRD can. This process may be repeated once more to form a can that has the maximum height achievable. At each of these steps, the can base and wall thickness remain effectively unchanged from that of the original flat metal. These processes are shown in Figure 7.5. It is usual for a flange to be left on the can body throughout the single or multiple drawing operations. After the final draw it is then necessary to trim the flat flange to provide the precise dimensions for the mechanical seam made after the can is filled and the end applied. As an alternative, the can body wall may be left straight and trimmed as a cylinder with a separate flanging operation done as the final step. Single and multiple draw cans may have either straight or tapered walls. Depending on the properties of the metals being used and the types of coatings applied, an additional drawing operation may be required to complete the forming of a tapered wall can. Control of metal flow in the drawing dies is more critical when tapered wall cans are being made particularly where the formation of wrinkles at the top of the sidewalls is undesirable. For all two-piece cans pinhole and crack detection on finished cans is carried out in a light-testing machine. This measures the amount of light passing across the can wall using high levels of external illumination. Where excessive light units are detected in the inside of the can it is automatically rejected at exit from the tester. The single drawing process is also used to make aluminium or steel tapered shallow trays for eventual heat sealing with coated metal foil. The container bodies are constructed from metal laminated with organic film.

Two-piece DWI cans (tinplate only for processed food cans) The draw and wall ironed can making process is effectively an extension of the draw-redraw process described above allowing tall cans to be made from the same starting point as the DRD cans. The

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Fish Canning Handbook

Disc cut from coil

Drawn into shallow cup

Redrawn into cup with smaller diameter

Wall thinned by ironing

Draw and wall iron tall can Fig. 7.6

Can forming by draw and wall ironing.

one exception to this is that DWI cans are constructed from uncoated tinplate because the wall ironing (thinning) operation would severely damage any coatings pre-applied to the metal surface. DWI cans for processed food are made only from tinplate as thin wall aluminium cans do not have sufficient strength to withstand the heat process cycles and thick walled cans would be prohibitively expensive. For this process uncoated tinplate is fed from the coil directly to the cup-making process with multiple cups being made using the full width of the coil at each stroke of the press. The cups are then fed to a number of parallel body-making machines which first redraw the cups into short cans with the diameter of the final can and then convert the short cans into tall cans by thinning the walls. Figure 7.6 demonstrates this process in outline. The tops of the cans are then trimmed to the correct height prior to being washed. Following this, external coating is applied by passing the upturned cans under a series of waterfalls of clear lacquer, which protects the surface against corrosion. The lacquer is dried by passing the cans through a heated oven. Following this, the can body now passes through a flanging machine where the top of the can is flanged outwards to accept the can end, which will be fitted after the can is filled with product. The flanged can is next passed through a beading machine which forms circumferential beads in the can wall, to give added strength to the can. After all the mechanical forming operations have been completed, every can is tested by passing through a light tester which automatically rejects any cans with pinholes or fractures. The inside of each can is then coated with lacquer using an airless spray system. The special lacquer is applied to protect the can itself from corrosion and its contents from any possibility of interaction with the metal. This lacquer is finally dried in a thermal oven at a temperature of about 210◦ C.

7.2.6

Metal end-making processes

Can ends for mechanical double seaming are constructed from aluminium, tinplate or ECCS (Tin free steel). Aluminium and ECCS are always coated on both sides with organic lacquer or film laminate whilst the metal is still in coil or flat sheet form. For tinplate these coatings are optional depending upon the product being packed in the container and the specified external environmental conditions. The base of a three-piece can will always be a plain end (non-easy-open). For food cans the top may be plain (requiring an opening tool), full aperture easy-open or peelable membrane. Finished ends are packed in paper tubes on pallets for internal use by the can maker or for onward shipment to the can filler.

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All plain and full aperture easy-open ends for processed food cans have one or more circular beads in the centre panel area to provide flexibility. These allow the panel to move outwards as internal pressure is generated in the can during the heating cycle of the process and so reduce the ultimate pressure achieved in the can. During the subsequent cooling process, this flexibility permits the centre panel to return to its original position. For peelable membrane ends the particular design and material specification will determine whether the peelable membrane is capable of withstanding the internal pressure generated in the container or whether special overpressure retorts need to be employed to limit this pressure.

Plain food can ends and shells for full aperture easy-open ends The initial processes for making plain and easy-open ends for food cans are the same. The body of an end which will be ultimately converted into an easy-open end is referred to as a shell. Plain ends/shells may be stamped directly from wide coils of metal or from sheets/strips cut from coils to produce very shallow drawn cups. Metal in coils may be provided with a clear coating on both sides if the ends are not also to be printed. Alternatively coil may be cut into sheets and coated/printed as necessary to suit the required specification. These processes are the same as those described for DRD cans in section ‘Two-piece single and multiple drawn (DRD) cans (steel or aluminium)’. Whether from coil/sheet or strip, the metal is fed through a press which produces multiple stampings for every stroke. Again, these processes are the same as those described for DRD cans above. Figure 7.7 shows the steps used to form the plain end. After removal from the forming tool, the edges of the ends/shells are then curled over slightly in a separate operation to aid in the final operation of mechanical seaming the end onto the flange of the can. After curling, the ends/shells are passed through a lining machine which applies a bead of liquid lining compound via a nozzle around the inside of the curl. The lining compound, which has the texture of liquid rubber, is dried

Prepared metal sheet or strip Round blank cut out in press tool

Blank formed into end in press tool ‘Start’ curl straight End transferred to curling tool ‘Finished’ curl rounded

Seaming panel

Centre panel

Plain food end Fig. 7.7

Plain end making.

Curled end to compound lining Countersink

End-forming process

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Fish Canning Handbook Plain end shell Full panel opening ends for food

Rivet pin formed from centre panel

Tab fitted over rivet pin Line of score around opening panel Typical score

Tab riveting operation

Score residual thickness Internal surface of end Fig. 7.8

End conversion to easy-open.

either in air or under heat depending on the nature of the solvents contained in the material. It is normally necessary for the lining compound to dry for 24 hours to develop sufficient mechanical strength before the end is seamed onto a can body.

Conversion of end shells into easy-open ends The conversion of an end shell into an easy-open end comprises the two operations of scoring the perimeter of the opening panel for ease of opening and attaching a metal tab with which to tear open the panel. These operations are described in Figure 7.8. Scoring is the operation of partially cutting through the body of the end to ensure that the tear takes places in the correct place and that the forces necessary to open and remove the panel are within acceptable limits. Finished ends are tested for ‘Pop and Pull’ forces to ensure these limits are being met. The score is cut into the centre panel from what will be the outside surface of the end and forms a ‘V’ notch. The amount of end metal thickness remaining at the bottom of the score is called the score residual and will usually be less than 50% of the original metal thickness. As aluminium is softer and easier to tear than steel, the allowable score residual percentage is greater than that for steel-based ends. Steel-based easy-open ends are therefore more difficult to make because the accuracy of the scoring process must be greater to ensure the correct range of score residual thickness remains. Too great a figure may make the end difficult to open, too small a figure may result in end failure under extreme physical conditions. Although the outside surfaces of the end may already have been coated at some point, a further operation to ‘repair’ the coating in the score notch area may be undertaken. The pull-tab is made from a narrow strip of pre-coated aluminium or steel, which is supplied in narrow coil form – wide enough to fit, say, up to three tabs side by side. To avoid bimetallic corrosion the tab is made from the same type of metal as the end shell. The strip is passed through a multistage press tool which first pierces and then cuts out the outline of the tab(s) before completing the formation of the folded tab(s). During the piercing step a small number of ‘bridges’ are left

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1. Standard plain end 2. Centre panel cut out and removed 3. Internal edge prepared 4. Pre-cut aluminium foil lid heat sealed in place

Detail of heat seal and edge preparation

Tear tab

Heat seal area

Cut metal edge protected by heat seal

Fig. 7.9

Peelable membrane end making. Reproduced with permission from Pira International.

uncut to allow the tab to remain connected to the original strip throughout all the forming steps. The tabs are now ready for attachment to the end shells. After the scoring operation, a hollow upstanding rivet (closed-end tube) is formed in the centre panel of the shell. The strip containing the formed tab is fed over the upstanding rivet on the shell and the rivet is deformed to make a joint between the two components. At the same time, the remaining connecting bridges to the tab metal strip are broken. Easy-open ends are normally tested for leakage after manufacture using a gas sensing system.

Peelable membrane ends Peelable membrane ends have been developed as an alternative to easy-open ends. Although they are likely to be more expensive than easy-open ends, they may be considered by some to be more user-friendly. This end is made by taking a conventional food can end shell, cutting out a disc from the centre panel, making the remaining cut-edge-safe by folding and finally heat sealing an aluminium foil lid over the aperture. This process of manufacture, shown in Figure 7.9, is carried out by the can maker in ‘clean’ conditions, therefore the chance of contaminants being present across the heat seal face are minimal. The complete peelable membrane end is mechanically seamed onto the flange of the can body after filling in the same way as a plain food can end. The fact that the final closure of the filled can is made by conventional mechanical seaming for what is effectively a heat sealed closure is a major benefit of this particular type of end. Any contamination across the can flange, from strands of food, bone etc., left by the filling process, is completely destroyed by the mechanical seaming process. Similar types of contamination across a heat sealed surface could lead to failure of the seal.

7.2.7

Mechanical properties of metal cans and ends

One of the main positive attributes of metal packaging is the fact that the metals commonly used for packaging have high strength-to-weight ratios. Although the figure for aluminium is less than

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that for the steel-based materials it is still possible to construct metal packages with wall thickness in the range of 0.26 mm down to 0.10 mm that will withstand full heat processing systems with temperatures up to 132◦ C. Resistance to vertical axial load during can seaming and handling/warehousing of filled cans coupled with resistance to implosion (panelling strength) of the body sidewalls during heat processing are determined by the design of the container and the tensile strength of the metal in the finished container. These issues are more critical with tall cans than with shallow drawn cans. The process of forming three-piece tinplate can bodies does not change the thickness or strength of the metal, so when this material is purchased the tensile strength must be specified to suit the duty of the filled container. Tinplate used for these families of containers is therefore specified as high tensile, so as to allow materials of the thinnest possible gauge to be utilised. At the other end of the spectrum, DWI cans require lower tensile, high ductile, metal to be used for the initial body forming operations because it is easier to form. However the forming process itself, which includes wall thinning, imparts cold working to the metal, like cold rolling, which in turn increases the tensile strength. The walls of the finished can then have high tensile properties allowing very thin walls to be used. Standard specifications available from suppliers of tin mill and aluminium packaging metals cover a very wide variety of tempers (tensile strength), ductility and surface finishes. The side seam weld on a three-piece tinplate can, created by squeezing together two layers of hot metal (described in section ‘Three-piece welded cans (Tinplate only)’) makes a joint that is in fact stronger than the parent metal on either side of it. Resistance to wall denting is another function of wall thickness and tensile strength. Greater tensile strength makes the metal more ‘springy’ and therefore more resistant to permanent deformation. This again is an issue more often encountered with tall than shallow drawn cans. The performance of can ends, including integral can bases on two-piece cans, is also closely linked to the tensile strength and thickness of the metal used. However, the detailed design of the centre panel of the base/end of a food can is also extremely important. The prime duties of the can end are: 1. To withstand internal pressure without buckling outwards and for the flexible centre panel area to move outwards to relieve internal pressure both during the heat process cycle. 2. For the centre panel to return to its original position as the can cools down following the heat process cycle and a negative pressure is induced in the can. 3. To provide a link via the seaming panel area to the flange of the can so that a permanent mechanical hermetic seal is made. Easy-open ends have additional mechanical requirements over and above those described above. The ability to create a rivet out of the centre panel metal to which the tab is ultimately connected requires metal with good ductility to avoid cracking or breaking open. To ensure good repeatability of the loads required to crack open and then peel along the score line (pop and pull loads) the metal itself must have extremely consistent mechanical properties. Heat seal lidding system materials employed in peelable membrane ends must have sufficient strength to withstand the internal pressures generated in the containers during the heat process cycle. Not all such materials are suitable for use in standard retorts without overpressure control.

7.2.8 Coating and printing of metal for packaging Coating of metal for packaging With a few exceptions, most fish products contain sulphides which will react with some metal surfaces to produce compounds that will then stain the product itself. For this reason, all internal

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surfaces of metal packages for heat-processed fish products have an organic coating applied to provide an inert barrier between product and metal. However this is not always sufficient in itself to eliminate staining so these coatings usually contain a masking pigment or a sulphur-absorbing compound. Organic coatings may be in the form of liquid-applied coatings, polymer film laminates or polymer films extruded directly into the metal surface. Liquid applied coatings comprise resins, which part forms the final hardened surface, let down in solvents (organic or organic with water) to aid the application and curing (drying) processes. For all liquid coatings which come into direct or indirect contact with the food product, it is currently necessary to use materials which are thermally cured. This is achieved by passing the metal with wet coating applied through a tunnel oven which has hot air circulating at temperatures in the range 160–210◦ C depending on the particular coating specification being used. The air is usually indirectly heated by gas. As the metal enters the tunnel the liquids are first evaporated off then the resin is chemically cross-linked to create a hard but flexible protective surface. Care needs to be taken that there is no contact with wet lacquer surfaces prior to curing as such contact could lead to pinholing through the lacquer and the potential for a failed can. This is facilitated by supporting the wet sheets in the near vertical position with wire frames (wickets). The dry sides of the sheets lean against the wire frame while they travel through the heated oven. UV curing coatings (and inks) are based on solvent free liquid resins. These resins, combined with photo-initiators, can be cured by exposure to UV light emitting lamps and because heat is not required for this process, the curing time can be as little as one second. The immediately perceived benefit of this system over conventional thermally cured coatings is one of increased curing speed, reduced energy consumption and significant space saving. The other potential major benefit is the elimination of any solvent emissions to the air, although this process does produce ozone gas, which must be safely extracted from the local workplace. There are however some limitations to the use of UV curing materials. At present they are not generally authorised for use in direct contact with foodstuffs and the extremely fast curing time does not allow chemical cross-linking to develop sufficiently to give coatings as flexible as those produced by thermal curing. The presence and type of pigments in the coating will have an effect on the rate of cure, the denser the pigment the longer the cure time. To overcome the problem of indirect contact with foodstuffs, it is sometimes possible to put down a coat of UV cured coating followed by a coating of thermally cured material as the top layer. For three-piece cans, two-piece drawn containers and can ends, the metal is coated (and printed) while it is flat, in coil or sheet form, prior to the can or end forming operations. The coating of metal coil or sheet is always done by roller coating, details of which are shown in Figure 7.10. As three-piece can bodies are formed from individual blanks any coating (or printing) necessary is done while the metal is in master sheets prior to slitting. For three-piece welded cans with an internal coating, it is also necessary to apply a coating to the inside of the weld area after the body has been made so that the whole of the internal body surface is coated. This side stripe operation may be done by roller coating or powder/liquid spray. Curing of this stripe is achieved by heating the external surface of the can weld area using hot air blown through a nozzle to concentrate the flow. Powder coating, being 100% resin, does not contain any organic solvents and can be applied in greater weights per unit of area than the liquid materials. The applied powder side stripe coat is however more expensive than the liquid or spray coatings. Two-piece drawn containers and can ends may have coatings applied while the metal is in either coil or master sheet form. Because of the large scale of plant required, coil coating of tin mill products or aluminium is usually undertaken by the metal manufacturer and for this reason is restricted to products where only very large quantities of products having the same specification of coating are needed. However, where this restriction is no problem, the benefits of using coil-coated

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Fish Canning Handbook Transfer roller Fountain roller

Application roller

Metal sheet

Pressure roller Scraper Pump

Coating reservoir Fig. 7.10

Coating of metal sheets. Reproduced with permission from Pira International.

metal are considerable from both a reduction in metal wastage and an increase in output from the initial cupping press operation. For two-piece cans and ends made from coated sheets the technology is identical to that used for three-piece cans (described above). During the process of cutting scores in easy-open ends the previously applied coating becomes ruptured. This may be post-repaired by using a spray or electrochemical methods using anodic protection to apply coating to these areas. For two-piece DWI containers all coating (and external decoration) is carried out after the can body has been formed. The internal surfaces of two-piece DWI cans are coated by airless spray. For food cans, where paper labels are normally applied, the outside surface is flood-coated with clear lacquer with the can in the upturned (base uppermost) position. After surplus coating has drained off, the residual material is cured by passing the upturned cans through a hot air oven. The most common resin base for internal coating of heat-processed fish cans and ends with liquid coatings, whether constructed from tin mill products or aluminium, is epoxy phenolic. Organosols and polyurethanes are also used in some parts of the world on drawn containers. Epoxy phenolicbased coatings are particularly versatile as they can be used for both three-piece, shallow drawn and DWI containers. Organosols, because of their extreme flexibility, are particularly appropriate for very deep drawn cans. For drawn cans epoxy phenolic may be used over a base coat of organosol. For easy-open end internal coatings, two coats of epoxy phenolic or double coat epoxy phenolic plus a single outer coat of organosol may be used depending upon the degree of chemical activity. In the introductory paragraph to this section, mention was made of the issues of sulphur staining of certain metals. This is particularly applicable to tin where, in combination with sulphur in the product, tin sulphide may be produced. In extreme conditions of steel-based can corrosion, where bare steel is evident, then iron sulphide may also be produced. Both these sulphides are black and are likely to cause staining of the packed product. Application of high-quality coatings with sufficient

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coating weight (in single or multiple coats as appropriate) will go some way towards alleviating these problems. However the properties of the product being packed will also have a significant influence on the result. Two different methods are used in the world to overcome issues of sulphur staining. The first, employed in the United States, uses zinc oxide as an additive to the coating. This has the effect of absorbing sulphur from the product near to the can wall. The second, employed in Europe and Asia, uses an aluminium pigment additive to the coating which has the effect of masking the staining. Some can fillers also use aluminium pigment coatings on ECCS materials, when it is not strictly necessary, to give their cans the same internal appearance as those made from tinplate. Deep drawn cans, such as those for salmon packing in the United States, are sometimes made from coil-coated ECCS with epoxy phenolic coating plus aluminium pigment plus a meat release agent to help the meat come away from the can wall after opening. At the end of section on ‘Steel for packaging’, mention is made of plastic coatings and laminates for steel. In Europe the three main manufacturers of packaging steels also make plastic-coated steels for specific market areas. Corus Packaging Plus (the Netherlands) has developed Protact, which is an ECCS substrate with multiple layers of PET hot extruded directly onto the surface of the metal. For the salmon cans shown as examples 7 and 8 in Figure 7.2 (also shown in Table 7.1 under two-piece round (conical) 418 g and 213 g cans) special coating systems have been developed for the can bodies. These comprise three-layer PET coats on both internal and external surfaces. The internal layer also includes release properties. Other material coat combinations have also been developed for the rings of peelable end systems. These incorporate heat seal properties for the layer in contact with the aluminium lidding. These PET coatings can have pigments incorporated. Rasselstein (Germany) has a product Andrafol, which is a film lamination system for either tinplate or ECCS. The coating film can be PET (polyethylene-terephthalate), PP (polypropylene), PE (polyethylene) or lacquer and can be applied in various combinations. For food packaging these materials are used for can bodies and easy-open ends. Arcelor–Mittal (France) also provides film-coated steels for food cans and ends.

Printing of metal for side seam welding and can drawing processes Printing on metal for packaging fulfils two roles; it creates the image that the brand owner wishes to use to catch the eye of the consumer whilst providing all the information necessary to describe the contents and satisfy any legal requirements. Metal is a particularly good substrate on which to print because the hardness of the surface allows a very clear image to be formed. For metal containers formed from cut sheets, i.e. side seam welded or drawn bodies, the process of laying down colour onto the sheet surface is the same. Likewise the process of printing onto steel or rigid aluminium sheets is the same. For DWI containers printing is applied to the tubular body after the initial metal forming has been completed. As DWI cans are not currently used for heat-processed fish products no further description of this process is given. Drawn containers, whether straight or tapered wall and which are generally formed from circular or rectangular blanks, require the image on the blank to be pre-distorted to take account of the movement of the metal as the side wall is formed. The further away the image is from the base of the can the greater will be the amount of pre-distortion needed. It follows that for shallow drawn cans the amount of distortion from bottom to top of the side wall will be relatively small. However, on a deep drawn can the distortion will be considerable at the top of the wall and care must be taken to ensure that sensitive parts of the label design and text remain legible at this point. Calculation of the amount of pre-distortion necessary used to be a manual task, fortunately this work is now able

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to be done by computer. The issues related to the design and generation of images for distortion printing can be eliminated by making a container from plain undecorated metal and then packing the can in an individual printed carton. This method is often used for Club and Dingley cans containing sardines etc. Generation of colours by multi-colour process sets is the same when printing on metal as for any other medium. The four-colour process set is the most common way of producing the range of colours present in a photograph. The specific standard colours used are cyan, magenta, yellow and black. Combinations of these will simulate 50% of the Pantone range of colours. In 1994, Pantone Inc. introduced the six-colour Hexachrome system, which simulates more than 90% of the range. This system, which adds green and orange to the original four colours, has recently been introduced to the metal packaging industry. The benefits of this process are the ability to produce sharper images and a greater range of colours. In some instances it will also be possible to produce a ‘house’ colour from the six-part set instead of having to introduce a special colour pass. Printing inks are pigments dispersed in a liquid or semi-solid carrier, where the carrier is designed to suit the particular method of printing. The most common printing methods are lithographic, flexographic, gravure, silk screen etc. The basic process used for printing rigid flat metal sheets is offset lithography while that used for printing coils of flexible aluminium is either flexo or gravure. The latter processes are used, e.g. for printing aluminium foil laminated to polymers from which individual blanks are cut for heat sealing onto metal for manufacture of peelable membrane ends. In offset lithography the word offset refers to the process of first transferring the print image from the printing plate to a rubber blanket and then transferring this image onto the metal sheet. In this process, therefore, the printing plate does not come into direct contact with the metal sheet being printed. In traditional lithography, the printing plate image is flat and made so that the image area, whilst being receptive to ink, also repels water. By contrast, the non-image areas are receptive to water. For this system to work, the ink must not be miscible with water. When the process is running, a damping roller system applies water to the surface of the print plate. The water is repelled by the image area of the plate but covers the non-image areas. A uniform layer of ink is fed to the printing plate but it adheres only to the image areas, as these are not covered by water. This process is referred to as a wet offset system. Whilst this is the system which has been used successfully for many years, there can be problems in maintaining satisfactory control of the damping system. A typical offset litho sheet printing press layout is shown in Figure 7.11. In recent years, dry (Toray Waterless system) plates have been introduced which completely eliminate the need for the damping system. For these plates to work satisfactorily, the surface temperature of the printing plate and the ink must be very closely controlled, requiring the installation of water-cooled printing plate cylinders. The use of dry plates, whilst requiring special inks, simplifies the operation of the process and provides a more consistent print quality. This in turn reduces spoilage and set-up times. Curing of printed surfaces may be by application of heat or by chemical curing using light such as UV depending on the particular type of ink used. The methods of curing are identical to those used for organics coatings described in the previous section.

7.2.9 Selection of the can-making route Each of the three basic can-forming processes described above has advantages over the other two. To help in understanding which can-making route is the most appropriate for a

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Ink feed and distribution rollers

Ink drum

Printing plate cylinder

Intermediate distribution rollers Damping system

Blanket cylinder

Metal sheet

Impression cylinder

Fig. 7.11

Printing of metal sheets by offset wet lithography. Reproduced with permission from Pira International.

particular set of circumstances it is necessary to look at the abilities of each process in respect to:

r r r r r

Flexibility to make different cans of different diameter and height-to-diameter ratio (also relates to volume of market for a single can size); Manufacturing cost (includes material usage efficiency); The most practical and economic height-to-diameter range available (may be limited by the physical capability of the process); The ability to create cans with tapered (conical) walls. This is particular important for certain cans for fish, as opposed to processed food cans in general; and The ability to form cans with different cross-sectional shapes.

A comparison between some of the most critical attributes of the three can-making processes is shown below: Three-piece welded side seam r Very flexible, within limits, height/diameter change is easy to carry out and all height-todiameter ratios can be accommodated r Higher cost – medium to low quantity r Tapered cans – no (can only make taper post welding and that only for non-food cans) r Form cross sections other than round – only by reforming cylinder after welding Two-piece seamless DRD r Moderately flexible. Ideally max height ≤ diameter, any size change needs new tooling r Medium cost – medium quantity r Tapered cans – yes r Form cross sections other than round – yes

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Two-piece seamless DWI r Current lines relatively inflexible. Height > diameter, any size change needs much new tooling and time to convert r Lower cost – large quantity r Tapered cans – no r Form cross sections other than round – no The following additional comments about the processes should also be noted. While the DRD process is able to produce tapered wall containers, it is not possible to add wall strengthening beads to tapered walls. For tall tapered DRD cans, as shown in Figure 7.2, example 7, the additional side wall strength needed to withstand the heat process system can be provided only by increasing the thickness of the side wall metal. In general the DWI process is the most economic in terms of metal use provided the cans are tall. However, to achieve these economies, the lines need to run continuously and produce many millions of cans to the same specification. Annual output capability is about 600 million cans. The DWI process is not currently used for fish cans as quantities are not great enough for economic production but the future introduction of mini DWI lines may overcome this limitation. The three-piece side seam welding process is by comparison very flexible in terms of size changes. Metal economy is less good than DWI because of the need to make separate ends for the base of the can and it is more difficult to make very thin wall cans. Annual outputs are in the range of 200–300 million. The draw–redraw process falls in between the other two processes on most counts. However, the ability to make tapered and non-round shapes is a major benefit for the special requirements of the heat-sterilised fish can market.

7.2.10

Mechanical double seaming of ends onto can bodies

The standards employed during the process of mechanical double seaming ends onto can bodies are extremely important in ensuring the ongoing safety of the product packed into the container as, after heat processing and cooling is completed, the internal pressure in the can is negative. As a consequence of this, any weakness in the double seam could lead to micro leaks and the introduction of non-sterile air into the container. It is critical therefore that can makers and can fillers have an in-depth understanding of the process and the controls necessary to ensure that completed seams are of the necessary quality. Detailed industry standards, based on many years of operating experience, exist in many countries/continents to assist operators in meeting these goals. These standards are also designed to ensure that practical interchangeability is achieved when end and can components are purchased from different sources. After being established at the start of the twentieth century, the basic principles of the process of mechanically double seaming ends onto can bodies remains essentially unchanged to this day. However, the demands of lightweight containers and high-speed filling lines now put extreme demands on seaming systems and operational controls to ensure trouble-free performance. The basic system of double seaming described below is the same for food, drink and aerosol cans and is applied to both round and non-round ends. As the seaming tools have to follow the profile of the can/end cross section, it follows that the attainable seaming speeds are very dependent on this profile. In practice this means that round cans of, say, 73 mm diameter may be seamed at speeds up to 800 cpm whereas non-round cans of similar end circumference may only be seamed at speeds of up 250 cpm. These are only indicative figures as precise numbers must depend on the specific package materials, filling systems and seaming equipment being used.

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End seaming panel

End countersink

Can body wall

End placed over body flange

Fig. 7.12

After first roller operation

After second roller operation

Stages in the formation of a double seam.

Figure 7.12 demonstrates the sequence of the loose end being offered up to the can flange and the two seam roller operations to create the finished seam. The inside diameter of the end curl is just sufficient for it to drop cleanly over the flange of the can. If the end were not curled the two components would not lock together as the seam was made. During the seaming process, which is in two stages, the end is mounted on a round (or non-round) chuck which fits the external surface of the countersink wall and supports this wall during the seaming process. The first-stage external roll rotates the seaming panel of the end with the can flange to close them up as shown. The second-stage external roll tightens up the seam to give the correct final external dimensions and produces the required hermetic seal. Both first- and second-stage operations are carried out in the one seaming machine. The cross-sectional view of a finished double seam is shown in Figure 7.13. The box in the figure lists the main measured parameters of the seam. It will be seen that some of these dimensions can be taken from the outside of the finished seam while others can be measured only from a cross-sectional view. In practice this view may be obtained either by cutting through the seam or using X-ray technology available today from specialist instrument makers. The latter technology obviates the need for any cutting and saves time when multiple views are required from different positions around the seam. It also allows the seam to be viewed when under normal operating conditions. Some parameters cannot be measured directly from the seam cross section but require simple mathematical calculation to deduce the result. B G

A - Seam length B - Seam thickness C - Countersink depth D - Body hook E - End hook F - Overlap G - Seam gap

Fig. 7.13

D

The main measured parameters in a double seam.

F

E

A C

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The seam standards referred to at the start of this section specify the seam parameter dimensions and tolerances and highlight those which are considered to be critical for acceptable can seams. For specific products, detailed specifications may have to be agreed between can maker and can filler. In this case the can maker should define the critical parameters, operating parameters and recommended weekly checks. When setting up a seam, it is essential to have a good first operation seam as without this it is virtually impossible to achieve a good-quality (second operation) finished seam. The main purpose of the dimensional parameters is to ensure that the hooks created by the can body flange and the end curl have sufficient overlap and that all the layers of metal in the seam are compressed together sufficiently. It is also important to ensure the correct balance of dimensions within a double seam, for this the difference between the thickness of the end and the flange metal must not be too great. A typical list of critical parameters would contain the following, although it must be pointed out that this list may vary slightly in different areas of the world:

r r r r r r

Seam length (height) Seam thickness Overlap Free space Body hook butting Tightness rating (percent wrinkle)

The top three critical parameters in the list are measured directly from the seam cross section, being reference letters A, B and F, respectively, in Figure 7.13. Free space is the difference between the actual seam thickness B and the theoretical thickness calculated from (3 × measured end thickness) + (2 × nominal can flange thickness). Body hook butting is a measure of the balance between the body and end parts of the seam, while achieving an acceptable seam gap G and good overlap F. Seam tightness rating is the wrinkle-free length of the end hook. For satisfactory seam assessment it is normal to take a number of sections depending on the method of can construction. For round cans with welded side seam, the weld is taken as 12 o’clock and sections would be taken at the most vulnerable points of 2 o’clock and 10 o’clock. For round seamless drawn cans two points opposite to each other are usually selected. For non-round containers which are more difficult to seam it is necessary to take more sections. On a rectangular container these might typically be one on each long side and one at each of the corners. The physical performance of a can end in terms of its resistance to buckling due to excessive internal pressure is affected by end metal thickness and temper, depth of countersink, tightness of seam and strength of the top wall of the can. For this reason the top wall of thin wall cans, such as those made by the two-piece DWI process, is often made thicker than that of the can mid-wall to give additional support to the end through the mechanical seam. It is also important that the physical performance of the two ends of a can is similar, even if one of these is integral with the body as in a two-piece can. If the two ends do not have a balanced performance, it is possible that, in conditions of high internal pressure, the weaker end will take the entire expansion load and fail at an unacceptably low pressure. One of the reasons that the double seamed joint has performed so well over so many years is its ability to tolerate flange contamination by the filled product without impairing seal integrity. It appears that the mechanical forces imparted to the metal in the seam are more than sufficient to make a good seam in spite of the presence of foreign material on the face of the flange.

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7.3 PLASTIC CONTAINERS FOR HEAT-STERILISED FISH PRODUCTS Plastic containers for heat-sterilised fish products may be in the form of retortable pouches which are flexible, semi-rigid or rigid. These were first reported as being introduced in the United States, in 2002, for tuna products with the aim of improving the quality of the product over that of the steel can being used at the time. It was quoted by the CEO of Del Monte Foods that the pouch had no broth added and is a ready to use, high quality offering. The US Fisheries and Aquaculture Department in its document entitled ‘Manual on fish canning, Section 2. Packaging materials for canned fishery products’2 states: With the development of plastic and plastic and aluminium foil, flexible, semi rigid and rigid laminated packaging materials, has come a range of systems suitable for in-container sterilization of fishery products. Of these, the best known is the retortable pouch, which because of its flat profile and correspondingly high surface area to volume ratio (relative to that of cans) heats more rapidly than conventional cans. However despite certain of these advantages; (e.g. greater retention of heat labile nutrients and other quality benefits arising due to rapid heat transfer to the thermal centres of retort pouch packs; the favourable costs of transportation, and the ease of opening and heating contents) they have not replaced, to the extent that was anticipated, conventional packaging materials for heat sterilized fishery products. Whether considering retortable pouches which are flexible, semi-rigid or rigid, all offer the common attraction of providing a means to minimize the nutritional and sensory quality losses (which are often associated with traditional thermal processing in rigid containers), while simultaneously providing the opportunity to display visually appealing products. This is why developments with pouch packs are establishing a tradition of promoting a high quality image for fishery products. Some of these comments are borne out in the fact that pouch packs of tuna still only form a very small percentage of the total heat-sterilised fish products displayed on supermarket shelves. Certain of these packs are designed for microwaving the product in the pouch.

7.4

GLASS CONTAINERS FOR HEAT-STERILISED FISH PRODUCTS

The US Fisheries and Aquaculture Department in its document entitled ‘Manual on fish canning, Section 2. Packaging materials for canned fishery products’2 states: With the exception of some fish pastes, glass is rarely used for fishery products which are preserved by heat alone; however, it is frequently chosen to package semi-preserved items such as salted fish, pickled herrings and caviars. The principles of processing in glass are substantially the same as for cans, but there are certain modifications which are necessary because of the sealing mechanisms used, and the thermal properties of glass, which make it vulnerable to rapid changes in temperature of more than 50◦ C.

2

US Department of Fisheries and Aquaculture. Manual on Fish Canning.

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Two different closure systems are used for glass containers for heat-sterilised fish products. Fish paste jars are commonly closed by an aluminium press-twist closure. This embodies a plastic sealant flowed into the side wall of the cap during manufacture. After filling, the cap is pressed over the thread forms around the top of jar. During the sterilisation process the heat softens the sealant which then fully flows into base of the glass threads. The glass containers for most other fish products are closed by a steel lug cap, commonly used for fruit preserves, pickles etc. This cap had preformed lugs which screw into the start threads cast into the neck of the jar. One particular advantage of packing food products in glass is that the product can be viewed from the outside of the pack. A large diameter metal cap may have sufficient surface area to take all of the printed information needed to describe the product, in which case the whole of the glass surface is available for viewing the product. This method of display is often used for caviar.

FURTHER READING Coles, R., McDowell, D. and Kirwan, M.J. (2003) Food Packaging Technology. Blackwell Publishing Ltd., CRC Press, Oxford. Morgan, E. (1985) Tinplate and Modern Canmaking Technology. Pergamon Press, Oxford. Page, B. (2001) Metal Packaging: An Introduction. Pira International Ltd., Leatherhead, Surrey, UK. Pilley, K.P. (1994) Lacquers, Varnishes and Coatings for Food & Drink Cans and for the Metal Decorating Industry. ICI Packaging Coatings, Birmingham. Theobald, N. and Winder, B. (2006) Packaging Closures and Sealing Systems. Blackwell Publishing Ltd., CRC Press, Oxford.

8

Retorting machinery for the manufacture of heat-sterilised fish products

Claude Vincent

8.1 INTRODUCTION Canned fish products require to be sterilised by heat in order to secure lengthy preservation at room temperatures. The retorting or sterilising process was developed more than two centuries ago by the French engineer Nicolas Appert who discovered that a food product filled in a sealed container could be preserved at room temperature for a long time after exposure to a temperature in excess of 100◦ C. It is general knowledge today that sterilisation means the total destruction of all viable microorganisms. However, at the end of the eighteenth century, Appert, like anybody else, was unaware of the existence of microbes, germs and bacteria which limit the shelf life of most food products. Appert discovered the sterilising process, but was ignorant of the reason why products treated with heat were becoming stable and safe. Such understanding came considerably later with the discovery of microorganisms by the French biologist Louis Pasteur. Nowadays it is not unusual to use the word Appertisation instead of sterilisation. Both mean exactly the same thing. The equipment used for sterilisation of canned products is commonly called an autoclave, retort or steriliser. Since Appert’s time, the principle of autoclaves has not significantly changed. There is a chamber, in which containers are heated, which is able to withstand an internal pressure and hold the temperature in excess of 100◦ C. The heating medium used inside the chamber has always been either saturated steam or hot water, and this is still the case today.

8.1.1

r r

Reminders

Autoclave, retort and steriliser are the common words used to designate sterilising equipment for cans. Therefore the sterilisation process, retorting process or sometimes used Appertisation process refers to the same heat treatment. Canned food – canning industry.

The most common container used for the production of heat-sterilised foods by autoclave was in the past, and still is, the metal can. Although a number of other types of containers have been developed and used during the last 50 years, we continue to speak of ‘canned food’ and the ‘canning industry’ even if containers, such as glass bottles, plastic bottles, glass jars, flexible pouches, plastic or aluminium trays and so on, are used as the packing material for heat-sterilised products. Nowadays, the proportion of heat-sterilised products filled in a package other than a can is becoming larger and larger and, as a consequence, the retorting equipment has been adapted accordingly.

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8.2 RETORTING EQUIPMENT AVAILABLE The purpose of a retort is to heat a product filled in a sealed container and to maintain the suitable temperature until the sterility of the product is reached. The very primitive autoclave used by Appert was limited in application. Any type of retort available on the world market today is able to provide sterility of a canned product. However, depending upon the operation principle and grade of sophistication, some retorts are more appropriate than others for a specific application.

8.2.1

Types of retorts currently available

Sterilising equipment may be batch or continuous in operation. However, batch retorts are almost exclusively used by fish canners. Batch retorts can be classified into categories depending upon the heat exchange medium which surrounds the cans during the heat treatment. The possibilities are: 1. 2. 3. 4.

Saturated steam retorts; Full immersion retorts – the heat exchange medium is hot or superheated water; Steam/air retorts – the heat exchange medium is a mixture of steam and air; and Cascading water retorts – the heat exchange medium is superheated streaming water.

During sterilisation the retort is required to undergo a number of operations within the total cycle (see Figure 8.1). 140 Temperature of water inside autoclave

3.5

Temperature of product inside package

120

3

Temperature (°C)

100

2.5

Counter-pressure inside autoclave

80

2

60

1.5

40

1

20

0.5

0

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 Time (minutes)

Fig. 8.1

Description of a sterilisation cycle. (Reproduced with permission from STERIFLOW S.A.S.)

F0 (minutes) and Pressure (bar)

Sterilizing value F0

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Phase one Heating or come-up time (CUT): The temperature inside the retort is raised from room temperature to the specified sterilising temperature.

Phase two Temperature holding: The sterilising temperature is held inside the retort until the sterility of the product has been achieved. This is the holding time.

Phase three Cooling: The temperature of the retort has to be lowered from the sterilising temperature to something approaching room temperature. During the whole cycle, the temperature has to be accurately controlled. But the pressure inside the chamber has to be controlled as well. The goal is to permanently balance the pressure inside the cans and inside the retort in order to avoid damage to the integrity of the cans. If the pressure differential between the can and the retort is above a certain limit, there are two potential risks: 1. Peaking occurs when the pressure inside the can is much higher than the pressure in the retort resulting in deformation of the seam and risk of recontamination of the product, after sterilisation phase. 2. Panelling occurs when the pressure inside the retort is much higher than the pressure in the can resulting in deformation of the body of the can and poor appearance. The can suppliers are, generally speaking, able to specify the maximum pressure differential which can be borne by a can. With strong cans (small volume or heavy gauge tin) peaking and panelling are not normally critical considerations. But with fragile cans (large diameter – light gauge tinplate or aluminium) the acceptable pressure differential becomes more stringent. Temperature and pressure control are two fundamental concerns for a retort.

Sterilization of a canned product Sterilisation of a given product can be achieved by holding its temperature above 100◦ C for an appropriate time. A sterilisation cycle always refers to both temperature and time. Exposure of a product to a temperature above 100◦ C for a certain time results in the accumulation of a sterilising value called the F0 (F zero) value (see Figure 8.2). The suitable time/temperature combination or F 0 value required for a given product depends, amongst other things, on the initial microbial loading and the nature of the microorganisms. If the initial count is high, the F 0 value required is high. If the count is low, the F 0 value required is lower. This is why each canner is required to carry out heat penetration tests and repeat them until the suitable thermal process able to provide the degree of sterility required has been validated. The F 0 value required may be achieved by either using a high temperature and short time, or with a low temperature and longer time. With any time/temperature combination, it is possible to reach the required sterility but the quality of the products after sterilisation may vary accordingly.

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Sterilising values F0 with z = 10°C (18°F) Temperature (°C) 100 100.5 101 101.5 102 102.5 103 103.5 104 104.5 105 105.5 106 106.5 107 107.5 108 108.5 109 109.5 110 110.5 111 111.5

Fig. 8.2

F (minutes) 0.007 0.008 0.009 0.01 0.012 0.013 0.015 0.017 0.019 0.021 0.024 0.027 0.03 0.034 0.038 0.043 0.048 0.054 0.061 0.069 0.077 0.086 0.097 0.109

Temperature (°C) 112 112.5 113 113.5 114 114.5 115 115.5 116 116.5 117 117.5 118 118.5 119 119.5 120 120.5 121 121.5 122 122.5 123 123.5

F (minutes) 0.122 0.137 0.154 0.173 0.194 0.218 0.244 0.274 0.308 0.345 0.388 0.435 0.488 0.548 0.615 0.69 0.774 0.868 0.974 1.093 1.226 1.376 1.544 1.733

Temperature (°C) 124 124.5 125 125.5 126 126.5 127 127.5 128 128.5 129 129.5 130 130.5 131 131.5 132 132.5 133 133.5 134 134.5 135 135.5

F (minutes) 1.944 2.181 2.447 2.746 3.081 3.457 3.88 4.353 4.885 5.482 6.15 6.901 7.742 8.687 9.747 10.94 12.269 13.774 15.455 17.331 19.455 21.834 24.509 27.464

F 0 – sterilising value – table. (Reproduced with permission from STERIFLOW S.A.S.)

Examples of time/temperature combinations, measured at the core of the product, which lead to F0 value 10:

r r r r

41 minutes at 115◦ C or 10 minutes at 121◦ C or 3.2 minutes at 126◦ C or 1.3 minutes at 130◦ C

Important notice: The temperature taken into consideration for the F0 value calculation is the temperature at the slowest heating part of the product (the core in the case of canned fish products). This is why, when launching a new product, it is first necessary to validate the suitable F 0 value and then to validate the best time/temperature combination that will secure the quality of the product. These fundamental considerations are useful in providing a good understanding of the manner of operation of the types of retort.

8.2.2 Saturated steam retort family This is the original system used by Appert in the beginning of heat-sterilised foods. The use of this type of retort is now declining, although a significant number of them are still in operation worldwide and used daily. The chamber may be either vertical or horizontal and is generally made of mild steel.

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How does it work? At the beginning of the sterilisation cycle, saturated steam is injected into the chamber causing air, originally contained inside the chamber, to be pushed out in a process known as venting. This phase is called the venting time. When 100% of the air has been vented, and the temperature of the retort has been raised to its scheduled value, the holding time starts. Steam is continuously provided to the chamber in order to keep the pressure (and consequently the temperature) constant. At the end of the holding time, the steam supply is shut, the pressure inside the chamber is released and cold water is injected into the chamber for cooling. This is the cooling time.

Advantages of the saturated steam retorts The temperature control is very simple. For a given saturated steam pressure inside the chamber, there is an equivalent fixed temperature which can be read from steam tables. One bar pressure is equivalent to 120◦ C, 2 bar pressure is equivalent to 133◦ C, 2.5 bar pressure is equivalent to 147◦ C and so on. The equivalence between steam pressure and temperature is entirely fixed assuming that the steam boiler and steam network are supplying saturated steam with no entrained air or liquid phase.

r

The temperature distribution inside the chamber is uniform, provided the air venting has been effective and there is no residual air inside the chamber during the holding time phase.

Air or air pockets in the chamber are the biggest enemies of an efficient heat transfer and good temperature distribution during the holding time phase. Localised pockets of air will cause localised lowering of temperature.

r

The temperature control is extremely simple. In theory a steam pressure gauge would be sufficient, although in practice mercury in glass (MIG) thermometer is legally required.

Critical factors of saturated steam retorts

r r r r

Air venting must be perfect. Otherwise, there will be air pockets inside the chamber resulting in poor heat exchange, poor temperature distribution, temperature reduction and the possibility of under sterilisation. The steam transfers its heat to the cans by the process of condensation releasing relatively large quantities of latent heat in the process. Hot air, in contrast to steam, transfers heat to the cans only by conduction. Approximately ten times less energy is transferred than steam at the same temperature. Steam or energy consumption is high. During the venting phase, a significant quantity of steam escapes through the venting valves and is lost. In addition, there is normally a bleeder open permanently on the upper part of a steam retort during the holding phase in order to make sure that steam is circulated and any air is continuously evacuated. This is an additional steam loss. There is no overpressure control. This is probably the main handicap of saturated steam retorts. At the very beginning of the cooling phase, the temperature inside the cans is equal to the sterilisation temperature. Therefore, the pressure inside the cans is high. This pressure is equivalent to the sum of: – The steam pressure at the temperature of sterilisation; – The head space pressure, made of air, which has expanded with increasing temperature; and – The pressure of any gas contained by the product.

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Steam inlet

(a)

Fig. 8.3

(a): Vertical saturated steam autoclave. (Reproduced with permission from STERIFLOW S.A.S.)

As a result at the end of the holding phase the pressure inside the can remains high while the pressure in the chamber drops quickly to atmospheric pressure. There is a consequent risk of peaking. The current remedy consists of injecting compressed air into the chamber in order to reduce or cancel the pressure differential between can and chamber.

r r

High cooling water consumption. During the whole of the cooling phase, cold water is provided to the chamber and discharged to the drain. The lack of overpressure control combined with the direct injection of cooling water into the chamber increases the risk of recontamination to the previously-sterilised cans. This is why the direct cooling necessitates in practice the use of chlorinated water.

8.2.3

Full immersion retort family

The heat exchange medium is hot or superheated water and the cans are totally immersed in water during the three phases of the retort cycle. In the past, there were a number of full immersion retorts designed with a vertical chamber, but these have now been discontinued. The water and energy consumption were too high, and in addition, temperature distributions tended to be very poor.

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(b)

Fig. 8.3

(b): Full water immersion autoclave. (Reproduced with permission from STERIFLOW S.A.S.)

Until mid-twentieth century, the only retorts available were the saturated steam and vertical full immersion systems. In about 1950, the German company STOCK developed and launched a horizontal full immersion retort equipped with a rotary drum inside the chamber, under the name of ROTOMAT. Such a design included a number of significant innovations (see Figure 8.3): 1. 2. 3. 4. 5.

Horizontal chamber Rotary drum Energy saving Overpressure control Fully automatic cycle

Compared with the traditional vertical retorts used during the previous 150 years, the ROTOMAT provided a definite improvement. The horizontal chamber made basket handling simpler by obviating the need to install a hoist system above the retorts. As pointed out previously, the temperature distribution with a full immersion retort is problematic. The reason is that water circulation throughout the chamber or throughout the cans stacked in baskets may not be even resulting in temperature differences (or cold spots) from one zone to another. STOCK found that stacking the cans inside a rotating drum itself installed inside the chamber greatly improved the temperature distribution inside the chamber. At a speed of 6–12 RPM, the rotary drum acts as a water mixer. The second huge innovation provided by this rotary drum is called end over end (EOE) rotation. The cans, stacked upright in the baskets, are inverted twice with each rotation of the drum, thus generating agitation inside the cans or forced convection significantly accelerating the rate of heat penetration into the cans.

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It is to be noted however that forced convection is only applicable to liquid products (so-called convective products). If the products to be sterilised are solid (or conductive), there is no agitation inside the cans and rotation does not really bring any benefit.

Energy saving With an ordinary full immersion retort, the chamber is first filled with cold water, the water is heated up by steam injection and at the end of the holding time, the chamber is drained and the hot water is lost. This is a waste of energy. The ROTOMAT, in contrast, includes two chambers: the process chamber and the hot water recovery tank located above the process chamber. At the end of the sterilising phase, hot water is returned to this upper tank.

Overpressure control Can peaking and panelling of cans are two potential risks when operating a retort which is not equipped with an overpressure control system. One of the innovations provided by the ROTOMAT system was the provision of overpressure control as standard equipment. Fully automatic control: During a sterilising cycle, three main parameters have to be accurately controlled:

r r

Temperature and time which secure the sterility of cans Pressure which secures the structural integrity of the cans (or any other type of container)

From the origin, the ROTOMAT was provided with a control panel including a temperature controller, a pressure controller and timers by which the sterilisation programme was automatically controlled. Years later, a perforated card programmer replaced the previous system, itself being rapidly replaced by computer and PLC programmers. Nowadays all type of retorts are automatic and programme controlled.

How does it work? The chamber having been loaded and the door closed, the cycle starts. The hot water preheated in the upper hot water recovery tank flows down to the process chamber and fills it. Rotation starts. Steam is injected into the process chamber until the sterilisation temperature is reached and the holding phase starts. At the end of the holding phase, cold water is injected into the process chamber and pushes the hot water up to the recovery tank. Around 80% of the hot water is thus recovered. When the upper tank filling is completed, the cooling phase starts and the process chamber is continuously fed with cold water which is directed to the drain. At the end of the cooling phase, the rotation stops and the cycle is complete.

Critical factors of full immersion retorts with rotation

r r

If rotation fails for one reason or another during the cycle, the temperature distribution is disturbed. Sterility will be compromised if rotation fails since the heat penetration will be greatly reduced with convective products.

Critical factors inherent to rotation itself

r

Rotation creates forced convection inside the cans only if the product is liquid and if there is a headspace available. The amount of convection varies with the volume of the headspace (or filling Level). Therefore, it is essential to make sure that the cans are all filled to a constant level.

Retorting machinery and heat-sterilised fish products

8.2.4

187

Steam/air retort family

In about 1970, another innovation appeared in the world of autoclaves: a steam retort with an overpressure control, developed by the French company, LAGARDE. This represented a real innovation since overpressure control was previously not possible on saturated steam retorts. The idea included the installation of a fan (or turbine) at the back of a horizontal chamber able to mix the steam and the air required for overpressure. The steam/air retort was born and today represents one of the important systems used by the canning industry. The heat exchange medium of the steam/air retort is a uniform mixture of air and steam marking the difference to a saturated steam retort commonly called a ‘pure steam retort’. Saturated steam is a gas whose physical properties are well known. Steam/air mixture is another type of gas with different thermal properties. In simple terms, a steam/air mixture delivers less energy than pure saturated steam, depending upon the steam/air ratio.

Operation of a steam/air retort (see Figure 8.4) The retort having been loaded and the door closed, the fan is powered and the steam is injected into the chamber. The temperature and the pressure inside the chamber are raised up to their scheduled values using automatic programmed control. Depending upon the pressure required during the

Air/steam process

Cooling water inlet Cooling water outlet Vacuum breaker

Venting valve

Compressed air

Steam injection Water make-up

Drain Fig. 8.4

Design: STERIFLOW SAS MCI

Schematic of an air/steam autoclave. (Reproduced with permission from STERIFLOW S.A.S.)

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CUT, either the air originally contained in the chamber is partially vented, or fresh compressed air is injected. In either case, the fan is used for thorough mixing of the gaseous mixture, whatever the ratio is. Once the come-up phase is over, the holding phase may start as soon as the scheduled sterilising temperature and a uniform temperature distribution have been obtained. This is achieved on an average within 8–12 minutes. During the holding phase, steam is injected in order to hold the set sterilising temperature and the programmed pressure is controlled either by air injection or by air exhaust. When the holding time is over, the cooling phase starts. The steam supply is shut off and cold water is injected into the chamber through a number of water jets, which create a mist of cold water, and the steam/air mixture is vented. At this very moment, the pressure in the chamber has a tendency to drop rapidly and compressed air must be injected in order to compensate this pressure drop. Pressure control at this stage is essential for two reasons: 1. To avoid peaking of the cans. 2. To avoid the creation of a vacuum inside the chamber which can occur if cooling is too fast and the air supply too low. Fresh cold water is provided to the chamber through the water jets during the whole of the cooling phase before being discharged to the drain. The cooling phase is complete when the programmed final cooling temperature has been reached and pressure is equal to the atmospheric pressure.

Advantages of steam/air retorts

r r

The overpressure control from compressed air is effective during the whole cycle facilitating the control of container integrity, and the fan prevents air pockets or cold spots developing during the holding time. Lower steam consumption, compared with pure steam or full immersion retorts.

Critical factors of steam/air retorts

r r

The fan operation is critically essential. If for some reason, the fan fails during the holding time, there is no agitation of the steam/air mixture leading to air pockets, uneven temperature distribution and the possibility of under sterilisation. A high flow rate of compressed air is required at the beginning of the cooling phase to compensate the rapid pressure drop in the chamber and to avoid peaking of the cans.

Steam/air retorts are available either as static or in rotary versions. The sterilising cycle is always fully automatic and monitored by a programming unit based on PLC or microprocessor control.

8.2.5

Water spray air/steam retorts

In about 1985, a variant of the steam/air retort was invented and developed by the Spanish company SURDRY. Instead of using a powerful fan required on the Lagarde system for mixing air and steam, SURDRY had the idea of applying the air-turbulence effect caused by forcing pressurised water through a series of jets. It is understood that the penetration of water at high velocity through ambient air creates a strong turbulence within the air. This physical phenomenon is used by the Surdry Company to provide mixing of the steam/air mixture inside the chamber of a retort.

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Water spray process Steam preheating Cooling water inlet Cooling water outlet Vacuum breaker Compressed air

Steam injection Water make-up

Drain Fig. 8.5

Design: STERIFLOW SAS MCI

Schematic of a water spray autoclave. (Reproduced with permission from STERIFLOW S.A.S.)

How does it work? (see Figure 8.5) During operation, a small volume of water stored in the bottom of the retort is pumped and recycled through a number of water jets which deliver sprayed water to the sides and the top of the baskets. For heating, steam is injected into the chamber, and air for overpressure control. The steam and air are evenly mixed together by the turbulence. Heat is transferred to the product mainly by the condensation of the steam in contact with the outer surface of the cans. However, the sprayed water, which is at the same temperature during the holding phase as steam, is also providing heat to the product. With the exception that water jets are used instead of a mechanical fan, the operation of the steam/air retort and the water jet spray retort are very similar

Critical factors of the water jet air/steam retort In both types of steam/air retorts, the steam/air-mixing device is critical. The water jet mixing operates efficiently under two conditions: 1. The flow rate and discharge pressure of the pump feeding the water jets must be correct and constant. Otherwise, the grade of turbulence may become too low for securing adequate steam/air mixing and the required uniform temperature distribution. 2. All water jets must be clean and clear. If some of them are plugged by dirt or particulates, the efficiency of the turbulence effect is reduced and temperature distribution may be deteriorated. The main suppliers of water spray steam/air retorts are SURDRY in Spain and JBT in Belgium. Both types of steam/air retorts are available in static or rotary versions.

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8.2.6 Cascading water retorts In 1975, a totally new and innovative system was developed in France. There were three novel features: 1. To use the energy of steam or cold water indirectly, via a heat exchanger, rather than by injecting these two media directly into the process chamber, as happens in saturated steam, full immersion or air/steam retorts. 2. To use circulating hot and cold water in turn as the heat exchange medium and to shower the water on the cans rather than immersing them. 3. To manufacture this new generation of retorts in stainless steel, instead of mild steel as had been the case during the two previous centuries. The cascading water retort was born; the system was patented, and registered under the name of STERIFLOW. Since then, the French company STERIFLOW has continued to produce and successfully sell this type of retort worldwide (see Figure 8.6). The key parts of the STERIFLOW retort are:

r r

The chamber fabricated from stainless steel The very special heat exchanger

Fig. 8.6

Water cascade autoclave STERIFLOW. (Reproduced with permission from STERIFLOW S.A.S.)

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Cascading water process

Steam inlet Cooling water inlet Warm water outlet Condensates outlet Compressed air inlet Compressed air outlet

Water make-up Drain Design: STERIFLOW SAS MCI

Fig. 8.7

r r

Schematic of a water cascade autoclave. (Reproduced with permission from STERIFLOW S.A.S.)

The recycling pump capable of providing a high flow rate for the circulating water The water spreader

The operation of the STERIFLOW retort (see Figure 8.7) Heating and sterilisation phases The small volume of water in the base of the retort is circulated through the heat exchanger where its temperature is raised to the scheduled value. It is then showered at a very high flow rate over the containers. The opening of the heating valve that allows ingress of steam to the heat exchanger is controlled to provide to the pre-programmed temperature value to the circulating water. Condensates are evacuated via a steam trap and can be returned to the boiler. The overpressure within the retort is regulated independently from the temperature by the injection, or exhaust, of compressed air according to the pre-programmed pressure values. Cooling phase The cooling water supplied to the heat exchanger is entirely separate from the circulating water in the retort and cannot soil or re-contaminate the containers. This in principle means that any kind of water can be used for cooling. If potable water is used it will exit at a warm temperature from the heat exchanger and can then be reused if required, as it will still be in a potable state. The circulation of cold water through the heat exchanger is controlled automatically in relation to the programmed cooling curve. The variable flow rate of the cooling water through the heat exchanger does not influence either the homogeneity or the transfer coefficient on the surface of the containers as the quantity of water in contact with the containers always circulates at the same rate. The pressure is controlled exactly as during the heating phase. In the case of glass containers, all risks of thermal shock are eliminated.

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The containers are cooled with water that has itself been sterilised.

End of cycle At the end of the cooling phase the circulating pump stops, the quantity of water collects at the bottom of the vessel and the vessel is reduced to atmospheric pressure. The containers may now be removed. Advantages of the STERIFLOW cascading water system r The heat exchange media (steam or cold water) are never in direct contact with the containers to be processed inside the retort. r The system allows 100% of the steam condensates to be recovered and returned to the boiler. r No thermal shocks when cooling which eliminates the risk of breakage of glass containers. r The cooling water and circulating process water are separated. Therefore, the cooling water cannot re-contaminate the sterilised product. In fact cooling is achieved by the circulating process water, which has itself been sterilised together with the product during the holding phase. r As the cooling water is not in contact with the product, chlorination of the cooling water is not required, and any source of non-potable water, such as river, lake or atmospheric cooler water, may be used. r At the exit of the heat exchanger the cooling water is warm and this heat may be easily recovered. r The feed pressure of the cold water to the heat exchanger does not depend on the pressure inside the chamber. No booster pump is required. r The discharged cooling water is not polluted and may be recycled. Critical factors of the STERIFLOW r The heat exchange medium is the cascading water. Consequently the water spreader must be kept clean. The water spreader is basically a perforated plate installed over the baskets. It must be regularly inspected to make sure that the holes of the perforated plates are not plugged by dirt. Plugging of the holes may result in cold spots leading to the possibility of under-sterilisation. r The flow rate of the recycling centrifugal pump is essential. The temperature distribution is secured by the velocity of the water cascading from top to bottom through the baskets. A reduced flow rate can be caused by two reasons: cavitation due to low process water level or wearing of the impeller of the pump. As with other types of retorts, STERIFLOW retorts are available in static and rotary versions.

8.2.7

Other retorting systems available

For completeness it is useful to mention some other specific batch retort systems that are currently available. 1. Small size retorts dedicated to research and development (see Figure 8.8): In practice all retort suppliers are able to offer a laboratory retort intended for the R&D department of canneries, for universities or for institutes. These are small scale retorts, fully automatic in operation, programme controlled and specially designed for developing and validating all the parameters relative to the sterilisation cycle of a given product: – The time/temperature combination to achieve product sterility (heat penetration tests) or determination of the appropriate F 0 value;

Retorting machinery and heat-sterilised fish products

Fig. 8.8

193

Laboratory-scale autoclave diameter 900 mm. (Reproduced with permission from STERIFLOW S.A.S.)

– – – – –

The evaluation of the quality of the product after sterilisation; The determination of the most suitable overpressure curve; The evaluation of the possible benefits of processing in the rotary mode; The evaluation of heat and pressure effects on a container; and The adjustment of the recipe of a canned product. A number of reactions regarding the products and the containers are unpredictable and must be subject to experimental trials before launching a new canned product. All parameters may be collected and validated using a pilot or laboratory unit and then re-used on an industrial retort. Some laboratory units are relatively simple in that they simulate only one type of operation – saturated steam, full immersion or cascading water. Others are able to simulate any type of batch retorts, in static or rotary mode. 2. Beside the static and rotary retorts, there is also the shaking system. 2.1 EOE rotation is excellent for creating agitation or artificial convection inside a can or any sealed container. However, the cost of a rotary retort is high in terms of both the initial capital expenditure and subsequent maintenance. Another system, which is simpler and cheaper, called the DALI system, has been developed by the STERIFLOW company. The baskets lie on a conveyor, inside the chamber, which moves

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backward and forward. This conveyor starts and stops about 12 times per minute. The acceleration developed during each start-and-stop motion creates an agitation or artificial convection inside the container. However, this system is efficient only for liquid products. The most popular application is for the sterilisation of white or flavoured milk filled in plastic bottles. 2.2 In 2005, a British engineer experimented and developed the SHAKA retort. The principle consists of agitating the baskets inside the chamber using an external crankshaft drive system. The basket, together with the product, is shaken at a high frequency of 100–180 cycles per minute which creates a tremendous artificial convection. As a result, the heat penetration within the containers becomes very rapid – between 5–6 times faster than with EOE rotation. Sterilisation is achieved within a very short time and the quality (taste–colour) of the finished product is definitely improved. However, the SHAKA system is applicable only to liquid and semi-liquid products. Retorts based on SHAKA system are available from two suppliers: STERIFLOW France, ALLPAX USA.

8.2.8 Continuous retorts After having described the principal types of batch retorts, it is useful to also mention continuous retorts. These are basically used for the large-scale production of a single product or single size of can. For this reason it is unusual for continuous retorts to be used in fish canneries which are mostly required to produce several different products simultaneously possibly filled into several sizes of cans. 1. Vertical continuous retorts: Also called hydrostatic sterilisers or sterilisation towers. They include three sections: preheating, holding and cooling. The cans held in horizontal carrier tubes travel up and down inside successive vertical columns. The heat exchange media are hot water for preheating, steam for holding and cold water for cooling. The steam pressure (which determines the temperature) inside the holding section is balanced by the height of the water column of the preheating and cooling sections. As an example, in a 15-m high water column, the steam pressure will be 1.5 bar, equivalent to 127◦ C. To adjust the sterilising temperature, it is necessary to adjust the water level in the hydrostatic columns. The holding time is proportional to the travelling time through the holding section. The speed of the carrying chain supporting the carrier bars determines the holding time. In practice for construction and mechanical reasons, the maximum operational temperature is 129◦ C (1.64 bar or 16.4 m high). The holding time may be adjusted, the upper and lower limits being within an approximate ratio of 1 for the shortest time to 8 for the longest time. Three suppliers effectively share the world market for this type of technology: STORK Holland, JBT USA and STERIFLOW France. 2. Horizontal continuous retorts: 2.1 The most popular horizontal continuous retort is the STERILMATIC, Reel and Spiral system produced by JBT (also called Cooker/Cooler). Such machines comprise a minimum of two horizontal chambers, one for heating and the second one for cooling. Inside each chamber, there is a rotary reel which propels cans around a spiral track on the inside walls of the vessel. The chambers are under pressure. Cans are consequently introduced into the chambers, and then extracted, by rotary valves (or steam locks). They enter at one end and leave at the other.

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In the lower portions of the chamber the cans are being pushed along the reel and experience a high rate of axial rotation. This axial rotation accelerates heat penetration by creating some agitation inside the product provided that the product is liquid or semi-liquid. The sterilising chamber is heated by injection of saturated steam while the cooling chamber is fed with cold water. 2.2 Another well-known horizontal system is the HYDROLOCK produced by ACB France. This is basically a large horizontal chamber inside which the cans are travelling in cylindrical carriers moved by a chain. The upper part of the chamber is filled with saturated steam. The bottom part of the chamber is filled with cold water. The can carriers are conveyed successively through the steam section and cooling section. The sterilising temperature is adjusted by steam pressure inside the chamber and the holding time is adjusted from the speed of the can carriers. The can carriers are rolling on guides all the way through the heating and cooling zones. Therefore, the cans lying horizontally inside the cylindrical carriers are also subject to axial rotation. Such axial rotation accelerates the heat transfer with liquids or convective products. As in the previously mentioned STERILMATIC machine, the chamber of the HYDROLOCK is under constant pressure and the cans are introduced into the chamber and extracted by means of a mechanical steam lock.

Advantages of the continuous retorts

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Labour saving. No manual can and basket handling as required with the majority of batch retorts; and Energy consumption per can is lower than with a batch retort.

Critical points of the continuous retorts

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Practically only suited to high capacity productions; Limited flexibility in terms of products and can sizes compared with batch retorts; and High capital expenditure. This is without doubt the main obstacle in using a continuous retort. It has to be built for a given production capacity and there is no extension possible in excess of this capacity. In other words, a canner who wishes to launch a product at low capacity in a first instance and to later expand progressively according to the demands of the market has to invest in a continuous system sized from the outset for a hypothetical future and larger production capacity.

8.3 TECHNICAL FEATURES OF HORIZONTAL BATCH RETORTS

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They can be static or rotary in operation. However, rotary retorts are used only when absolutely necessary for securing the quality of the finished products (see Figure 8.9). The purchase price of a rotary retort is almost twice that of a static one, and the maintenance cost is around three to five times higher. In addition all canned fish products are solid packed and subject to conductive heating. Any rotation would bring little if any benefit in terms of increased heat penetration. In consequence rotary retorts are not used in practice at all by the canned fish industry. They can be of single door or double door type. The potential danger in a cannery is to send a complete basket from the filling/closing area straight to the packaging area without going through the retort. This is indeed physically possible with a single door retort. When using a double door retort, all baskets are forced to go through the chamber of the retort before being directed to the

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Fig. 8.9 S.A.S.)

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Rotary water cascade autoclave diameter 1800 mm. (Reproduced with permission from STERIFLOW

packaging area. The double door retorts, although more expensive, are commonly used by the fish canners. Construction material: Nowadays all retorts are made of 304 stainless steel or sometimes from 316L stainless steel. This has eliminated rusting and the corrosion which slowly diminished the wall thickness and the pressure resistance of the retort chamber. A retort is a pressure vessel which must be built in accordance with very stringent rules and which has to comply with the construction codes specific to almost every industrialised country. A construction code specifies: – The rules of resistance calculation according to the operating pressure – The welding procedures – The qualification of welders – The radiographic control of weldings – The temperature and pressure safety devices – The pressure test procedure A pressure vessel is considered as being potentially dangerous. Therefore, it has to be absolutely safe for the personnel even in case of incorrect utilisation and after many years of service. Certain countries require that operators of pressure vessels are suitably trained and licensed. Some examples of construction codes are: – CE for European Union – ASME for USA – GOST for Russia – SELO for China Many countries have not developed their own specific construction code, but legally require the adherence to one of the recognised international codes.

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This matter of construction code has a number of consequences: – The retort supplier is liable in case of observed non-conformity in relation to the construction of the vessel. – The retort supplier must deliver, together with the retort, a technical passport including the chamber drawings, calculation notes, pressure test certificates, welding procedures etc. which must be kept carefully by the user during the whole life of the retort. – The user must declare to the local authorities the installation of a new pressure vessel and obtain from them a utilisation licence. – A retort built according to CE code cannot be used for instance in New Zealand without legal formalities consisting of converting the CE code into the national code of New Zealand. This matter is of great importance for buyers of second-hand retorts. – According to the CE code, a retort has to be pressure tested every 10 years to make sure that there are no cracks or stress corrosion on parts of the chamber or the door. This has to be accomplished in compliance with a very strict procedure by authorised experts. Working pressure and temperature: In general, all horizontal retorts are designed and built to withstand a maximum pressure of 5 bars. The maximum operating temperature is linked to the maximum pressure according to the equivalence between steam pressure and steam temperature. Five-bar steam pressure is equivalent to approximately 155◦ C steam temperature. However, the practical upper limit of a sterilisation temperature is rarely over 135◦ C. Fish products are generally sterilised at temperatures varying from 110 to 125◦ C. Size of horizontal retorts: Suppliers offer a wide range of retorts whose volume or capacity of the chamber varies according to the design output of the process lines. The size of a retort is defined by its diameter and the length of the chamber or number of baskets. For a given diameter, several chamber lengths are available. The main parameters to be taken into consideration for sizing a retort or the capacity of one batch include: – The production capacity in cans per minute (CPM); – The total cycle time (CUT + holding time + cooling + chamber loading/unloading time). The capacity of one batch = output in CPM × total cycle time in minutes. – The maximum acceptable standby time, i.e. the maximum time between closing of the first can of the batch and the start of the sterilising cycle.

This time is determined by the quality control department or microbiology department. It has been previously explained that the F0 value required for a given product depends upon the level of microbial contamination (or count) of the product at the time of filling the can. If the can waits too long after seaming and prior to sterilisation, the count may grow very significantly and the F0 validated for a lower count may become too small. There is also the danger of pre-process spoilage with subsequent loss of product quality. This parameter of standby time is important in the canned fish industry and in practice determines the maximum capacity of a batch. Maximum capacity of a batch = output in CPM × total cycle time in minutes. Example: output of the line: 60 CPM Total cycle time: 90 minutes Maximum waiting time: 40 minutes Without reference to the standby time, the suitable size of a batch would be: 60 CPM × 90 minutes = 5400 cans. If the maximum standby time is considered, however, the batch capacity becomes: 60 CPM × 40 minutes = 2400 cans only.

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The suitable size of the batch having been calculated, it remains to choose the diameter and the length of the retort. Typical combinations available are: – Ø 1300 – chamber length available from 1 to 7 baskets – Ø 1450 – chamber length available from 3 to 6 baskets – Ø 1600 – chamber length available from 4 to 6 baskets – Ø 1800 – chamber length available from 4 to 6 baskets – Ø 2000 – chamber length available from 4 to 6 baskets In reality the purchase cost of a retort is largely determined by its diameter. This is why the choice is normally made for the smaller diameter. Example: – Required capacity of the batch: 5400 cans – Capacity of a basket dedicated to a dia. 1300 chamber: 1200 cans – Capacity of a basket dedicated to a dia. 1450 chamber: 2000 cans = 4.5 or 5 baskets – Length of a dia. 1300 chamber: 5400 1200 5400 – Length of a dia. 1450 chamber: 2000 = 2.7 or 3 baskets In practice the dia. 1300 – 5-basket chamber would be selected because it would be significantly cheaper than a dia. 1450 – 3-basket model. If the standby time is not an issue, it is strongly recommended to select, for a given diameter, a chamber oversized in length. For relatively limited extra cost, an extension of output is available for the future, which extends the time when it might become necessary to purchase a second retort. In practice the most common size of retort used by the canning fish industry is by far the dia. 1300 with 5 or 6 baskets.

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Size of baskets: Cans after filling and seaming are put into baskets (also currently called crates) themselves lying on trolleys. The basket, after completion of loading, must be moved towards the retort, and then pushed inside the chamber of the retort. Such a loading operation is generally accomplished by one operator. This is why there is a limit in terms of the total weight of a basket and trolley assembly. It is recognised that the reasonable maximum weight for an operator is 450 kg. This is precisely the weight of a basket dedicated to the dia. 1300 retorts. And this is another good reason why the dia. 1300 retort is so popular.

With a dia. 1450, the weight of the basket and trolley assembly climbs over 600 kg, which is the absolute upper limit for manual handling of baskets. With bigger diameter than 1450 mm the baskets are so heavy that a mechanised and automatic basket handling system is required. These will be described below.

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Safety devices: All major suppliers of batch retorts are required to manufacture in compliance with the construction code of the country where the buyer wishes to deploy the equipment. Whatever the construction code, the safety rules regarding the construction and utilisation are basically the same. 1. Safety rules regarding the construction – Calculation notes, welding procedures and welder qualification as per the construction code – Pressure tests and legal stamp as per the construction code 2. Safety rules regarding the utilisation 2.1. For the security of the person – It must be physically impossible to open the door if the pressure inside the chamber has not been totally released down to atmospheric pressure. – It must be physically impossible to open the door if the temperature inside the chamber is over 80◦ C, even if the pressure is zero.

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– One or two calibrated pressure relief valves must be fitted which will prevent the pressure being in excess of the legal working pressure of the chamber. – No accessible parts of the chamber must be hotter than 100◦ C during the sterilisation cycle. 2.2. Instrumentation to ensure that the sterilising process is in compliance with the set sterilising programme: – The chamber pressure must be clearly indicated on a visible pressure gauge. – The temperature inside the chamber must be clearly indicated on a master thermometer of suitable specification, either MIG thermometer or Platinum resistance thermometer. The operator must be in a position at any moment during the cycle to compare the programmed temperature and the actual temperature indicated by the master thermometer. – A chart for recording both temperature and pressure inside the chamber must be in operation and the charts must be kept as long as the shelf life of the product. – Depending upon the sophistication of the control panel, some additional safety devices can be available such as: – Alarm in case of temperature deviation – Alarm in case of pressure deviation – Alarms in case of power cut and so on Control panel and programming unit: A retort is always provided with a control cabinet either located remotely or positioned over the door of the chamber (see Figure 8.10). The control panel includes: – The temperature/pressure recorder – The programming unit – All electrical and pneumatic components used for operating the valves, the pumps, the temperature probes, the pressure transducers etc. Nowadays, all brand new retorts are delivered with a programming unit based on microprocessor or PLC technology and including a display screen and keyboard. From the programme controller it is possible: – To write and store up to 50 or more programmes; and – To call up and to launch any programme.

Fig. 8.10

Control panel. (Reproduced with permission from STERIFLOW S.A.S.)

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The programmer will control the temperature, the pressure and the time and will also monitor the alarms in case of defective operation. Important remarks: – The pressure recorder and the programme controller are operating from the same pressure transducer. – However, the temperature signals delivered to the programme controller and to the temperature recorder must originate from two different and separate temperature probes. The recorder temperature probe must be positioned at the coldest point of the chamber which has been located during the temperature distribution tests. There is no specific requirement regarding the location of the programmer temperature probe. Most suppliers are offering as an option, in addition to the individual programming unit, a SCADA system (Supervisory Control And Data Acquisition). This is an industrial PC linked to several programming units, and able to collect and print all data available from the programmers. It can be also connected to an Ethernet type network for communication with the other departments of the cannery.

8.4 GENERAL ARRANGEMENT OF A STERILISING PLANT A sterilising plant includes all those equipments between filling/closing and packaging of the cans. When designing a sterilising plant, the appropriate technical solutions must be studied and selected to fulfil four different needs: 1. 2. 3. 4.

Basket loading Basket unloading Basket handling before and after sterilisation Sterilisation

8.4.1

Basket loading or loading station

There are two ways of loading baskets: 1. Scramble packed: This was very common in the past, especially in the fish canning industry and it is not unusual even today to see canneries which continue to use this system. The basket to be loaded is immersed in a water tank located next to the discharge conveyor of the seaming machine. The cans fall along a chute into the water and gently sink inside the basket. Immersion of the basket prevents the cans from being dented or otherwise damaged when falling from the seamer. Once the basket is full, it is lifted up from the water tank by a hoist. 2. Layer-by-layer loading: This is by far the universally preferred system. The problem with scramble packing is the operation of basket unloading. The only way is to tilt the basket, which is rather brutal, and may cause denting of cans especially when processing fragile containers such as aluminium cans. It also requires the unscrambling of the cans before labelling. The sophistication of a layer-by-layer basket loader depends on the output of the line. 2.1 Manual layer-by-layer loading (also called basket bottom elevator) – see Figure 8.11 The basket and its trolley are put over a hydraulic lift. The mobile basket bottom plate is lifted up to the upper edge of the basket. The cans are then fed on a conveyor from the seamer and are manually placed side by side on the bottom plate. When the first layer is completed, the lift is

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Fig. 8.11

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Basket bottom elevator. (Reproduced with permission from STERIFLOW S.A.S.)

lowered and a plastic layer pad is put in place. The operation is repeated until the basket is fully loaded. The layer pads (or dividers) are perforated in order to allow the circulation of the heat exchange medium. The layer pad material is polypropylene and the thickness is around 3 mm. 2.2. Semi-automatic basket loader: This equipment includes the hydraulic lift, an infeed conveyor and a layer former/pusher. – Putting the basket and trolley into place over the lift is a manual operation; and – Putting the layer pads into place is a manual operation. But the stacking of layers of cans is fully automatic. 2.3. Fully automatic basket loader (see Figure 8.12): In this case, everything is automatic – Putting the empty basket in place and the removal of the loaded basket are automatic; – The handling of layer pads is automatic; and – Arrangement and stacking of layers are automatic. Nevertheless, an operator remains necessary for feeding the machine with empty baskets.

8.4.2

Basket unloading or unloading stations

The basket unloaders are the reciprocal of the loaders. The range of equipment is similar.

8.4.3

Combined basket loader/unloader

When the layout of the plant makes it possible, it is advantageous to link the automatic basket loader to its homologue, the basket unloader. In this situation, the unloaded baskets are conveyed directly from the exit of the basket unloader to the inlet of the basket loader. The layer pads are also transferred automatically from the basket unloader to the basket loader magazine. With this configuration only one operator is required instead of two.

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Fig. 8.12

8.4.4

Fully automatic basket loader. (Reproduced with permission from LAN HANDLING SYSTEMS S.A.S.)

Basket handling

1. Manual: In small- or medium-sized plants, basket handling is manual and requires one or two operators dedicated to this job. The baskets of horizontal batch retorts always lie on trolleys. One trolley is required for each basket. The trolleys have four wheels making it possible to push both empty and loaded baskets across the floor as required. The baskets have to be moved for four different operations: – The baskets emptied by the basket unloader must be returned to the basket loading station. Sometimes the distance may be lengthy. – The loaded baskets have to be moved from the basket loader to the proximity of the retorts. – The operator must carry out the loading and unloading operations of the baskets into and out of the retort. The basket on its trolley is positioned in front of the door, and the operator has to push the basket inside the chamber. The trolley remains outside. When the cycle is over, the reverse operation takes place. The operator has to pull out the baskets, one by one, using a long rod fitted with a hook. As an option, some retort suppliers offer a dog chain conveyor installed inside the chamber, which facilitates easier and more comfortable loading and unloading. – Finally the sterilised baskets must be moved to the unloading station, possibly by way of a tilting station in order to remove any free water trapped in the countersinks of the cans. The baskets are tilted between 45 and 85◦ . 2. Fully automatic (see Figure 8.13): In large-scale production it is normal to install a ‘fully automatic basket handling system’. In this case all the steps of basket handling described above are mechanised and automated. Trolleys are no longer used to convey the baskets. Instead the baskets, either empty or loaded, travel at all times on conveyors.

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Fig. 8.13

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Fully automatic sterilisation installation. (Reproduced with permission from MECTRA S.P.A.)

– From the basket unloader to the loader – From the basket loader to the retorts via a shuttle – From the retorts to the basket unloader via the shuttle The basket loader and unloader are themselves fully automatic and the retorts are equipped with automatic doors. Such fully automatic sterilising plants are controlled by one operator only and are comparable to continuous retorts. They are called ‘continuous sterilising plants based on automated batch retorts’. The main suppliers of the automatic handling systems are LAN Holland – MECTRA Italy and JOERGENSEN Denmark.

8.5

UTILITIES REQUIRED FOR BATCH RETORTS

A retort is not a self-contained machine and requires connection to a number of external services including:

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Electricity Compressed air Saturated steam Cold water (potable process water + cooling water)

The initial step when buying one or more retorts is to check that all utilities are, or will be, available in sufficient quantity and quality. The cost of utilities, or the operating cost of a retort, is a serious matter for all canneries and must receive careful consideration at the outset. All retorts suppliers are able to provide accurate figures regarding the utility requirements of a given retort. From such data, all potential users should be in a position to calculate the operating cost per batch or per can. The cost of utilities however may significantly vary from one region or one country to another.

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8.5.1

Electricity

A three-phase, plus earth, supply is required and the power for an average size of retort is in the range of 4–15 KW. Attention should be given to the possibility of, over voltage, power cuts and micro cuts which may disturb the operation of the electronic control system.

8.5.2

Compressed air

Compressed air is required for operating the control valves and for providing the overpressure inside the chamber. Both pressure and the flow rate of the air supply are critically important. In case of defective supply, overpressure control is no longer effective possibly leading to the peaking of cans or bursting of flexible containers. Six-bar pressure is required within the compressed air distribution system of the factory. The required flow rate depends on the size of the retort. In order to guarantee the compressed air supply to a retort, the recommended solution is to install an air reservoir, big enough for the completion of one or several retort cycles. In the case of complete failure of the factory supply, the reservoir will provide enough compressed air for the operation of valves, the controlling of overpressure and in short, the saving of the cycle or cycles in progress. The retort suppliers are able to advise the users about the suitable size of the air reservoir. It is strongly recommended that air should be oil-free.

8.5.3 Steam All types of retort require steam for heating at a maximum pressure of 6 bar. Most steam boilers produce steam at 8–10 or 12 bar. Therefore a suitably sized steam reducer must be installed on the retort steam supply line. The steam supply to the retort should not exceed the specified safe working pressure of the retort – this being valid only for direct steam injection autoclaves. The steam demand or instant flow rate depends on several parameters:

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The load of product inside the chamber and the size of the retort Initial temperature of the product Specific heat of the product The anticipated CUT

The steam demand is proportional to the temperature difference (Delta T) between the chamber and the product. Therefore, the steam demand is the highest at the very beginning of the CUT and decreases slowly until the product temperature is equal to the chamber temperature. The available steam flow rate is therefore critical only during the CUT. This also explains why in some canneries the CUT is longer than it should be because:

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The steam flow rate is low The steam pressure is low

The steam pressure also has an influence on the duration of the CUT. The quantity of energy transferred to the product by the latent heat of condensing steam is proportional to the steam pressure.

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In estimating the size of boiler required the maximum steam load is given by the following formula: (Load of product (kg) × specific heat (SH) ×
T (◦ C) × 60) = steam flow rate (kg per hour) CUT (minute) × LH (steam latent heat) For more accuracy, this formula should include some reference to the weight of metal, the volume of water ballast (if any) and heat losses. Generally speaking, the programmed CUT is in the range of 8–12 minutes and the steam boiler should be sized accordingly. How to size the steam boiler when several retorts are installed side by side? Two situations are described. Example:

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Three retorts installed A–B–C Total cycle time: 75 minutes CUT: 10 minutes Holding: 40 minutes Cooling: 20 minutes Chamber loading/unloading: 5 minutes Steam flow rate required for one retort: 1.5 T/hour

Situation 1: The three retorts are used for the same product. Therefore, each retort will be loaded every 75/3 = 25 minutes. In other words, it will never happen that more than one retort is in a CUT situation and a boiler sized for one retort only is suitable. Situation 2: The three retorts are used for two different products produced simultaneously. Therefore, the retorts A and B will be loaded and will start at the same time. In this case the steam boiler must be sized for providing two retorts with steam at the same time. 1.5 T × 2 = 3 T/hour. This is the principle for the calculation of the total steam demand. However the situation becomes more complicated when a number of batch retorts are in production with four or five products each requiring different cycles. The only way to solve the problem is to draw a schedule chart and to see how many retorts demand steam simultaneously.

8.5.4

Cold water

Cold water is nowadays becoming the most critical and costly utility. The problem is double:

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Fresh water which has to be available and paid for The removal of waste water may be subject to taxation and may require suitable treatment prior to final discharge

This is why it is essential to minimise:

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The fresh cooling water consumption The volume of waste water The degree of pollution of waste water

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All retorts need cold water for cooling the product inside the chamber. However, depending upon the design of the retort, the cold-water issue is more or less critical. Case 1: Retorts with Direct Cooling: As explained above, many traditional retorts are designed for the direct injection of cold water into the chamber, resulting in the:

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Consumption of potable and chlorinated water; Wasteful discharge of water to the drain; Pollution of waste water doubly by organic and chemical materials (BOD and COD) and heat (in many places the discharge of waste water over a certain temperature is prohibited).

Case 2: Retorts with Indirect Cooling: Currently all retort suppliers are able to offer, either as standard or as an option, an indirect cooling system, or cooling through a built-in heat exchanger. The STERIFLOW company in France in 1976 was the first to deliver retorts including an external heat exchanger as standard. For all retorts, the principle is the same.

Primary circuit Water is recycled by a pump from the bottom of the chamber to the top of the chamber via an external heat exchanger. This is the loop of process water in direct contact with the product.

Secondary circuit Cold water passes through the heat exchanger but has no contact with the product to be cooled inside the chamber. The cold water transfers its heat to the circulating process water which itself transfers its heat to the cans. The indirect cooling system offers various possibilities for cost saving: 1. If potable water is the only source of cooling water available: – The addition of chlorine is unnecessary. – Warm potable water can be recovered from the outlet of the heat exchanger free of charge. – No pollution. The discharged water remains potable. 2. Use of non-potable water from river, lake, well etc. which can be returned without having been polluted. 3. Use of recycled cooling water from an atmospheric cooler (or cooling tower) which is by far the most popular solution. 4. Fish canneries are sometimes located on the seaside. Some of them use sea water for cooling. However, this requires a suitably designed Titanium heat exchanger able to resist hot salted water. 5. Other canneries are combining 1 and 3. The cooling phase starts with potable water which is diverted and recovered hot at the outlet of the heat exchanger. After a few minutes, the cooling is switched to the atmospheric cooler network. In conclusion, it is recommended to pay considerable attention to the cooling system. This provides the largest potential source of cost saving when using existing retorts or installing new retorts.

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207

THE DIFFERENT USAGES OF A RETORT

1. Sterilisation: The purpose is to achieve total destruction of microorganisms, and all spoilage organisms capable of growth in the designed ambient conditions for subsequent storage of the product. 2. Pasteurisation: Pasteurisation represents another type of heat treatment and at a lower temperature than sterilisation. It is used in the case of acidic products that will not support the growth of pathogens and which are intended for ambient storage, and it is also used for low acid products that are intended for relatively short shelf life at refrigerated temperatures. In the latter case, the purpose is to lower the microbial count and in particular eliminate the vegetative cells of pathogenic microorganisms after filling and closing. Temperatures used in pasteurisation are in the range of 80–100◦ C and, in principle such a process does not require a pressure vessel. However, many pasteurised products are filled in flexible containers which necessitate a small overpressure. If pasteurised products are intended for subsequent refrigerated storage it is necessary that they should be cooled down to less than 10◦ C as quickly as possible immediately after the heat process. When using a retort for pasteurisation, the programme includes two successive cooling phases: 1. Pre-cooling with normal cold water. 2. Final cooling (or chilling) with iced water at 1◦ C. This double cooling phase is possible only with a retort equipped with an external heat exchanger. 3. Cooking–cooling–chilling: Beside sterilised and pasteurised products, there are, what are currently called ‘sous-vide’ products. Such products are packaged raw, under vacuum, in a plastic bag before subsequent cooking and cooling (Sous Vide, in French means under vacuum). This group of products has been widely developed during the last 20 years and has become a significant application worldwide for retorts. Cooking temperatures vary from 65 to 95◦ C, which in principle does not require a closed pressure cooker. However, retorts are very commonly used for this application for two reasons: 1. Cooking under pressure brings some benefits. The product is permanently squeezed in its packaging film and this helps the process of heat transfer. There is no air cushion between the packaging film and the surface of the product to be cooked. 2. Sous-vide products, as pasteurised ones must be chilled to 4◦ C and stored at ≤ 4◦ C. Consequently, the pre-cooling and chilling facility available on retorts equipped with a heat exchanger is advantageous. Worldwide the STERIFLOW retorting system is the most popular system used for cooking– cooling–chilling of ‘sous-vide’ products.

8.7

LEGAL STEPS TO BE TAKEN WHEN INSTALLING A NEW RETORT

1. The first step when installing a new retort is to declare it to the local authorities responsible for the security of pressure vessels. The inspector will verify that the design and the construction of the retort are in full compliance with the national rules and will deliver a utilisation licence. In case of non-conformity, the licence will be refused and the retort user will have to ask the retort supplier to modify and fix the defective points.

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Fig. 8.14 Examples of products and packages that are sterilised nowadays. (Reproduced with permission from STERIFLOW S.A.S.)

2. Once the utilisation licence has been delivered, the retort may be commissioned for use. Before launching industrial production, however, the user should carry out all necessary validation tests. In the United States such validation procedures are compulsory. In the rest of the world they are strongly recommended. The US FDA (Food and Drug Administration), as a worldwide authority, expresses a double demand: 1. All canned products processed on the national territory must be FDA approved. 2. All imported canned products must also be FDA approved before entering the US territory. The US FDA concern is to ensure that canned products available on the US market – produced locally or imported – are safe for the consumer. It is important to recall that FDA never delivers an approval for a retort. The approval is delivered only for the canned product processed by a given retort on which validation tests have been carried out according to the guidelines developed by FDA. The FDA approach is very clear: a canned product will be considered as safe for the consumer provided that all parameters having an influence on the attainment of sterility have been identified, tested and documented; in short the thermal process has been validated. For each type of retort the validation protocol is different. These protocols, when needed, are available from the retort suppliers, or from specialised institutes involved in food processing. 3. Validation procedure: Without covering all of the items in the FDA guidelines and questionnaire, there are two fundamental tests that should be carried out by all retort users. 1. Temperature distribution study: The purpose is to obtain evidence and document the actual temperature distribution inside the chamber of a given retort, for a given product and a given holding temperature. The temperature distribution in a retort is qualified by two parameters: – The gap between the warmest and the coldest point. – The location of the coldest point.

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The temperature of the coldest point is the key figure from which the holding time will be established in defining the required F 0 value for product sterility. 2. Heat penetration study: Assuming that the F 0 value required for sterilising a given product has been determined, subsequent to conducting the temperature distribution experiments, the heat penetration study can be carried out. At the end of a sterilising cycle, all cans of the batch, whatever their location inside the chamber of the retort, are required to have received an actual F 0 value at least equal or greater than the F 0 value required for ensuring the sterility of the product. In reality, the F0 value delivered to each can depends on the temperature distribution. The purpose of the heat penetration study is to validate that the F0 value delivered at the coldest point of the retort is sufficient. If not, the holding time will have to be increased in order to also increase the F 0 value achieved at the coldest point. All new retorts are delivered with several threaded ports located on the side of the chamber, specially dedicated for temperature distribution and heat penetration studies. These ports allow the passage through the wall of the chamber of the thermocouples – or temperature probes – placed inside the chamber for the temperature distribution tests or plugged into the cans for the heat penetration tests. Several suppliers are offering multi-channel data loggers able to measure and record 12–24 or more temperatures simultaneously, to calculate the corresponding F0 values and to print all data at required time intervals. One of the most popular suppliers of data loggers for the canning industry is ELLAB Company in Denmark. See Figure 8.14 for examples of products and packages that are sterilised nowadays.

9

Management of thermal process

Nick May

9.1 ROLE OF THE THERMAL PROCESS MANAGER This chapter is an extended job description for a factory-based thermal process manager (TPM), or as he might be referred to in the United States the ‘thermal process authority’ (TPA). In UK guidelines (DH 1994), the TPM role is defined as: A designated or senior person with suitable training and experience should be the only person to assign or authorise changes to scheduled heat process. And the role also requires the following: A management structure should be set up and suitable training given such that any changes in materials, procedures or structures are notified to the thermal process manager. The Process Authority term is widely used in the United States, including in legislation, though it is not fully defined. The process authority is ‘a qualified person having expert knowledge of thermal process requirements for low-acid foods in hermetically sealed containers and having adequate facilities for making such determinations’. Therefore the definition is not very different from that of the TPM but in practice there seems to be an extra emphasis on Process Authorities being external to a food manufacturing company, so the role may often be an external overview. The qualifications required for the TPM or TPA roles are not defined, and the ‘expert knowledge’ required in the above TPA definition suggests that this is not a role that can be gained purely through qualification, e.g. being a graduate food technologist or graduate microbiologist is not sufficient for this role. The TPM/TPA needs to have an understanding of the microbiological issues affecting setting processes but also the technological issues of how products are prepared, processed and retorted. Very specialist training on heat process establishment is available from organisations like Campden BRI (Thermal Processing – A Safe Approach) or Technical. It is suggested that even these courses are not full preparation for a TPM/TPA role and that a period of mentoring under the supervision of a more experienced person is really required. In the United States there is a legal requirement that qualified/experienced persons (e.g. Better Process School trained) will be on site during production of heat preserved foods. In other parts of the world equivalent legal requirements may not exist but it is always a good practice. In truth, no one can fully understand the range of weird and wonderful behaviours of food during heating. As an individual gains more experience they will become more aware of potential risks but the TPM should always be aware of the potential for the unexpected. Play is an excellent tool for learning about product behaviour, where spare probe capacity is available during validations then it should be used to try ‘what if’ scenarios.

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Although the terms TPM/TPA imply only thermal process responsibility the role can creep over into general process safety for heat preserved foods covering container closure/integrity and cooling water quality. Ultimately it must be remembered that the thermal process manager has a key role to in the economic well-being of the business they work in. Conservatism in decisions on product safety will be reflected in the degree of cooking of products, and consequently their saleability. If a wrong decision is made, and product is underprocessed this might lead to a botulism case that will have a dramatic effect upon the business (not to mention the whole industry). Even if under-processing does not result in a safety risk it will lead to spoilage, with consequent dissatisfaction in the customers home, from the retailer and from the commercial directors within the producing company. The role of the TPM is a difficult balancing act with many facets to consider, and these are considered in the following text.

9.2

DOCUMENTATION OF THERMAL PROCESS REQUIREMENTS

It is the responsibility of the TPM to ensure that files are maintained with process establishment data justifying the thermal processes used for all products. Perhaps one of the most difficult issues for the TPM working in a plant producing a big range of product is deciding whether every product needs experimental validation or whether a recipe can be included in a group which can be represented by the slowest heating. This is an economic issue, because experimental validation can be expensive. Offset against the cost is the uncertainty of not having experimental data to back up a production process. A problem seen in US controlled markets is saving on validation costs by improper use of the process recommendation document NFPA Bulletin 26L, specifically extreme extrapolation of the data in the bulletin to situations where the authors never intended its application. For temperature distribution testing, e.g. testing the performance of the heating environment it would be nice to have temperature distribution data for all container formats produced in all retorts. However in reality this is often not done, again for economic reasons of reducing validation costs. For steam retorts the worst-case loadings will normally be the smallest container processed (Campden BRI (1979) The venting of vertical retorts for steam processing. Campden BRI Technical Memorandum 212). This makes sense because load density is increased and more dividers will be required (when used). For the different types of overpressure retort the same logic can be applied but data to justify this is scarce. With a bank of steam retorts of identical design it is reasonable to select a sample to test, e.g. one at either end of the steam supply and one in between. With the more complex overpressure retorts such assumptions are less easy to justify and there is a stronger case for testing every retort. The master files of validation of information should have temperature distribution data, cold point determination data and replicate heat penetration data to cover the plants’ entire product range. As has been explained above it may not be that every machine or product is experimentally tested but rather that the TPM has taken a decision that sufficient data is available to be confident that processes are safe. Many plants/companies have their own formats for presenting process validation data; however, those companies supplying hardware/software for process validation, e.g. Ellab in the EU and TechniCal in the United States are driving the industry toward standard report formats. Even when these companies have no part in the validation process contracting companies often have report formats similar to theirs. The drift toward standardisation is largely a good thing because it helps to

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avoid omissions of critical data and aid relatively rapid digestion of a report by interested parties, e.g. auditors. One of the biggest challenges for documentation of process validation is keeping it up to date. It is very easy for processes to evolve without major changes, eventually reaching a situation where the on-file data no longer applies. For this reason both Campden BRI and GMA recommend retesting of retort temperature distribution on a 3-year cycle. Guidelines are less clear about repeat heat penetration testing but retesting will normally be required when significant changes are made to the product. Some level of annual retesting is not uncommon. It is surprising how frequently process validation disappears in small/medium-sized companies. The TPM leaves the company, his files are lost or cannot be unscrambled and hence the information is lost. This is a scenario where using external contractors for process validation has major benefits because it is more likely that organisations like Campden BRI will still have the information on file. Although historically paper records were typical we are now reaching a point where electronic records are the more likely storage format, and so there is a need to ensure that validation reports are electronically secure. For example, Ellab’s software stores raw time temperature data in file formats that cannot be edited in line with data security standards applied in the pharmaceutical industry. Once it is decided that experimental validation of a process is required it is the responsibility of the TPM to ensure that the methods used in-house or by contractors are in line with accepted guidelines for the quantity of testing, resolution and general scientific applicability of the methods.

9.2.1 Retort surveys The concept of the retort survey largely originates in the United States, it is the process of documenting the set-up of a retort installation from boiler to retorts, and is usually carried out on an annual basis. The function of the document is to aid like-for-like maintenance and prove that the installation is not drifting away from the conditions tested during process validation. The completion of text-based surveys is laborious and dull, and it is not always possible to detect if equipment has been changed purely from a text description. Applying the maxim that a ‘picture is worth a thousand words’ digital photography has been a great step forward in recording details of retort installations with clarity. Whilst the retort survey is a concept largely applied in the United States, and US influenced canneries, UK DH guidelines do recommend that temperature distribution testing is carried out every 3 years UNLESS SIGNIFICANT CHANGES ARE MADE TO THE SERVICES (or other retort features), at which point immediate retesting should be triggered. From an auditors’ perspective it is difficult to prove that changes have not taken place without some sort of documented survey. Older mild steel retort systems gradually deteriorate as a result of rusting (particularly when in contact with chlorinated water) so surveys might include a general comment upon the condition of the machinery. It should be remembered that if equipment failure should lead to a product-recall scenario the philosophy normally applied is that product will be recalled back to the last good check. If no recorded checks of equipment performance are made that means everything.

9.2.2 Changing ingredients and preparation methods Within HACCP studies for heat preserved foods a critical control point is often identified at the retort, referred to as ‘sterilisation’. However, in order for the time and temperature conditions applied at the retort to work there may be several preparation stages earlier in production that are

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equally (if not more) important. There are product preparation stages that affect heat penetration into the product through effects upon product viscosity, the temperature of product as it reaches the retort or size particle. Though the primary controllers are viscosity, particle size and initial temperature, these are in turn affected by factors controlled in the plant such as:

r r r r r r

Formulation control Thawing of frozen raw materials Rehydration Control of particle size Blanching Handling and conveying

Therefore any of these factors (and more) might be critical control points for product heating. It is the responsibility of those who establish the retort process to understand how these factors affect product heating and make full allowance for them in designing the heat process. It is impossible to generalise about how different combinations of preparation conditions and ingredients interact within the preparation of a heat preserved food to affect heating rates. The only advice possible is to recommend that new scenarios be experimentally evaluated. For example, if it is planned that an ingredient is to be changed in a recipe there should be heat penetration data to prove that the effect will not impact on process safety. The same is true with equipment. For example, if a 50-L steam jacketed pan used for make-up of a starch base sauce is to be replaced with a 200-L vessel then it should be proved that the viscosity of the sauce (and therefore heat penetration) are unaffected by the change. Where ingredients are changed and subsequent heat penetration tests carried out, it is a good idea to database the results so that if the same ingredient change arises in future retesting may be avoided. It is not unheard of for auditors/inspectors visiting canning plants to raise the failure to control a critical factor as a major issue. It is a brave auditor who would do this unless they have specific knowledge of the process because critical factors for one product/process may be largely irrelevant for another. The decision on what is or is not a critical factor may be largely based upon the experience of the TPM who may not have documented evidence to prove the decision. Experimental approaches such as that outlined in Campden BRI R&D report 102 may be useful in answering any queries.

9.3 MAINTAINING AND CALIBRATION OF KEY INSTRUMENTATION The TPM may need to design a system for calibration of instrumentation critical for the correct application of thermal processes. The regime will require selection of appropriate methods for calibration and appropriate intervals.

9.3.1 Temperature calibration The primary instrument of concern on each retort will be the master temperature indicator (MTI) (either a MIG or a high specification PRT) as it is used as the ultimate reference for retort temperatures. In the United Kingdom a 6-month calibration interval is recommended, in the United States 12 months is the minimum.

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Calibration method selection is complex and depends on whether the MTI can be removed from the retort for calibration or must be calibrated in place. A strategy that allows removal of the whole instrument (display and sensor) for calibration is probably easier than a system that requires a calibration standard to be located in close proximity to the MTI probe in place on a retort and providing a stable calibration environment (it should be noted here that a retort controller may be perfectly adequate for processing batches but too unstable for good instrument calibration). Record checkers will be working to a specified maximum difference between readings from the MTI and the chart records. Procedures should be in place for what happens when this maximum is exceeded. It would not be sensible to assume that the MTI is always the correct instrument. A less obvious calibration requirement for temperature calibration is that required for process validation equipment, e.g. thermocouples or cableless loggers such as Datatrace or TrackSense. The thermal process manager should ensure that equipment used for process validation is calibrated to national standards whether it is in-house equipment or that used by a contractor.

9.3.2

Timers

As processing timing is increasingly being managed by computerised controllers rather than operators using a wall clock, calibration of those timers is becoming increasingly important. Although it is not a particularly friendly method, comparison with national time signals is recommended.

9.3.3

Maintenance

Instruments can become damaged or difficult to read with age. It is the responsibility of the TPM to ensure that defective instrumentation is identified and replaced. Readability can also be lost if additional pipework or other instrumentation is installed too close to the critical instrument, and regular reviews of the installation (e.g. retort surveys) should pick this up. Where the accurate function of a temperature instrument requires a bleed system then correct function of that bleed should be reviewed.

9.4 TRAINING OF KEY STAFF In an age where staff retention in the food industry is becoming increasingly difficult, good training systems are required to ensure that staff have the necessary background knowledge to make good technical decisions despite not necessarily having years of experience. It might be added here that a good TPM will not be solely an office-based creature but will spend time in the manufacturing environment where they can pick up those situations where products and processes deviate away from specified schedules. Key roles that the TPM may play a part in designing and implementing training for are: 1. Maintenance 2. Retort operators 3. Record reviewers However, this does not exclude the TPM from input into training other staff, e.g. in the filling area, where some critical heat process factors will be controlled. For specialist roles some degree of succession planning is appropriate along with arrangements for adequate cover during foreseen and unforeseen staff absences.

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9.5

215

REVIEW OF PRODUCTION RECORDS

The TPM or a designate will be responsible for the day-to-day review of critical records from production, particularly the chart records and retort operators log sheets. This review process is a legal requirement in some countries. The review process is normally completed with a signature indicating review and approval of the records. The collated records are commonly checked within 24 hours of a product being manufactured. The inspection is primarily to ensure compliance of production to the documented process schedules for each product. However a large part of the role is also ensuring completeness, e.g. that no information is missing (either a complete record or single data entries from a record sheet). Systems are required to ensure that all appropriate records are recovered from production. Once records are inspected each will be checked to ensure that that the record is signed off, legible and permanent. In smaller companies packaging integrity records, e.g. seam check records may also be fully under the record review role of the TPM. The review process needs to confirm that the correct heat process has been applied to the identified product. For paper chart records perhaps the most simple way to review the records is to prepare a minimum time/temperature profile on a clear acetate sheet, that can be superimposed over the actual chart record for quick comparison. As companies move away from paper chart records towards electronic records, the ease of review should be kept in mind when considering software design. For example if printed chart records are to be retained it is useful if the chart scale can be fixed to make comparison easier. Where an issue with production records is identified this normally results in a non-conformance being raised. This may be recorded in a deviation log. Another role of the TPM is to ensure the reconciliation of the volume of processed product with that documented in production records of the heat process. For batch retorting operations there are various methods for this. Some plants use coloured markers to indicate the process status (processed/ unprocessed) of a crate of product. Reconciliation is achieved by counting the number of processed markers removed from crates as they pass to secondary packaging operation. This number can be compared with the number of baskets prepared or processed in retort records. A more complex system is to use autoclave (colour change) tape marked with a unique code corresponding to each filled crate. Reconciliation can be achieved by cross-checking the codes of crates prepared with the codes on the tape, which is removed from the crate after the heat process. Sometimes this system is combined with the collection of sample cans, e.g. for taste panels, QC or incubation as the coded tape is attached to a specific can that is retained. For continuous processes, reconciliation is more difficult. Suffice to say that the TPM should ‘walk the job’ and regularly review a line to ensure that there are no obvious means of process bypass, e.g. cans jumping from one runway and falling onto one another.

9.6 MANAGING NON-CONFORMANCE (PROCESS DEVIATIONS) The key to dealing successfully with process deviations must be preparation. This may seem back to front but at a time when difficult decisions must be made quickly, having thought through and planned for each scenario will be invaluable in good decision making.

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Table 9.1

Summary of modelling capabilities.

Parameter

Can effect be predicted with current software based upon f h and j analysis

Initial temperature Retort temperature Process hold time Come up time Changes in product recipe (e.g. viscosity) Changes in particle sizes Change in container size Changes in retort type Agitation rate

Yes Yes Yes Yes No No Container size conversion are available for the Ball method No (some potential, with care) No

For example, when dealing with a rotary full water immersion retort system the things that might go wrong in a process are:

r r r r r

A short process time; A low process temperature; The wrong pressure conditions; Slow rotational speed; and Low water level.

Process validation data can be prepared under each of these conditions so that if, or when, they occur in production a quick and informed decision can be made on the likely effect on product. The choice is simple economics and is the cost of the extra heat process validation work justified in saving on the cost of scrapping batches subject to deviations for which no data is available. Historically, product which is suspected to be underprocessed (time/temperature) might have been dealt with by taking samples for incubation (though statistically it is difficult to economically take sample sizes sufficient to give real assurance). Now the use of heat transfer models such as Campden BRI, CTemp program or FMC’s numerical are a better option, because with the right input data they can accurately estimate the real Fo value achieved by the batch undergoing a deviation. With this estimated Fo value for the deviation scenario available a more confident decision on product release or destruction can be made. As a final note of caution, it should be remembered that process-modelling tools are limited by the validity of the input data. If the heat-transfer rates in the sample data do not represent the slowest that can occur then the model results will not be safe. Table 9.1 summarizes those parameters that can be modelled successfully using current techniques and those that cannot. Particular care should be taken with prediction upon broken heat products because modelling techniques assume breaks are time dependent, though in reality they can be temperature or even shear dependent. This could make predictions under changed process conditions inaccurate. The use of heat transfer modelling is recommended only for simple heating scenarios, where broken heating occurs and there is any doubt about the mechanism being time or temperature triggered, such modelling is best avoided. Legal authorities and customers want evidence to show that process deviations are dealt with systematically, promptly and that records are kept of the actions taken. These records may take the form of a deviation log which might include: 1. The nature of the deviation; 2. The amount of product affected (including samples removed);

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3. The current location of the stock; 4. The ultimate decision taken on the stock; 5. Who made the decision and why (regulators will want proof that the decision has been taken by a competent person); and 6. The safe disposal of scrapped product. It would be remiss of a TPM not to use records of process deviations as a tool for continuous improvement, specifically looking for repeat offenders, e.g. a machine that regularly results in deviations.

9.7 CONCLUSION This chapter has tried to summarise the role of the TPM within a food-manufacturing company processing heat preserved foods. This brief discussion has highlighted what a responsible and varied role the TPM has. Although commonly a recognised role within heat preserved foods companies, it is not a role that is recognised outside of that environment, there in no institute of TPMs, perhaps this role is best filled by the Institute of Thermal Process Specialists.

REFERENCES Campden BRI (1979) The venting of vertical retorts for steam processing. Technical Mamorandum 212. Campden BRI, Chipping Campden, Gloucestershire UK. Campden BRI (1999) Heat processed foods: The use of the Taguchi method for identification of critical factors for product heating. R&D Report 102. Campden BRI Chipping Campden, Gloucestershire UK. Department of Health (UK)(1994) Guidelines for the safe production of heat preserved foods. TSO London.

10

Principal causes of spoilage in canned fish products

Joy Gaze

10.1

THE QUALITY OF RAW MATERIALS

In the manufacture of canned fish products, as with most foods, the microbiological content of the raw material is crucial for the effective preservation or stability of the end product. After harvesting, microbial growth on and in the raw fish must be minimised. This is generally achieved by the use of chilled storage, which will minimise the opportunity for growth of the contaminating organisms. Heat processes are designated times and temperatures that have been set and usually validated to be able to inactivate a particular number of defined microorganisms. If, during the preparation stages of manufacture, microbial growth does occur, it can result in higher than expected numbers of organisms present in/on the fish and can challenge the adequacy of the scheduled heat process, resulting in viable organisms remaining after the application of the process (Sofos, 1994). Subsequently these surviving organisms may grow after the process and cause spoilage during storage in the warehouse, on retailers’ shelving or indeed with the consumer. The fish species, global location, methods used to harvest and subsequent handling will all influence the microbial type and number present on the raw fish. The extent of microbial contamination and the fish environment (e.g. temperature, fat content and presence of salt – either fresh or sea water) determine the extent of microbial spoilage. Gram-negative aerobic rods, such as Pseudomonas spp., Acinetobacter and Moraxella initially oxidise the amino acids; this is followed by putrefaction to produce different types of volatile compounds such as trimethylamine and histamine (responsible for causing scombroid poisoning after consumption, particularly in fishes such as tuna). Poor-quality fish that has supported the growth of microorganisms can be characterised by the presence of slime, discoloration of the gills and eyes and loss of flesh texture (Valdimarsson et al., 2004). The preparation of raw materials for canning and the handling issues associated with crosscontamination from gut microflora from fresh fish to the finished product have to be carefully considered. Thorough planning for the throughput of cans in the manufacturing environment is very important to avoid contact between the beginning and the end of manufacture. Typical examples of microorganisms that may cause spoilage of fish include yeasts, moulds, bacterial cells and spores. Bawa and Jayathilakan (2002) listed some of the popular canned fish products consumed around the world. These included sardines, mackerel, tuna, salmon, carp, roach and perch. These fish may be packed whole, or as steaks, chunks or pieces. Each product may be heat processed in its own juices, or in oil, brine or tomato sauce, or may be solid packed. Shehata et al. (2004) investigated the effect of canning common carp fish in olive oil and cotton seed oil, with nisin, lemon juice and salt. They concluded that using lemon juice at pH 4 in order to reduce the time of heat processing was effective without experiencing spoilage during storage.

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One specific issue that can occur during the preparation of canned fish products and give rise to spoilage is incorrect headspace in the cans, which could be caused by product overfill. For example, each fish product will have a set weight of fish and a set weight of liquid. If, however, in error one of these is greater than expected, the can will then be overfilled. The consequence of incorrect headspace is the subsequent change in the heating characteristics of the product, which could result in inadequate heat penetration and subsequent under-processing of the canned fish. An automatic fill weight detection system would overcome this issue by detecting and alerting the operatives to an issue at a very early stage.

10.2 HYGIENE AND GOOD MANUFACTURING PRACTICE In the manufacture of canned fish, there are a number of critical factors that may affect the risks of spoilage, such as follows:

r r r r r r r r r r

The size and the shape of the can (to ensure good heat penetration to all areas of the can); The material of the can construction (aluminium is an example of a softer metal, which is prone to denting); The can end seals, particularly double seams (vulnerable to leakage immediately after formation and during total water immersion for cooling after the heat process, or indeed if handled whilst still wet from cooling); Easy opening features such as ring pull cans (this may provide an area of weakness where organisms may gain entry to the can); Also roll back lid formations (occasionally this mechanism can fail due to its lack of robustness to physical contact/impact with other cans or runways, etc.); Poor design of can runways (cans allowed to crash together and delay continuous movement throughout the manufacturing site, or irregular cleaning schedules allowing the build up of debris on the runways near the can seam areas); Poor cooling, i.e. taking too long to reduce the internal temperature of the product, which could allow surviving microorganisms to grow; Poor water quality for cooling cans after heating (chlorine content too low, allowing microbial levels to increase in the water over the production day); such water could leak into hot cans and result in contamination; Cooling water temperature too high (inadequately controlled water temperature could allow microbial numbers to increase in the cooling water, particularly thermophilic sporeformers); and If product is palletised before it is sufficiently cooled, then the mass of cans may retain heat and indeed act as an incubator for the cans.

10.3 POTENTIAL SPOILAGE ISSUES ASSOCIATED WITH CANNED FISH PRODUCTS It is possible that spoilage organisms will be associated with the following issues:

r

Poor-quality raw material that could yield an array of different spoilage organisms; for example, thermophilic spoilage often occurs in products that have added ingredients such as seasoning, which are excessively loaded with these bacterial spores. The typical example occurs if finished

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products are palletised at too high a temperature, e.g. above 40◦ C, and this is maintained as the product slowly cools. These conditions will allow thermophiles to grow and potentially spoil the product. Faster cooling of the cans will help prevent this problem. However, caution must be given to any cans which may be shipped to hotter climates where the ambient temperature is considerably higher. Poor hygiene, i.e. organisms intermittently seeded to food product from a contamination point within the processing facility. Post-process handling of cans, e.g. ingress of organisms whilst seams are not tight. The range of organisms could be very diverse; the product contents can be examined for visual signs of spoilage, i.e. odours, colour, structure. Damage to cans such as pinholes or dents, due to poor runway design, could allow contamination to enter the cans at any stage, with potential spoilage occurring at the factory, during storage, during transit and during shelf-life. Survival of organisms after the heat process, and growth during cooling due to the fish product core temperature not reaching the target cooling temperature. The transfer of surviving organisms from clumps/chunks of fish in the product, which have not received sufficient heat treatment and subsequently into the liquid (e.g. brine), allowing growth post-process. The establishment of the slowest heating point/cooling point, which can vary depending on the shape of the can. For example, if incorrectly measured, the scheduled process could be too low; which may relate to the orientation of the product, the proportion of liquid to solid/particulates and consequently the survival of organisms. The heat resistance characteristics of any contaminating organisms may vary in different product formulations; for example, the heat resistance is likely to be very different in fish packed in oil rather than fish packed in brine and this will influence whether they are likely to survive. For example, these organisms will survive for longer periods than expected due to fat protection as they become encapsulated in the oil.

10.4 TYPICAL CAUSES OF SPOILAGE IN CANNED FISH PRODUCTS Typical microbial groups that have been isolated from canned fish and are capable of causing spoilage include anaerobes, facultative organisms, spores, thermophilic organisms and micrococci. Hersom and Hulland (1980) described a study, which over a four-year period sampled 6360 cans of fish, including fish in tomato sauce, fish in oil, fish in natural juice and fish in other liquids. A proportion from each fish product type (2.3 to 5%) contained Micrococcus, Streptococcus and other Gram-positive cocci. There were no signs of distortion to the containers and the contents were not obviously spoilt. The Bacillus group causes spoilage of canned fish products, not necessarily producing gas but characterised by off-odours or changes in the colour and texture of the fish flesh. In particular Bacillus cereus, Bacillus subtilis, Bacillus coagulans and Bacillus circulans have been associated with products such as salmon, crab and shrimp. These may be more likely to dominate in minimally processed products. These sporeformers become more apparent following incubation testing at 30◦ C. The anaerobic sporeformers that may be associated with fish are present in the sediments of lakes or the seabed and are likely to become a source of contamination in the fish intestines.

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The most common types of anaerobes that could cause gaseous spoilage in canned fish are the mesophilic clostridia. This spoilage is usually characterised by the visible disintegration of the flesh and subsequent off-odour. The gaseous spoilage can be minimised in products with reduced pH; however, the visible signs of spoilage usually persist. The optimum temperature for most mesophiles is 37◦ C; however, the range for growth can extend below 20 and above 50◦ C. The key proteolytic and often putrefactive clostridia relevant to fish spoilage are Clostridium sporogenes and Clostridium bifermentans. For those fish products that may be combined with carbohydrates, the saccharolytic group, include Clostridium butyricum, Clostridium pasteurianum and Clostridium perfringens. The most common cause of putrefactive spoilage in canned fish is Clostridium sporogenes (Sofos, 1994). Canned fish spoilage can be due to chemical and enzymatic reactions as well as from microbiological growth. For example, the production of hydrogen swells or the corrosion of cans is due to chemical reactions. In addition, the product may become liquefied and discoloured due to enzymatic reactions. Interestingly, the Fishery Industrial Technology Center, University of Alaska and the Canadian Food Inspection Agency have researched the detection of the presence of ethanol as a spoilage indicator. They canned wild Alaska whole pink salmon previously stored for 2 days at 14◦ C and were able to find a correlation between the ethanol concentration and sensory evaluation (Chantarachoti et al., 2007).

10.5 TYPES OF SPOILAGE 10.5.1

Pre-process issues

Whilst there are the obvious spoilage issues related to the inadequate storage of raw materials pre-process, there are also two key issues that are specific to the manufacture of canned fish:

Histamine poisoning A specific form of food poisoning can be associated with certain types of canned scombroid fish. Histamine is produced in fish by the decarboxylation of histidine. This reaction is enhanced by the enzyme histidine decarboxylase, which is present in many bacteria. Many fish species, particularly tuna and mackerel (scombroid varieties), contain large amounts of free histidine, which is then available for decarboxylation. Consequently, the combination of high levels of these bacteria because of poor hygienic practices and inadequate storage conditions can allow high levels of histidine decarboxylase activity and subsequent presence of histamine in canned fish. This can be minimised by the use of good-quality raw materials, hygienic handling and chilled storage of the fish prior to canning.

Staphylococcal food poisoning If Staphylococcus aureus was present in fish prior to processing and it was held at conditions suitable for growth, for example, at ambient/room temperature for greater than 3 hours, the organism could grow to sufficiently high concentrations to produce enterotoxins in the fish product (growth and enterotoxin production can occur over the temperature range 10–45◦ C; Doyle, 1989). The organism itself may not remain viable before processing as it is sensitive to heat and chemicals and indeed is unlikely to survive a typical Fo10 fish sterilisation process. The enterotoxins which are produced by this organism are, however, very heat stable and could remain throughout the heat processing and during shelf-life of the canned fish (Hobbs and Roberts, 1993).

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10.5.2

Underprocessing

The reliability of the scheduled manufacturing heat process depends on the appropriate choice of hold time and temperature, particularly in relation to the expected effects on the target organism. All of the following actions are very important:

r r r

The application of the heat to achieve the selected temperature and time combination; The control of the temperature for the required time; and The recording of these data to prove that the minimum process was achieved.

If there is a failure to achieve the scheduled heat process, there will be a risk of the survival of food poisoning and spoilage organisms, which are likely to be dominated by the presence of bacterial spores as opposed to vegetative bacteria (Department of Health, 1994). Spoilt swollen fish cans are usually associated with gas production from contaminating microorganisms, often anaerobic organisms, which have survived the heat process.

10.5.3

Post-process spoilage issues

Post-process spoilage accounts for 60–80% of the spoilage of canned foods (Ababouch, 2003). Key factors are highlighted below that are relevant to and could be the cause of post-process microbial spoilage.

r

r

r r

Poor cooling after the heat process: – so that the cooling period is extensive; – the final cooling temperature is not low enough; and – the cans are transferred to a storage facility where the temperature is sufficiently high to allow germination and growth of the spoilage organisms; Leakage into the cans: – through wet can seams, poor-quality seams with faults; – through damaged containers with pinholes; – issues with the side seam (i.e. tightness), over flanging, defective double seam or damage to the can during transport within the factory environment can all affect the can integrity; – the manner in which cans are handled can increase the risk of problems, e.g. cans crashing together or against another solid object can damage the seams; – if the can integrity is challenged, microorganisms could leak into the cans, may grow in the product and cause issues; and – there would be potential for a range of microorganisms to leak into the cans, including vegetative bacteria, spores, yeasts and moulds; Handling of wet containers: – allows for the potential for microbial leakage into the cans; and – it is very important that cans are dry before any handling occurs (Thorpe and Everton, 1968); Poor-quality cooling water: – presence of bacteria in the cooling water; this can be avoided by adding chlorine to a level of 2–5 ppm.

One extreme example of post-process contamination of fish occurred in Alaska in 1978 where there was a Clostridium botulinum outbreak associated with canned salmon (Bell and Kyriakides, 2000). This product was consumed by four elderly people from two homes in the United Kingdom during a meal together and within 11 hours, all four had developed nausea, vomiting, dry mouth

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and blurred vision. Two were admitted to hospital and antitoxin to botulism was administered; however, the administering of the antitoxin was considerably delayed for the other two patients, who subsequently died. C. botulinum type E can be found in raw fish but the canning process would normally destroy both the organism and its toxin. In this case, C. botulinum type E toxin was detected in the sera of all four patients and in washings of the empty salmon can (as were spores). Whilst the batch of over 14,000 cans of salmon from Alaska was recalled and microbiologically assessed, no further contamination was found. This problem was associated with one can, which had a fault at the rim, with a hole through which C. botulinum probably entered. It is understood that dirty coats worn by cannery operatives were draped over the wet processed cans after they had been cooled. Therefore, it is believed that the organism was leaked into the container at this post-process stage. It is unclear whether the salmon was spoilt or had any off odours, as often these food poisoning organisms do not visually spoil the products.

10.6 MICROBIOLOGICAL EXAMINATION OF SUSPECT SPOILT CANS When investigating spoilage incidents, it is expected that there will be a full microbiological evaluation to obtain microbiological isolates, which will be indicative of the type of contamination. Initial screening of samples could take the form of a sterility test to fully screen for any viable organisms. If microbial isolates were detected then further identification would proceed to species level. It is typical to pre-incubate cans at 30◦ C for up to 14 days to allow the resuscitation of any injured organisms. This may be followed by transferring samples of the product into suitable media and incubating at 25, 37 and 55◦ C. Full details of incubation testing regimes can be found in Campden BRI Guideline 34 (Bratt, 2001). In addition, there can be considerable difficulty with recovering organisms from oily environments such as mackerel in oil. It is important that the organisms are fully removed from the encapsulated state, otherwise they may be viable but will not grow and consequently a lower concentration will be recorded. One technique used by Gaze (1985) involved the use of Tween 80 to emulsify the oil with diluent and filtration to remove the organisms from the solution.

10.7 MICROBIOLOGICAL INVESTIGATIONS – DECISION CRITERIA Table 10.1 contains microbiological questions which could form part of a decision tree to assist with determining the type of spoilage:

10.8 CONCLUSION In conclusion there are a number of species of bacteria, yeasts and moulds that can cause spoilage issues with fish products preserved in cans. The basis for these microbiological problems relate to raw material quality, pre-process storage conditions, preparation procedures, can seam quality, filling capabilities, can handling procedures and storage throughout product shelf-life. Good manufacturing practices and thorough HACCP should ensure that these issues are minimised as is demonstrated by the sound record established for the fish canning industry.

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Table 10.1 fish product.

Evaluation of the microbiological content to determine the type of spoilage present in the canned

Questions on the microbiological observations:

What would the observation be?

Pure culture or mixed with many different types of organisms?

Pure cultures tend to indicate little competition from other microorganisms, whereas mixed flora is more indicative of leakage in the can post-process, which can include a wide range of microorganisms.

One dominant type?

Indicative of survival of the heat process particularly if this is a sporeformer.

Yeasts, bacteria or moulds?

If all three types of microorganisms are present, this is probably associated with leakage in the can post-process. Yeasts, moulds and vegetative bacteria typically do not survive these types of heat treatments.

Sporeformers present?

Bacterial spores can survive the heat process; however, the treatment should have been designed to destroy them. May be indicative of underprocessing, particularly if a large proportion of the batch is spoilt.

REFERENCES Ababouch, L. (2003) HACCP in the fish canning industry. In Safety and Quality Issues in Fish Processing, edited by Bremner, H.A., pp. 31–53. Woodhead Publishing Limited, Cambridge, UK. Bawa, A.S. and Jayathilakan, K. (2002) Fresh water fish processing – a review. Indian Food Industry, 21(5), 34–40. Bell, C. and Kyriakides, A. (2000) Clostridium botulinum: A Practical Approach to the Organism and Its Control in Foods. Blackie Academic & Professional, London, UK. Bratt, L. (2001) Guidelines on the Incubation Testing of Ambient Shelf Stable Heat Preserved Foods. Campden & Chorleywood Food Research Association Guideline 34. Chantarachoti, J., Oliveira, A.C.M., Himelbloom, B.H., Crapo, C.A. and McLachlan, D.G. (2007) Alaska pink salmon (Oncorhynchus gorbuscha) spoilage and ethanol incidence in the canned product. Journal of Agricultural and Food Chemistry, 55, 2517–2525. Department of Health, UK (1994) Guidelines for the Safe Production of Heat Preserved Foods. HMSO Publications, London, UK. Doyle, M.P. (1989) Foodborne Bacterial Pathogens. Marcel Dekker, Inc, New York. Gaze, J.E. (1985) The effect of oil on the heat resistance of Staphylococcus aureus. Food Microbiology, 4, 277–285. Hersom, A.C. and Hulland, E.D. (1980) Canned Foods: Thermal Processing and Microbiology. Churchill Livingstone, London, UK. Hobbs, B.C. and Roberts, D. (1993) Food Poisoning and Food Hygiene. Arnold, London, UK. Shehata, M.I., Abu-el-matti, S.M., Ez-el-rigali, A. and Salama, M.I. (2004) Effect of storage on the chemical composition and bacteriological status of canned common carp (Cyprinus carpio L.). Egyptian Journal of Agricultural Research, 82, 4, 1917–1934. Sofos, J.N. (1994) Microbial growth and its control in meat, poultry and fish. In Advances in Meat Research, edited by Pearson, A.M. and Dutson, T.R., Vol. 9, p. 359. Chapman Hall, New York. Thorpe, R.H. and Everton, J.R. (1968) Post Process Sanitation in Canneries, Campden Food & Drink Research Association Technical Manual No. 1. Valdimarsson, G., Cormier, R. and Ababouch, L. (2004) Fish safety and quality from the perspective of globalisation. Journal of Aquatic Food Production and Technology, 13, 103–116.

11

Commercial sterility and the validation of thermal processes

Geoff Shaw

11.1 INTRODUCTION The main objective of thermally processing a canned food product is to ensure that the end product that is delivered to the consumer is a safe one and poses no risk to the health of the consumer. This must therefore be the main consideration for the thermal process expert when establishing a new process for a product and should be at the forefront of all decisions made during the validation. The practice of applying a heat process to a food product that has been hermetically sealed into a container is not a new one having been utilised for nearly 200 years since the development of the basic principles by Nicholas Appert (Appert, 1810). Since then technologies have developed in both the packaging of the food product and the application of the heat process and in many cases the focal point of the developments will have been enhanced safety. Whilst producing a safe product must be the main concern of the thermal process expert when establishing a new process, it is also important that the quality of the end product be considered within the validation process to ensure that the safe product produced is one that is organoleptically acceptable to the consumer and so commercially viable. In order to ensure that the thermal process that is developed within a validation guarantees a safe end product it is critical that the thermal process expert considers the worst case for all aspects of the process of producing the end product. These can be broadly divided into two main areas: what is happening outside the can, or the conditions to which the container is exposed, and what is happening within the can. Once these are fully understood, a process can be established and a scheduled process duly recommended. This chapter will highlight the methods available to the thermal process expert in order to understand these two areas and will consider the equipment and tools that are available to allow an accurate and thus safe validation to be achieved. Whilst the main focus of this chapter is on the procedures required to produce a sterilised fish product, many of the practices outlined and discussed will be common to most in-pack processed products. The deliverable of a thermal process is a scheduled thermal process for a product and this chapter will aim to allow the reader to achieve this. The main area of interest to a thermal process expert when carrying out a validation is naturally temperature and the requirement to accurately measure it and this is the case for both of the two areas mentioned previously. The validation requires the accurate measurement of the temperature that is being achieved within a retort system and in turn the temperature experienced within the product itself. This latter measurement is particularly critical as it is from these data that interpolation of the microbial kill that is being achieved in a product will be carried out. In-depth discussion of the microbiology behind the sterilisation process is beyond the remit of this chapter but some consideration will be given to this subject later on in this text.

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TEMPERATURE MEASUREMENT SYSTEMS

This section will consider the equipment available to the thermal process expert and highlight the advantages and disadvantages of each type. A temperature-measuring system used for the validation of a thermal process consists of two constituent parts: a temperature sensor and a data-logging component. The sensor type that may be connected to a datalogger varies from device to device and as such provides flexibility for the individual application. It is important that the equipment chosen for a validation is accurate. Department of Health guidelines (Department of Health, 1994) and those produced by Campden BRI (1997) recommend an accuracy of greater than ±0.5◦ C, a tolerance that is comfortably achieved by the majority of commercially available equipment. Secondly, it is important that any equipment used for the acquisition of temperature measurement will not have a detrimental effect on the test object in terms of changing heating or cooling rates. Two types of sensor are commonly used with process evaluation equipment, thermocouples and resistance thermometers. The latter type may be sub-divided into platinum resistance thermometers (PRTs) and non-metallic thermistors. Both of these types are based on the principle of changes of electrical resistance in a sensing element due to temperature. The thermistor has a larger response to changes in temperature, and so can be smaller than the PRT and so closer to the thermocouple in terms of performance. Both of the main types of sensor, the thermocouple and the resistance thermometer have advantages and disadvantages. Of the two, the platinum resistance thermometer is regarded as the more accurate for the monitoring of a stable temperature, but the sensor size can be large compared with that of a thermocouple junction. The thermocouple provides a cheaper option than the resistance thermometers, but depending on the processing environment and their type of construction can have a shorter life span. Where the process evaluation work requires a high level of accuracy it is often preferable to use a readymade thermocouple. These are generally supplied as part of a whole system that provides all the accessories necessary for data acquisition, such as glands for enabling access to containers with minimal disruption of container preparation and product heating. The food industry has generally adopted Type T thermocouples (copper/constantan) as standard. This is despite the fact that the copper component is a relatively good conductor of heat, which could provide conduction errors, and also rapidly deteriorates when exposed to retort processing conditions. To allow the thermocouple to withstand such conditions the commercial ones are often coated with silicon rubber that is sealed at both ends. One end of the thermocouple will be connected to a jackplug that can then plug into the datalogger. The other end is typically encased in a stainless steel needle with a screw type thread that connects with the gland that has been placed in the container. The datalogger component that is used for data collection has evolved greatly over the past 15 years or so. For both the two main types of datalogger, real-time cable systems such as the Ellab EVal Flex system (see Figure 11.1) and wireless memory loggers such as the Ellab TrackSense Pro system (see Figure 11.2), advances in electronics and computer technology have allowed systems to become more compact and of greater specification. For example, the TrackSense Micro logger measures just 15 × 22 mm and can record upto 14 000 data sets at temperatures upto 140◦ C. However, whilst the small size of wireless dataloggers such as the TrackSense Micro or the Mesa Labs Datatrace Micropack III logger provides the thermal process expert with a very compact and flexible means of acquiring data, they are limited in not providing real-time data which can be of great benefit in establishing a new process in particular looking at venting phases of processes in saturated steam retorts or identifying when to commence cooling for product testing. The ‘Holy

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Fig. 11.1 Ellab EVal Flex real-time datalogging system for validation thermal processes. This system can be used for temperature, pressure and deflection measurement.

Grail’ of datalogging, a real-time wireless transmitting datalogging system is close to being achieved by the new Ellab TrackSense Pro Sky system that combines the technology used by the existing TrackSense Pro dataloggers with a transmitting component that allows data to be taken from within a process vessel without the need for cables. At the time of writing (March 2009), the Sky system has been undergoing continued tests to identify viable industrial applications, including

Fig. 11.2 Ellab TrackSense range of wireless dataloggers. These can be used for temperature, pressure and relative humidity measurement and when used with the Sky module can offer real-time data.

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sterilisation-processing applications. Tests carried out so far have demonstrated good transmission of real-time data for many food sterilisation processes with full water immersion proving to be the main barrier to successful transmission. However, it should be considered that as the Sky system is based on existing TrackSense technology, data is never lost and is stored on the datalogger’s memory until transmission can resume. Technology such as TrackSense Sky offers the potential for the work of the thermal process expert to be greatly simplified. In addition to changes in hardware, the functionality of the associated software has advanced considerably. Beyond the main functions of data recording (temperature, pressure, deflection, rotation) and lethality calculation, current datalogging software such Ellab Valsuite offer the capability to produce full validation reports with detailed analysis and supporting documentation. Other changes to software have seen greater emphasis on data security in particular with regard to data manipulation. The use of secure databases and audit trails is not at the time of writing considered by the majority of food companies but following the lead of practice in the sterilisation sector of the pharmaceutical industry increased security and data protection is a direction in which the food industry will find itself heading.

11.3

PROCESSING VESSELS

The modern food industry has many types of retort system from which to choose when deciding how best to in-container process product. The many designs encompass different heating media, including saturated steam, steam/air mixtures, raining water, water spray and full water immersion and also different styles of holding or moving the product. Some retorts hold fixed baskets either statically or rotationally during a process and other designs of retort system operate in a continuous manner with cans being carried through a heating chamber on a carrier system. The fish canning sector predominantly uses simple batch retort systems where the canned product is loaded in retort baskets and then loaded into retorts to receive a static process. The physical characteristics of the product mean that there is no benefit gained by applying agitation or rotation and so a static process suffices. For a similar reason, continuous systems such as a reel and spiral system or a hydrostatic cooker are also not used for canned fish. All of the types of heating media mentioned above are used for the thermal processing of fish, although steam/air is less common and so depending on the equipment in place at a production site the thermal process expert may potentially have to validate a product on more than one design or style of retort system and establish separate scheduled processes for each. Whilst a validation should be carried out on each different style of retort system, the general principles will be the same in each case with the primary objective being to fully understand how the retort system behaves during a process cycle and the secondary objective of understanding and documenting the conditions or settings that allowed this behaviour to be achieved.

11.4 TEMPERATURE DISTRIBUTION In order to understand how a retort system behaves during a process cycle, it is necessary for a number of measurements to be taken, the procedures for which are detailed in internationally accepted guidelines such as those produced by the Institute for Thermal Processing Specialists (IFTPS) and Campden BRI (see sources of other information). It will be observed from reading such documents that there is some variation as regards to the required experimental procedure, and

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when planning a process validation trial it is worth considering the practices generally accepted in the country to which the product will be shipped. In essence, however, the final objective is clear in all cases: to fully understand how a particular retort system functions during a process cycle and to identify any points within the system that may lead to slow heating of a product located at that position during a retort cycle.

11.5

RETORT SURVEY

A key part of any validation is to document the conditions under which the testing has been carried out, in particular with regard to the set-up of the retort or retorts that are being tested. This aspect of the validation is covered by a retort survey which documents all aspects of the configuration of a retort system at the time of testing. Areas considered within a retort survey include: (a) The retort: Dimensions, configuration of pipework, location of steam or water spreaders, air/drain/vent inlets; (b) Retort instrumentation: Make and style of devices, location, scale, calibration date; (c) Loading system: Dimension and style of baskets/racks used to hold product and of any layer pads that may be used between containers; and (d) Services: The source and specification of steam, water and air to the retort, the supply pressures and the type of valves used to control them. N.B. This list is not exclusive and further guidance can be found in the previously mentioned sources. Supporting schematic diagrams or photos can add vital information to the retort survey and greatly assist any future reviewers of the process and supporting documentation. The retort survey also allows the process validation expert to assess which of the retorts is likely to demonstrate the worst performance. For traditional saturated steam retorts this has often been considered to be the retort that is furthest from the boiler or at the end of the steam line. Whilst this may often be the case, developments in the control systems associated with modern retort installations means that this may not be necessarily so. It is therefore suggested that all retorts be tested upon first installation to confirm correct operation. On the basis of no alterations to the configuration of a retort as given in the retort survey, retesting of the system should be undertaken at regular intervals of typically 3 years (Department of Health guidelines). Should amendments or alterations be made to a system, either changes to a steam supply by changing pipework/adding new demands to the supply, or reconfiguration of container loading then retesting should be carried out sooner.

11.6 TEST LOADING The loading of a retort system for temperature distribution testing is of critical importance. The aim is to challenge the system and understand the behaviour under these conditions. It is therefore necessary to assess the container loadings that will be used within the system under consideration and identify which of these loadings will be a worst case. In the majority of cases, this will be the retort loading that has the smallest can size, the logic being that a smaller can will be more densely packed within a retort basket with more layers and less free space through which the heating media

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can circulate. It should be noted that it is common practice for a dummy load of scrap or water filled cans to be used for testing as this allows for replicate processes to be applied to a test load. Once the worst-case load has been chosen, consideration needs to be given to the number and location of the thermocouples within the load. The main objective of the test is to confirm that the retort produces even heating conditions throughout the retort load and to identify where any zones of slow heating may be. As an absolute minimum at least three points should be measured in each retort basket (Campden BRI, 1997) although it is desirable to measure at more points than this in order to get more detail and so a better understanding of how a retort is performing. Typically at least double this amount of probes should be used for each basket with around 30 probes throughout an entire retort load. The probes should be located evenly throughout a retort basket although the design of the retort system can influence exact locations. For example, raining water retorts can be slightly cooler towards the bottom of the basket, whilst steam air retorts can show cooler zones on the fan side of a basket opposite the position of the steam inlets. Certainly the bottom, middle and top of a basket should be probed with additional probes at points in between to give consideration to each side and front or back. In addition to probing the retort baskets, it is important that a further probe or datalogger is positioned next to the instrumentation sensors, in particular the master temperature instrument (MTI). In general this will be located in a vertical retort in an instrument pocket, or for a horizontal retort along the top of the machine. An exception to this can be on raining water retorts where the MTI can be positioned in the return leg of the water circulation pipework. In such cases it is difficult to locate a probe next to the instrument so generally it is acceptable to record in the water sump in the bottom of the retort. In such cases care must be taken to ensure that the probe or logger is securely attached and does not impede the loading or unloading of the retort baskets. In addition to using a datalogger to record the temperatures at the position of the instrumentation, manual readings should be taken from the displays on the control panel throughout the process with observations made as to the steam supply pressure, the operational status of other retorts or equipment on the same steam line and the timings of the start of the process phases, i.e. process start, hold start, cooling start. Where a retort is of a water spray or raining water design, consideration must also be given to verifying the rate of water flow in the water circulation system. This can be carried out either via the means of an in-line water flow gauge, or alternatively via experimental measurement at each basket position with a suitable receptacle being used to collect water for a given time interval. For a newly installed retort, a replicate run should be carried out and ideally all retorts should be tested if possible. Should this not be achievable, the retort survey should be used to identify the retort systems in which slowest heating is expected and these should be used for the tests. Temperature distribution tests should be carried out on installation of a new retort system, on changes to the supply services (steam, air, water) or on introduction of a denser loading pattern. Should no changes be made in the meantime then repeat tests should be carried out at regular intervals (3 years from Department of Health guideline [Department of Health, 1994]).

11.7 DATA ANALYSIS Once the data has been collected, it is necessary to analyse it in order to assess the performance of the retort. As with guidelines on experimental procedure there can be some variation as to what is

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deemed acceptable and as to how the data can be analysed. In general, however, there are two main criteria that need to be considered: (a) The temperature range within the retort system either at the start of the hold phase or at a defined time interval after the start of the hold phase; and (b) The temperature control within the vessel over the duration of the hold phase. Department of Health guidelines give values for these two criteria of ±0.5◦ C from the hold temperature setpoint value and within 1◦ C, respectively. A third important consideration when analysing the data is to identify any cold zones within a retort load as this information will be required for undertaking the product heat penetration tests. Should the retort performance be deemed unacceptable then it will be necessary to review firstly the retort setup in terms of the services and the loading, and secondly the retort programme that is being utilised. It may be that extending the come-up phase can allow the retort to achieve improved uniformity during the hold phase. Any changes should obviously be documented and then retested to confirm the impact on retort performance.

11.8

HEAT PENETRATION MEASUREMENT

Once the cold point within a retort has been determined, it is then necessary to consider the product. The main objective of applying a thermal process to a canned product is to deliver a microbiological kill to all pathogenic microorganisms that are present in the raw materials. For a canned fish product, the main microorganism that is targeted is Clostridium botulinum, which if able to grow inside a container can produce a potentially lethal toxin. It is therefore necessary to prove with heat penetration tests that any thermal process applied to a product is such that the product can be considered commercially sterile, that is the level of C. botulinum is such that there is no possibility of toxin production and the product is safe. However, as the heat penetration test gives only time versus temperature data, it is necessary to understand how this information can be interpolated to a level of microbiological kill in order to determine if commercial sterility has been achieved.

11.9

COMMERCIAL STERILITY AND LETHALITY

The first thing to consider is how a microorganism behaves when exposed to heat. If a constant lethal heat is applied to a microorganism, the spore population is reduced by a logarithmic order of death. By sampling different exposure times for any given temperature, it is therefore possible to extrapolate a value for the rate at which the kill is achieved at this temperature. This is known as a D-value, the formal definition of which is the time taken at a given temperature for a one log reduction or 90% reduction in the spore concentration (see Figure 11.3). The units for a D-value are minutes. By calculating D-values at a number of temperatures over the range of a typical thermal process, it is therefore possible to understand how a particular microorganism’s death rate changes with variation in temperature. Plotting the various D-values against temperature, again on a logarithmic scale, allows a further value to be extrapolated, the z-value. The formal definition of a z-value is the change in temperature required to bring about a one log or 90% change in the D-value (see Figure 11.4).

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D = x/y

Log10 numbers

y

x

Time (minutes) Fig. 11.3

A typical first-order or logarithmic survivor curve for the calculation of D-values.

The z-value is a critical piece of information in the establishment of a thermal process as it allows the thermal process expert to understand how changes in temperature impact on the microbiological kill delivered by a process and more importantly it provides the key to converting time versus temperature data into a value of kill achieved or lethality. However, before an assessment of kill can be made, it is necessary to know what level is required for a safe or commercially sterile product to be produced. Traditional thermal processes utilised saturated steam as the heating medium with systems operating above 100◦ C generally in the region of 120–130◦ C. It is therefore necessary to know how C. botulinum reacts to exposure to such temperatures. Historical microbiological (Esty and Meyer, 1922) work shows that at a temperature of 121.1◦ C (250◦ F), C. botulinum has a D-value of approximately 0.23 minute, i.e. for every 0.23 minute at 250◦ F the spore concentration is reduced by 90% or one log. Experimental work and experience (Tucker, 2008) have shown that a process that achieves 12 log reductions of C. botulinum can be considered commercially sterile. This is that if the 12D process is correctly applied to a product then the health risk to the consumer will be insignificant. The 12D process is established on the basis of an initial spore load of one spore per gram of product. Applying a 12D process reduces the probability of spore survival by 1012 or a million. Thus if cans

z = x /y D-value y

x

Temperature (°C) Fig. 11.4

A first-order curve for the calculation of z -values.

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contain one initial spore, then for every million cans produced and given a 12D process, only one can would contain a surviving spore. The minimum target process is therefore 12 log reductions and a process target (T) can be calculated. If N 1 is the initial spore concentration, N 0 the target spore concentration then for exposure to a theoretical constant process temperature of 121.1◦ C the target process for C. botulinum would be: T = D (log N1 − log N0 ) T = 0.23 (log 1 − log 10−12 ) T = 0.23 × 12 T = 2.8 minutes This value is often rounded up to 3 minutes and so the target process for a commercially safe product is the equivalent of 3 minutes at 121.1◦ C or F0 value of 3 minutes.

11.10

GENERAL METHOD

The previous section has shown that if a product was capable of instantaneous heating and cooling to and from a process temperature, it would be relatively straightforward to assess whether a target process had been achieved. As this is not the case, it is necessary therefore to find a method for converting other temperatures to an equivalent value of lethality for a given microorganism. The most common method of achieving this is to use the General Method lethality calculation (Bigelow, 1921). If L is the value of lethality achieved, T is the product temperature, T ref the reference temperature for the given microorganism and z is the z-value for the reference microorganism, the following formula can be used: L = 10[(T −Tref )/z] minutes Considering a sterilisation process where the product is recording 116◦ C therefore gives: L = 10[116−121.10/10] minutes L = 10[−0.51] minutes L = 0.309 minute The formula calculates that exposing the product to 1 minute at 116◦ C has the same effect as exposing the product to 0.309 minute at 121.1◦ C. The formula can be further utilised with a time increment. For example if a product was exposed to only 30 seconds at 116◦ C then the formula would now be: L = 0.5{10[116−121.10/10] } minutes L = 0.155 minutes So, 30 seconds at 116◦ C would deliver the same microbiological kill as 0.155 minute at 121.1◦ C. By applying the General Method to a complete product time versus temperature profile, it is therefore possible to determine the lethality that has been delivered to a product during a process and so confirm whether or not the target process has been achieved.

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The majority of software packages that are supplied with datalogging systems will include a lethality calculation option. To use these, it is important that the correct constants for T ref and z-value are utilised to ensure that a correct lethality calculation is completed.

11.11

HEAT PENETRATION EXPERIMENTAL METHODS

In order to ensure that the lethality calculation that is undertaken gives an accurate indication of the thermal process that is being delivered, it is important that the worst case or slowest heating point within a container is identified and that all heat penetration measurements for a given product are taken at this location. Cold points within containers are dependent upon the geometry of the container and the characteristics of the food product. In a traditional canned product, the cold point determination is simply a matter of taking measurements at differing heights along the central axis of the can. Products that heat by conduction, such as most fish based products, will have a cold point located at the geometric centre, although there might be a slight displacement due to the headspace or lidding materials of differing heat transfer properties. When carrying out such heat penetration validation trials, it is important that the many pitfalls associated with product temperature measurements are avoided, as incorrect measurements will result in the overestimation of process lethality and release of the unsafe product on to the market. Consequently, the main basis for heat penetration trials should always be that of a cautious approach with care taken to minimise errors and ensure that the correct or even an underestimated process is determined. There are several potential sources of error in the acquisition of product temperature data. Firstly, the system that is being used to acquire the data should be considered. Individual sensors will have slight variation so calibration is essential to provide compensation for these. For a process validation trial in a steam retort, the easiest way to carry this out is by positioning all the sensors next to the Master Temperature Indicator in a uniform steam environment. From this it is possible to generate a calibration offset or correction factor for each sensor at that temperature. The Master Temperature Indicator itself should be regularly calibrated against another instrument of a higher traceable standard. As an alternative to steam, oil baths may be used for calibration purposes, provided they are of suitable temperature uniformity and if it is proven that the retort-heating medium does not give differing sensor performance. To allow there to be confidence in the process validation measurements, it is important that the measurements are taken at the worst-case conditions which will be the coldest point within a pack and also within a retort. Such conditions must be determined experimentally for all product and pack configurations. In a properly operated retort, the variation in temperature distribution should be at the very worst 1◦ C with no significant cold points existing within the retort during the hold phase of the process. However, during the come-up and cooling phases of the process there will be greater variation with low-temperature zones present. Steam/air and water retorts may have less consistent temperature distribution, so it is important that accurate cold point determination is carried out within such systems. Once the temperature distribution trials have enabled a cold point to be determined within a retort, the containers prepared for heat penetration trials should be located at this point. It is important to define an initial temperature of the product used during heat penetration trials, as this is an issue of direct commercial interest to the manufacturer. The temperature tested should correspond to the lowest that may occur in production at the start of a retort cycle. For products with a hot fill component, it is therefore necessary to determine a level of cooling that is permissible between filling and the start of processing, and so define a maximum production delay for this phase

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of production that is defined and adhered to. Any product that fails to meet this specification for initial product temperature should be safely disposed of. By using a range of initial temperatures during the validation work, either practically or using a modelling package such as the Campden BRI CTemp software, an appropriate process duration can be specified and wastage minimised. A variation in initial product temperature is only one factor that can change within a product before processing. A delay between filling and processing can also have an effect on the heat penetration characteristics of a product that is independent of temperature. Some products can absorb surrounding sauces with a resultant thickening and reduction in heat transfer rates. To control this for such products, both time and temperature between filling and processing should be specified within the heat penetration trial conditions. Wherever possible, product formulations used for heat penetration trials should match as closely as possible those intended for production. Sometimes it will be desirable during product development to carry out a ‘look see’ trial to establish important process parameters and test quality characteristics. Such trials should match the final production formulation as much as possible, particularly with reference to those that most have an effect on temperature measurements. Ingredients that need to be considered include starches that can cause considerable variation to the equivalent process received by a product. If there is a doubt over the effect that a specific ingredient may have on the heat penetration trial, it is wise to allow for any potential variation by using additional quantities during the trials. The majority, if not all, canned fish components will include a solid component with either whole or part fish. Care needs to be taken when making up heat penetration samples to ensure that consideration is given to the largest piece size permitted within a product specification when selecting a piece of fish into which the heat penetration probe is to be inserted. For retorts that do not have layered loading and are scrambled packed, consideration must be given to the impact on product heating of the can nesting. Nesting is where cans stack together which in effect creates a single container of greater geometry which will reduce the rate of heat transfer to those cans in the centre of the stack. For products processed in retorts with such a style of basket loading the heat penetration sample will be located in the centre of a stack of possibly five cans to ensure the worst-case heat transfer conditions have been considered. Finally, one of the most important factors that can ensure the accuracy of results during heat penetration work is the good communication between those carrying out the trial and production personnel. This can help to ensure that the correct process parameters are used, particularly conditions such as time/temperature combinations, rotational speeds, retort loading patterns and container specifications which can all affect the rate of heating of the product.

11.12

FLEXIBLE PACKAGING

For traditional canned products, the only parameter that requires investigation within the thermal process evaluation is temperature. Demand by consumers for flexible packaging for some products in place of the traditional can means that it is necessary for additional measurements to be taken in the process validation experiments. During the thermal process the packaging is exposed to external pressure that builds up within the processing vessel in addition to internal pressures that can be generated by components within the product itself. These pressures provide a source of stresses to the packaging that can affect the integrity of the packaging. For the most traditional format of packaging, the metal can, the design of the container has evolved to allow for pressure differentials that are likely to be experienced at typical process temperatures in saturated steam during the process. It is therefore the ‘newer’

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packaging formats, the flexible retort pouch and the semi-rigid trays with film lids that can be affected and lose integrity during a process. To ensure that packaging integrity is maintained, it is necessary for the pressures to be controlled during a process. Flexible packaging therefore requires processing within an overpressure retort system such as those produced by STERIFLOW or Lagarde where additional air can be added and mixed with the heating medium during a process, and where an automatic control system allows the operator to use a predefined retort programme to maintain close control of pressure values during a process. The retort programme that is used for flexible packaging will have a temperature profile that ensures the target lethality will be delivered and a pressure profile that minimises stresses to the packaging and so maintains container integrity. The former will be established using the same procedures previously outlined, whilst the pressure profile will usually require the thermal process expert to measure two further parameters: pressure and deflection. The main aim of a deflection experiment is to minimise pack expansion and maintain the original geometry of a container. This is achieved by positioning a deflection transducer on the surface of the pack and recording any movement that takes place during a process. Simultaneously, the pressure within the retort is recorded and adjusted in response to movements by the deflection transducer. By these means, it is possible to establish a pressure profile that minimises pack expansion and stress. Typical equipment that would be used for such a test would be the Ellab EVal Flex real-time datalogging system. Further reading on this area of process validation can be found in ‘In-pack Processed Foods – Improving Quality’ (Seiboth and Shaw, 2008).

11.13 FUTURE DEVELOPMENTS AND INFORMATION The procedures and principles that are utilised for thermal process validations whilst longstanding are continually being reviewed and assessed. Current information on recommended guidelines and procedures can be sourced from Campden BRI or IFTPS. The equipment that is used for validation trials continues to evolve and be refined as advances in electronics and technology allow ever-smaller instruments to be produced with improving specifications of hardware and software. Information on such changes can be found on manufacturer’s websites such as www.ellab.com or www.mesalabs.com.

REFERENCES Appert, N. (1810) L’ Art de conserver pendent plusier annees toutes les substances animales et vegetale. Patris & Co., Quay Napoleon, Paris [A translation by K.G.Bitting was published by the Glass Container Association of America, Chicago and reprinted by S.A. Goldblith, M.A. Joslyn, and J.T.R. Nickerson (eds) (1961) An Introduction to Thermal Processing of Foods, AVI Publishing Co, Inc., Westport]. Bigelow, W.D. (1921) Logarithmic nature of thermal death time curves. Journal of Infectious Diseases, 29, 528–536. Campden BRI (1997) Guidelines for Establishing Heat Preserved Foods in Batch Overpressure Retort Systems. Guideline No. 17. Department of Health (1994) Guidelines for the Safe Production of Heat Preserved Foods. The Stationary Office, London. Esty, J.R. and Meyer, K.F. (1922) The heat resistance of the spores of B. botulinus and allied anaerobes. XI. Journal of Infestious Diseases, 31, 650–663. Seiboth, M.L. and Shaw, G.H. (2008) Optimising the processing of flexible containers. In Pack Processed Foods – Improving Quality, edited by Richardson, P., Chapter 7, Woodhead Publishing, Cambridge, UK.

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Tucker, G.S. (2008) History of the minimum botulinum cook for low-acid canned foods. Campden BRI R&D Report No. 260.

OTHER SOURCES OF INFORMATION Institute For Thermal Processing Specialists (IFTPS) offers a wealth of information and support for the thermal processing specialist. IFTPS 304 Stone Road West Suite 301 Guelph, ON N1G 4W4 Canada www.iftps.org Campden BRI provides training, guidelines and consultancy services for the thermal process sector. Campden BRI Station Road Chipping Campden Gloucestershire GL55 6LD UK www.campden.co.uk Ellab A/S produces a range of process validation solutions and offers consultancy services to the thermal processing sector. Ellab A/S Trollesmindealle 25 DK-3400 Hilleroed Denmark www.ellab.com Mesa Labs offers a range of datalogging solutions. Mesa Laboratories, Inc. 12100 W. 6th Avenue Lakewood, Colorado 80228 USA www.mesalabs.com Steriflow SAS and Lagarde SAS produce retort systems for the food industry. Steriflow SAS 32, rue de Cambrai 75019 Paris France www.steriflow.com Soci´et´e Lagarde Z.I. Les Plaines – N◦ 5 bis 26780 Malataverne France www.lagarde–autoclaves.com

12

The quality department in a fish cannery

Leila Radi

12.1 AVANT-PROPOS I have spent the past ten years visiting different fish canneries and while they all seemed very similar in the beginning, the people, the company’s culture, the countries and the environment made each visit a new experience. It is interesting to see how people sometimes interpret standards and work around requirements and how most workers and managers are so proud of their work and strive to always do better. We take for granted the little round or rectangular cans and we associate canned food with a quick and easy cheap meal replacement, we even associate it with pet food and never realise the amount of work, quality controls, time, care and even love that went into preparing them. Canned food, and in particular canned fish, is one of the most regulated food products in the market. The canning process in itself can be dangerous as an under-sterilised product can be fatal. Most countries have put regulations in place to assure sanitary and safe production of canned fish. In addition, there are many standards that have been developed and factories are required to be certified against them to sell their products to most markets. Working over the years with Les Bratt has been a great honour and a great pleasure for me as well as for many of my colleagues and they have asked me to include this comment in this guide. This canning process expert, who travels the world to assist and inspect factories, never loses his sense of humour as well as his gentle manners no matter what the situation is. We have all learned so much from him and look forward to his visits.

12.2 THE ORGANISATION AND THE SCOPE OF OPERATIONS OF THE QUALITY DEPARTMENT The quality department in a cannery is involved in every step of the process from receipt of materials and packaging to production, storage, release and expedition. The quality department also oversees sanitation, quality controls, HACCP (hazard analysis critical control point) implementation and the quality management aspects of standard requirements. The quality department typically consists of a team organised by the quality assurance manager. In a cannery, this team comprises a quality control supervisor, a sanitation supervisor, a retort control supervisor, a seam control supervisor and a laboratory supervisor. The quality department also administers the laboratory’s activities and organisation. The quality assurance manager is responsible for the training of his/her team and must make sure that the supervisors of critical control points (CCPs) are trained for their specific CCPs.

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The quality assurance manager, together with quality team and other factory employees from the production and administration departments, is responsible for the development of a quality system that must assure the manufacture of safe and secure food products. All members of the team are responsible for controls and their appropriate documentations as per the quality system. The quality assurance manager or designated responsible person should normally review all production records as well as all sanitation records and control records in order to evaluate the conformity of each lot produced before releasing it to the consumer market. The quality assurance manager, together with a team of trained internal auditors, must also conduct internal audits to verify the implementation of the system and identify any non-conformances for which corrective actions are required. The quality management team, together with the managers of other relevant disciplines, must meet regularly and evaluate results of the internal audits, review statistical data regarding customer complaints, review and set objectives as well as plan improvements. Today’s quality assurance manager often has the additional responsibility for the management and control of site security from the perspective of both external contamination and bioterrorism.

12.3 QUALITY ASSURANCE FOR THE MANAGEMENT OF PRE-REQUISITE MEASURES All food safety systems have similar basic requirements. The following section will review some of the most important pre-requisite measures necessary to implement a quality assurance system in the canning industry. Pre-requisite measures provide the underpinning that enables the HACCP system to function.

12.3.1

Cleaning and sanitation

Cleaning should be undertaken by trained personnel against defined procedures and schedules that define the frequency of cleaning. The procedures should specify the materials to be used, the dilutions, the equipment, the method of cleaning and the health and safety considerations including the necessary protective clothing for the cleaning operatives. It is important that the scheduling and application of cleaning does not jeopardise any ongoing manufacturing operations. Cleaning in itself is usually well understood and employees are used to removing solid and liquid waste, washing and brushing with detergent as well as rinsing with disinfectant. Most equipment in a cannery is easily reachable, from tables to conveyers, to crates and cooking trays. While most companies understand, and implement, cleaning and sanitation, pre-operative cleaning is most probably the issue that is most commonly misunderstood. Pre-operative cleaning, although necessary, may be perceived as if a person had to rewash a plate before eating after it has gone through a full wash in the dishwasher. Most canneries use caustic soda as a very effective mean of cleaning and removing grease from stainless steel equipment without any damage to the metal. The use of this chemical requires thorough rinsing to prevent chemical contamination. Chlorine is used to disinfect machinery and equipment. Many facilities use well water as well as city (potable) water to clean equipment but the final rinse must always be done with city water to minimise any risk of microbiological contamination (Dillon, 1999).

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Post-cleaning swabbing is required by most standards and is necessary to verify the efficiency of the cleaning method as well as the cleaning products (Dillon, 1999). These results are on the other hand useful only when the interpretation is well defined and well interpreted.

12.3.2

Pest control

Most quality control or management supervisors are at first puzzled when the words extermination and prevention are explained separately. Indeed they are two different but equally important aspects of pest control that need to be dealt with separately. Extermination is the treatment with poison of all pests. Such treatment is limited to areas away from production, empty packaging materials or finished products. Prevention includes all those measures put in place to provide surveillance and to measure the efficiency of the extermination process. Prevention focuses on areas where the product is manufactured or stored to prevent contamination. Prevention measures include traps and insect killers but what is also important and not always easy to communicate is the necessity to perform not only the controls but also the interpretation of the results of these preventive controls. The efficiency of a pest control programme can only be measured by the results of statistics and the corresponding corrective measures put in place in case of non-conformance. Measuring the efficiency of these corrective measures must also be implemented, documented and interpreted. Most supervisors tend to trust and assume that pest control subcontractors are knowledgeable and hold a license to perform their job. They do not automatically obtain the training records to verify the competence of the contractor’s employees. The same need for checking applies to the information on the material safety data sheets regarding the chemical products and poisons used for pest control. In addition, checking traps, changing baits internally (by factory employees) as well as documenting and interpreting statistical trends, must be done by trained employees.

12.3.3

Specifications writing

Specifications are documents that describe all aspects of a product. Detailed specifications, whether for raw materials, ingredients, packing materials or finished products, are now a requirement of any quality management system and are specifically included in food safety standards such as the British Retail Consortium (BRC) Standard or the International Food Standard (IFS). Specifications need to be developed and written by the appropriate and knowledgeable responsible employees, such as the quality assurance manager together with the production manager, to make sure all aspects of materials, ingredients and packaging of a product have been analysed and all important information identified. Raw material specifications are designed to inform suppliers, the purchasing department, goods inwards supervisors and all individuals and teams involved in the production process of what they need to know in order to realise a safe and appropriate product. Specifications must include safety and legal limits as well as special chemical, physical and organoleptic characteristics or clients requirements. Finished product specifications would ideally include a full listing of the presence or absence of generally recognised intolerant materials, and the CCPs relevant to the manufacture of the product. Specifications need to be reviewed and updated regularly by authorised employees and clients, as legal as well as market requirements might change. Specifications are official documents that must be agreed and authorised, signed and dated by all parties concerned. Finished product specifications are also used as a basis for product release after making sure that each lot of product meets the characteristics of the expected requirements (BRC, 2008).

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Documentation control

The documents in a quality management system traditionally comprise policy documents, procedures, detailed work instructions and the necessary supporting documents. In practice, quality systems require the implementation of the set of procedural documents which specify and give details on the method of doing things, the responsibilities, authorities and data recording in the manufacture of the product. It is also necessary to be able to prove the proper application of system procedures through a series of completed records. Documentation must be accessible to all relevant employees to review and must be stored and archived as necessary in a logical system. Documents should be individually identifiable by the title, document number, revision number, number of pages and issuing authority. Documentation and records, which contain all the information about the product, are important documents and must be signed by management before they may be implemented. Documents must be written, verified, reviewed and updated as necessary by the appropriate people. New versions need to be distributed as they become available and older versions retrieved and archived. Changes from version to version must be documented and justified. Personnel should be made aware of changes and be trained to implement them (IFS, 2007). Quality management systems in a fish cannery rely on many documents. Food safety systems rely initially on the HACCP plan and the associated procedures and HACCP documents. There must also be procedures that describe the production process, good manufacturing practices (GMPs) and sanitary standard operating procedures (SSOPs). In addition, today’s food standards also require management procedures, laboratory procedures, training procedures and written specifications. Records must be kept and archived as per the legislation and for as long as the life of the product.

12.3.5

Relationship with HACCP

The HACCP theory is the basis for any food safety system or quality standard whether it is the IFS, BRC or ISO 22000. Developing an HACCP plan requires that GMPs, SSOPs and good laboratory practices (GLPs) be put in place before the hazard analysis is done. The subsequent hazard analysis identifies physical, chemical and biological dangers located at each step of production as well as the probability and the severity with which they may appear. The final point of the hazard analysis is to identify CCPs and to focus on hazards that cannot be solved by the appropriate implementation of GMPs, SSOPs or GLPs (the pre-requisite measures). For each CCP and each hazard, a critical limit must be identified as well as a monitoring system, the method, the frequency, the corrective actions to be taken in case of loss of control, the people responsible for the implementation of the system and the documentation requirements. The monitoring of each CCP must be documented as well as verification that the system is being properly applied (MD Associates, 1996). Quality systems support the implementation of HACCP with management procedures that help the company organise all of its operations. Quality systems have explicit requirements that lead companies to develop and organise every aspect of daily operations and controls such as personnel training, maintenance programmes, management of complaints, evaluation of suppliers, etc. Quality systems bring many responsibilities to managers who must be involved in every aspect of the production of a safe, legal and quality product.

12.3.6

Vendor assurance, supplier review

Vendors must supply to buyers written assurance that the products they sell to them (raw materials, ingredients, packaging, etc.) comply with the relevant regulations as well as the standards. Buyers

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must have developed a specific description of the characteristics of the products they desire. These characteristics must appear as detailed specifications. Suppliers must deliver the appropriate goods and supply documented assurance that these goods meet the specifications. Raw materials should be purchased according to defined specification from approved suppliers. Consequently there should be a procedure for supplier approval and a system of monitoring and reviewing supplier performance. Supplier approval systems should be based on the potential risks associated with the material to be supplied and could include product specifications, certificates of analysis, self-audit questionnaires, third party accreditation to recognised standards and company audit.

12.3.7

Calibration

Process control, monitoring and verification must be done using appropriate control equipment. These controls are the basis for deciding on the conformity of a product. Thus, important decisions are made based on the results of these controls and the accuracy as well as the precision of the information is crucial. Calibration of equipment is one of the basic requirements of quality and safety control. As important as it is, calibration is often at first ‘misunderstood’ by many quality managers. Calibration is not just verifying that equipment works. Calibration also involves testing to see that equipment operates properly under those conditions experiences during the production process. Calibration tests must be done under such conditions and the testing should cover the operational range over which the equipment will be used in practice. The frequency of calibration is as important as calibration itself. Most equipment is calibrated on a yearly basis but the frequency should be determined based on the durability of the instrument, the usage and how critical the result might be. In the fish canning industry, fish temperature is regularly taken as well as cooking temperature. One of the most critical readings made during production is the temperature recorded during the sterilisation process as well as pressure and other temperature checks made during production. In the canning industry, calibration of seaming control equipment is as critical as retort equipment calibration as the integrity of the seam is a CCP and must be monitored at specified appropriate intervals. There should be a schedule of instruments to be calibrated including the instrument type, serial number, where deployed, working range, resolution, accuracy required, method of calibration, frequency of calibration, agency undertaking calibration, date of last calibration and date when due for recalibration.

12.3.8

Traceability

The manufacturing of products must be controlled so that each lot of finished product can be identified as well as the relationship between the finished products, the raw materials, ingredients, process details, testing details, packaging and the whereabouts of material, for every lot. All elements of the traceability system must be documented and tested regularly. This traceability exercise must be done in two directions, from the ingredients to the products (ascendant) and from the product to the ingredients (descendant). Traceability must exist throughout the production process at every step. Traceability must show that neither products nor ingredient have inadvertently been mixed even in trace amounts particularly if allergens or genetically modified organisms are used in the process. Traceability must be organised so that identification is realised during production to reduce as much as possible the possibility of human error during the coding process. Codes on containers must be legible and an authorised procedure must be available to explain all abbreviation numbers and letters and the relationship between them. Codes should include information on the product,

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the day and time of manufacture and ideally information on the production line and seaming and retorting machines used. Increasingly computer-based enterprise resource planning systems are used to track the use of materials throughout production and during subsequent despatch to customers.

12.3.9

Recall and crisis management

Recall is a subject that may be difficult to raise and to discuss with company managers and their employees. The recall must be discussed as a ‘possible’ event and corrective actions must be determined in advance in case such a situation should occur. Most managers feel threatened by the procedure in itself and spend time and energy trying to explain why it cannot and would not happen to them. Once they understand and accept that the procedure is mandatory, it is often necessary to explain the difference between a recall and a withdrawal. Recall is required when the product has already been distributed and is available to the public and a withdrawal is done when the product has not yet reached the retailer’s shelves. Recalls or withdrawals could be made in situations where there is the possibility of harm to human health or for less serious issues such as mislabelled product. Recalls must be properly authorised and monitored by a team of responsible people in the company (Crisis Management Team) who must have access to client’s information and all product documentation at all time. The recall procedure should define the composition of the crisis management team and their specific responsibilities. It would be normal to include the managing director who would have the final authority to initiate the recall together with representatives from the production, quality, sales and marketing, logistics and financial departments. The procedure should also include reference contact details for all internal personnel and external organisations that it might be necessary to contact in the event of a recall situation. The procedure should specify the manner of documentation of the recall as it progresses, the manner of investigation, the application of corrective actions and the manner of handling returned product. The main aspect of recall consists of being able to identify the whereabouts of a particular lot of merchandise in a timely manner, usually a couple of hours. In order to verify the efficiency of the recall procedure, it must be tested on a regular basis by all the people involved. Recall is a particular kind of crisis but there are other possible crises that the company’s management must be prepared for in a canning factory. Power outage, water main break and boiler damage (water, electricity and steam being used in large quantities in the canning process) and more recently security and bioterrorism are possible crises that could greatly affect the commercial viability of the company. They require the implementation of not only preventive measures but also corrective measures in the event that such a situation would occur. The recall and crisis management must be an official company document and must be authorised and dated by the company’s very senior management.

12.3.10

Management of complaints

The management of complaints has become a transparent topic as it is a part of all food safety management systems and quality managers have become used overtime to sharing this kind of information with auditors. Rather than a ‘proof of a problem’, complaints are now more often perceived as feedback and the tools for improvement as they should be. Most canneries categorise customer complaints based on the different issues of food safety or client satisfaction. Safety complaints clearly represent more serious issues while quality complaints are often linked to the sensory properties of the product or its ingredients and may be a matter of personal preference.

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Safety complaints may lead to product recall and the situation might require action by the crisis management team. On the contrary, quality concerns can lead to commercial problems. Complaints must be kept and be archived and organised by type and by danger and must be fully documented. It is important that prompt response is made to the complainant whatever the reason for complaint. All corrective and preventive measures associated with each complaint must also be documented. Information must be shared with all people involved in the production process to speed up the improvement process. Statistical data should be analysed to determine the evolution of complaints throughout the year and from one year to the next. Results must be compared to follow the evolution and to make sure that improvement is achieved. It is customary that complaints be recorded as the number of complaints per million cans sold and there should be a key performance indicator target as the upper acceptable limit to the number of complaints received.

12.3.11

Management review of the quality system

A quality management system must be regularly verified in operation through internal audits as well as site inspections. In addition, however, there should be a formal review by the management of the company of the quality system once or twice a year to ensure that it is properly implemented and is providing the necessary assurances for food safety and quality. There should be a standard agenda to which additional items may be added as required at the time. The standard agenda should include a review of the minutes of the last meeting, customer performance indicators and complaints, process performance and the incidence of non-conforming product, results from internal and external audits, review of the HACCP system, scientific developments of relevance, changes in legislation and resource requirements including training needs. Minutes of the meeting should be prepared and should include the future actions determined together with associated responsibilities and timescales wherever appropriate. The implementation of such actions should be formally monitored during subsequent management meetings.

12.4 QUALITY CONTROL 12.4.1

Inspection, testing and release of raw materials

The quality control process starts before the manufacturing of products. Before raw materials can be accepted into the factory, they must be inspected and tested according to established specifications. In a fish cannery, raw materials include fish, oil, salt and other ingredients such as vegetables and tomato paste. Upon receipt of fresh fish, the presence of ice as well as the temperature of the fish provides the first indications of the quality of the fish. An organoleptic as well as a chemical examination of the fish is often necessary and will determine whether the fish is fit for human consumption (Ababouch, 1995). Organoleptic evaluation is based on criteria defined by scientific research and needs to be performed by experienced personnel. Levels of histamine, for pelagic fish, and total volatile bases must be within the specifications. Vegetable oils must meet both legislative and clients requirements and are normally supplied with a certificate of analysis confirming that the composition complies with specification. The same general requirements apply equally to salt and all other ingredients. All laboratory tests should be carried out by persons, trained and considered competent, against the specific analytical method they are required to use. Whether the evaluation is considered as part of GMPs or is recognised as a CCP that has been identified during the HACCP process, all raw ingredients must go through the specified testing steps before release into the production process.

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The results of testing procedures should be fully documented and records retained for a defined period in excess of the shelf life of the finished products. Wherever practical, samples of raw materials may also be retained for future reference. All deliveries of raw materials should be issued with a unique lot number at the time of receipt that is used to provide traceability during subsequent manufacturing operations.

12.4.2

On-line measurement and testing

Once raw materials are accepted into the factory, their quality and safety must be maintained during storage and during transformation into finished products. Refrigerated storage of raw fish, before transformation, is crucial to fish quality and safety. In general, fish is first beheaded, eviscerated and washed in brine before being put in cans, cooked, drained and covered with liquid. Cans are then seamed, retorted, cooled, inspected and stored before final inspection, final packaging and shipment. While the fish is still raw, the speed of production is important as most canneries production areas are not temperature controlled. Online measurements and testing are done to make sure that the fish quality and safety are not compromised especially after equipment breakdown and production slowdowns. Other quality online checks may include the verification of cooking and filling temperatures, and the measurement of drained weight. Visual checks are done for the presence of foreign bodies and the presentation of the fish in the cans. The can seaming step is a recognised CCP and its verification is an essential part of a successful canning process to prevent post-sterilisation contamination. The sterilisation step is another CCP which is controlled for each retort cycle to ensure that the scheduled process time and temperature are followed for each can size, sauce or fish product. Personnel from the quality department may also be responsible for checking that all indicators used to identify processed cans from unprocessed cans (such as thermally sensitive cards) are in place.

12.4.3

Inspection, testing and release of finished products

Depending on the producing countries’ regulations, all canned seafood products might need to be officially tested by lot or production day, before being released to the market and the consumers. Whether the regulation or the client’s requirements necessitate positive release of finished products, today’s international standards have made it virtually obligatory. Positive release should be authorised by nominated members of the quality department and documented approval for release provided to the despatch department. Finished product safety and the quality of products need to be verified against internal and external (i.e. clients’) specifications. Only when all requirements are met, may the product be released for human consumption. These requirements include, but are not limited to, proof of compliance with CCP limits as well as client’s quality requirements. Importantly all records relating to the checking of double seams and the sterilisation process should be reviewed and approved by an authorised person within the company. Client’s quality requirements might include the number of fish per can, the presentation of the fish, drained weight and net weight, the colour of the sauce, the salt content, the manner of date coding and all labelling and packaging.

12.4.4

Record keeping

All information gathered in Sections 12.3.1–12.3.3 must be documented as it is collected (in real time). These records must be kept together to facilitate the final check of all legal and quality

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requirements and to provide future evidence of compliance with specification. Traceability must be available from raw materials to finished product (descendant traceability) and from finished product to raw materials (ascendant traceability). Positive release should be authorised by nominated members of the quality department and documented approval for release provided to the despatch department. All records must be archived securely and made easily accessible for at least the intended life of the product.

12.5 ESTABLISHMENT OF A QUALITY PLAN The quality plan is the template that defines the frequency and method of testing carried out during the manufacture of the product from raw material intake to despatch. It will include testing done by quality personnel both in the company laboratory and within the factory, testing carried out by production personnel, and testing subcontracted to external, ideally accredited, laboratories. The quality plan schedule should include the item to be tested, the frequency of test, the method to be used and the responsibility for carrying out the test. For each test carried out there should be a defined documented procedure against which the persons carrying out the test are trained and adjudged to be competent. For certain tests internationally recognised standards may be available and should be used wherever possible. The quality plan should be subject to periodic review to ensure that the level of testing is appropriate to ensure the required compliance with legal, safety and quality specifications. Typically the repeated incidence of a certain type of complaint may suggest the need for increased or alternative testing in a specific area. The company should also have access to a service providing updating of relevant legislative matters as changes in legislation may also require changes to the quality plan. Changes to the international food standards may also require a similar response.

12.6 STANDARD QUALITY PROCEDURES A quality system is based on procedures that must be physically accessible to all relevant employees at any time. These procedures must be in a written form, dated, authorised and up to date. Each company organises its quality procedures in its own way, but usually they are separated into the HACCP plan documents, SSOPs, GMPs, GLPs and Standard Operating Procedures (SOPs) for management. Procedures should include objectives, the detailed methods, responsibilities, controls and information about documentation. SSOPs are the procedures which specify and explain all hygiene practices such as cleaning and disinfection, pest control, water management, chemical storage and distribution. GMPs usually describe raw material reception and associated controls, manufacturing procedures and processes, CCPs or control points, maintenance procedures, storage, inspection and distribution procedures. Procedures relevant to the application of the HACCP plan are often included in the GMPs. GLPs are the procedures that describe all the laboratory tests and calibration procedures. SOPs are the procedures that relate to the management of the quality system, review of contracts, suppliers’ choices, customer satisfaction and complaints, purchases, crisis management, recall management, personnel training etc. Standard quality procedures must be reviewed and maintained as often as necessary if new equipment or new methods are introduced or at least once a year to make sure they represent

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accurately the canning process and that the management system is appropriate. Most canning establishment will have quality systems organised in similar ways as processes and equipments are very similar and since companies often use the same machines and layout (Consernor, 2008).

12.7 TRAINING OF QUALITY STAFF AGAINST PROCEDURES All the different requirements discussed in the previous chapters involve the training of staff against the procedures developed for each particular activity or process and their controls. All staff must be trained. Whether it is a refresher course, or a new topic being addressed, training events should be planned ahead according to a yearly training programme that is developed based on the needs of the company. A quality manual includes safety, process and management procedures. In principle, all employees should be trained against all relevant procedures, their competence assessed as satisfactory and that training documented and archived. The training of quality department personnel needs to be in direct relation to their responsibilities. In addition to all the general quality training, such as GMPs, SSOPs, HACCP theory, GLPs, and CCPs, supervisors must be trained in relation to the specific CCPs for which they have direct responsibilities. Separate individual records should be kept for these employees and should be easily accessible. Upon training, employees should be questioned and tested to verify their understanding of their responsibilities and their knowledge should be regularly assessed to make sure that monitoring of the safety system is done correctly. In a seafood canning facility, processes and controls are very repetitive. The process begins from fish receipt, and goes through to evisceration and preparation, cooking, filling, seaming and retorting. Special emphasis must, however, be put on the CCPs. While trained employees might feel confident that they have CCPs under control, the quality assurance manager must constantly reinforce each one’s responsibilities and duties and verify the implementation of the safety and management systems in order to prevent deviations and loss of control.

12.8 HANDLING OF NON-CONFORMING MATERIALS Non-conforming materials can appear before, during and after production, upon receipt of raw materials, ingredients or packaging materials. Non-conformities can also happen during production or storage of finished products. Non-conforming materials or products must be identified as such because they do not meet specifications and need to be isolated immediately for evaluation, while a resolution is determined, correction if possible, or held for destruction. Such non-conformities may relate to product safety, legality, quality, or deviation from client specifications. Products and materials can be, or can become, unfit for human consumption, or may differ from clients needs without being harmful. In the latter case, the materials may be reoriented for a different market with an alternative specification. If after appropriate corrective action they can be brought back within specification, the materials, packaging, ingredients or finished product can be introduced back into the production process for subsequent distribution. In a canning facility, non-conforming material or product, which is unsafe for human consumption, may arise from the raw material itself such as the case with decomposed raw fish, contaminated ingredients or packaging materials such as contaminated oil, or contaminated cans, but also from faulty processing such as improper seaming, or thermal process deviations. Non-conforming

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material or product, which does not meet quality specification but is still fit for human consumption may arise from problems such as an incorrect sauce formulation, a low net weight, an inappropriate number of fish or presentation of the fish, wrong labelling and so on.

12.9 ESTABLISHMENT AND MONITORING OF CORRECTIVE ACTIONS In Section 12.7, non-conformities were discussed and identified as products or ingredients that do not meet specifications at the time of raw material receipt, during production or as finished product. Identifying the problem and informing the supervising team of the non-conformity are only the first step in putting in place a corrective action to an inappropriate situation. Corrective actions, once determined, need to be monitored and followed up to verify whether they have been fully implemented and are effective. Corrective actions must be chosen on the basis of experience and scientific information and by assessing the risks and the dangers associated with the non-conformities. Corrective actions are usually implemented in a few steps and should be monitored from beginning to end. Different people from different departments might be involved in the implementation, with specific responsibilities, which must be executed in the appropriate order. The quality assurance manager must make sure that corrective actions are properly and effectively executed to decide whether a ‘corrected’ non-conforming product can re-enter production or distribution or be definitely excluded, reoriented or destroyed. In the seafood canning industry seaming defects cannot be made good but machines can be adjusted to meet seams specifications. All of the defective cans considered to represent a possible public health risk must be destroyed. In this same industry, retort process deviations may only be judged by processing authorities and regulations in some countries, such as the code of federal regulation of the United States of America, CFR 21 part 113, requires that the only corrective action for a process deviation is a full re-sterilisation. Corrective actions must be documented and must be a detailed summary of the entire events that have taken place from the occurrence of the non-conformity to the final evaluation and decision of the faith in the raw material, the ingredient, the packaging or the finished product. All people involved in the process must be identified on the documents as well as their role in the corrective action. These documents must be kept together and suitably archived for future reference.

12.10

LEGISLATIVE COMPLIANCE

Canned seafood is one of the most regulated food products in the world. From legislation regarding the handling of food products to regulations that monitor the canning process and seafood HACCP requirements, canning facilities must comply with the regulation of the country where they are located and producing. In addition, they must comply with the regulation of each country to which they export. Nowadays, all countries have good manufacturing, sanitary and hygiene regulations. Many countries also have specific canning regulations such as in the United States and Canada as well as HACCP regulations. Quality managers must follow carefully changes in regulations and implement them as they happen. They must also communicate these changes to all employees and verify their implementation. International food quality management standards such as IFS or BRC have included legislative compliance and monitoring in their basic requirements.

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Canning facilities have seen that regulations covering packaging materials and ingredients contamination are more liable to change than those relating to the actual canning process. New research and development, understanding and analytical capacity are responsible for these changes. The HACCP theory has also brought about a major milestone in the seafood canning regulations in identifying CCPs in the manufacturing process.

12.11

RESEARCH AND DEVELOPMENT

Most canneries make the same products over and over again. Canned fish products vary in terms of presentation, with or without skin and bones, different liquid covers such as oils, various sauces such as tomato sauce, brine or water, and with or without spices. In a cannery, research and development is usually initiated at the request of clients for a new recipe, new presentation or a new liquid cover. The canning process is likely to remain mostly the same whatever canned product is manufactured. In case of a change in the presentation or formulation of the sauce, the sterilisation process will need to be validated and might have to be changed. Temperature and time of sterilisation depends on many factors and heat penetration can be affected by the sauce formulation as well as the disposition of the fish in the can (see Management of Thermal Process, section 9.2.2). Another important issue is the evaluation of the expected shelf life of the new product which needs to be done by the appropriate person. Advice can be requested from knowledgeable institutions. It is important during the R&D process that all stages are fully documented, that decisions for progression through the stages of development are approved by all relevant departments, that HACCP considerations are reviewed, particularly in relation to any new raw materials (possibly containing allergens), and that the final detailed product specification is drawn up and is formally agreed between the company and potential customers.

12.12 SECURITY Product protection from vandalism and bioterrorism has become a real concern with the recent world events. More and more food standards have included requirements for security of the site and security of storage of materials, ingredients, packaging and finished products. Nowadays, sites are expected to be secured by gates, high walls, security personnel and security equipment whenever possible. Personnel movement must be monitored and documented on entrance or exit to and from the factory as well as in the production areas. Visitors and contractors must be identified as such and always accompanied or suitably supervised during their visits or intervention in the factory. A full analysis of all the possible dangers must be conducted and areas where and how they could be introduced into the process or into the product identified. Appropriate monitoring procedures must be put in place and their efficiency verified periodically to allow necessary adjustments. Storage areas for raw materials, ingredients, packaging and finished products must be secured and locked whenever appropriate. Authorised personnel should have access only to these locations and personnel movements in and out of theses areas should be controlled. The analysis of dangers should be updated on a regular basis to take into consideration any changes that might have occurred on the factory site and within the production areas. Employees should be sensitised on the possible security issues that might arise in the factory and should be encouraged to report any suspicious activities to management.

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12.13 CONCLUSION Safety and quality management in a cannery involves the cooperation of all team members from top management to the workers on the lines. In Section 12.1, the fact is discussed that most people do not realise the amount of work and care that is involved in canning, particularly in seafood canning. It usually takes the experience of working in a factory for a person to fully understand the process controls, the CCPs and the amount of time that is put in that process. In addition to the amount of work and controls required in seafood canning production, this process may be very repetitive and physically demanding for employees. Modern factories are automated and require considerably less human intervention, but in many countries most labour is done by employees who are directly in contact with the product, handling it with their hands until containers are sealed. The seafood canning production process as well as the control and quality process relies on human intervention and decision which necessitate careful monitoring. Training of employees and regular internal auditing of the whole process are very important to verify the efficiency of the quality management process. Over the past ten years, food safety and quality requirements influenced by scientific discoveries and epidemiological data have increased making canned seafood a safe product for consumers. A new challenge has appeared with concerns over the sustainability of the fish resource in the world.

ACKNOWLEDGEMENT All the Moroccan canning industry joins me in thanking Les Bratt for all his input throughout the years in Morocco, helping the sardine industry in this country meet the international requirement for safety and excellence.

REFERENCES Ababouch, L. (1995) Assurance de la Qualit´e en Industrie. Actes Editions, Rabat, Morocco. British Retail Consortium (BRC) (January 2008) Global Standard for Food Safety. The Stationery Office, London, UK. Code of Federal Regulations (1998) CFR 21 part 110, 113, 123. Office of the Federal Register, Food and Drug Administration, Washington, DC. Consernor (2008) Manuel Qualit´e. Safi, Morocco. Dillon, M. (1999) How to Clean. M.D. Associate, Lincolnshire, UK. International Food Standards (IFS) (August 2007) HDE Trade Services. Gmbh, Berlin, Germany. MD Associates (1996) How to HACCP. Lincolnshire, UK.

13

The laboratory in a fish canning factory

Linda Nicolaides and Les Bratt

13.1 LABORATORY FACILITIES 13.1.1

Scope of laboratories

With the advent of preventive, safety management systems based upon hazard analysis and critical control point (HACCP), the roles of the laboratory within a food-processing business are focused on verification that processes designed to eliminate specific hazards, or eliminate them to an acceptable level, have been achieved. There will inevitably be relatively simple quality control tasks that for practical expediency should be carried out on-site. Particularly in the case of small- and mediumsized processors however more complex, certification and validation work can also be carried out by commercial laboratories, which reduces the cost of establishing and running an in-house facility. The overall aims of the laboratory are to verify that all canned fish or fishery products produced on-site are of specified quality and are safe and fit for purpose with the primary aim to protect the health of the consumer, whilst providing them with information on ingredients, nutritional contents, any specific claims such as organic, Marine Stewardship Council chain of custody or the presence of specific food safety hazards that have been used as ingredients such as allergens (fish are recognised as allergen materials but further allergens may be present in spices or other components used in the manufacture of sauces). Typical analyses required within the scope of the on-site laboratory are likely to include:

r r r r r r r r r r r r r r

Physical inspection of raw fish for apparent quality and freshness; Measurement of histamine in raw fish and finished products; Measurement of volatile amines as a measure of freshness of fish (TVBN or ABVT); Measurement of salt content in brine or finished products; Measurement of brix content of tomato paste; Measurement of peroxide value of vegetable oil; Measurement of free residual chlorine in can cooling water; Incubation testing of cans of finished product; Microbiological swab testing of food contact surfaces; Testing of cleaned surfaces for allergens using propriety test kits; Compositional/component checking of finished product; Sensory evaluation of finished products; Heat penetration testing to validate thermal processes used; and Shelf-life testing of finished products.

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Typical analyses contracted to external accredited laboratories are likely to include:

r r r r r r r

Microbiological and chemical analyses of water used in processing or product make-up; Microbiological analysis of blown cans, including analyses for pathogens; Analysis of fish for heavy metals; Compositional analysis of vegetable oils; Analysis of fish for pesticides; Nutritional analysis; and Competence ring testing.

13.1.2

Location of laboratories

Laboratory facilities should be sited so that the environment and the location do not have adverse effects on neither the analyses carried out nor the results produced, nor should there be an opportunity for contaminating materials from the laboratory, especially if pathogenic microorganisms are involved, to be transferred into the raw materials, processing plant or finished product. For this reason, laboratories working on the same site as a processing facility should be situated in an independent structure, away from the food reception, processing and storage areas.

13.1.3

Laboratory competence

All analytical laboratories, whether working in a manufacturing business or outside a food business, should be able to demonstrate their competency in analytical procedures and compliance to good laboratory practice (GLP). In many cases accredited methods will be used, complying with the requirements of the ISO 17025 standard. Supporting this, evidence will exist, within the documented training records, of the competency and skills of laboratory managers and technicians in having the required analytical capabilities. With this competency laboratory managers and technicians are able to demonstrate a capability to participate in research, as well as provide analytical data compiled during monitoring and surveillance programmes that confirm compliance with product specifications and that might be used by the government and the food industry to carry out risk analyses. The BRC Standard for Global Food Safety requires that ‘Where the company undertakes or subcontracts analyses which are critical to product safety or legality, the laboratory or subcontractors shall have gained laboratory accreditation or operate in accordance with the requirements and principles of ISO 17025’. In certain countries the competent authority may have the necessary arrangements for certifying certain analytical techniques such as the determination of histamine used within site laboratories.

13.1.4

Laboratory design

Laboratories should be designed as secure facilities with access available only to authorised personnel. The design should also ensure that effluent materials including water, gaseous discharge from fume cupboards and general laboratory waste do not enter food-processing areas and provide risk of product contamination. The design of the laboratory should be such that it allows a logical process flow through the laboratory, from sample receipt to specialist areas for specific types of analysis, with results reaching an office where final results can be collated, analysed and stored. The structure of the laboratory should be self-contained and made from materials that can be cleaned easily to prevent any build-up of bio-films and other sources of possible cross-contamination. Utilities such

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as a potable water supply, distilled or de-ionised water, refrigerated storage and any gases needed for analysis should be available, supported by the appropriate safety features. Work surfaces should be made from non-porous materials so that they can be easily cleaned and sterilised before work, or if a spillage occurs. Separate areas within the laboratory are required for specific operations, including those for the receipt and preparation of raw materials, the preparation of microbiological media, including autoclaves together with the necessary environment controls and for the undertaking of physical and chemical analyses. It is also advisable to have specific pieces of equipment that might generate heat, e.g. that is used to carry out proximate analyses, or which are sensitive to the environment, housed in a room apart from the main laboratory. If the canning business is involved in new product development, then a separate facility with a pilot-scale retort and facilities for shelf-life determination should also be available and located away from the food production area. This is important, especially if it is planned to carry out challenge tests with known foodborne pathogens or spoilage bacteria, or if shelf-life trials are carried out on new products or processes developed on-site. Sensory analysis or taste panel testing should be conducted away from areas in which there is any likelihood of microbiological or chemical contamination of the materials being assessed. Bench tops in the laboratory should be impervious to water and other solvents, as well as being easy to clean. Fume cupboards and hoods should be provided to facilitate analyses that involve toxic or corrosive chemicals. The design should ensure that gaseous effluent is not discharged into processing areas. A risk-based approach should be followed when carrying out all laboratory-based activities. This will ensure compliance to the requirements of the Health and Safety Regulations and as well as providing information for the Control of Substances Hazardous to Health Regulations. Further information and guidance on these regulations can be found on the Health and Safety Executive website (www.hse.gov.uk).

13.1.5

Technicians and procedures

It is important that all laboratory staff can be demonstrated to be competent in tasks to the level appropriate to the duties that they are required to carry out. They should have a combination of experience and training in basic laboratory practices and have been proven competent in carrying out each specific analysis. If this is not done then the reliability and reproducibility of results produced by the laboratory may be suspect. Records of all technician training and competency assessment should be maintained in the staff training records. There should be a documented system in place that demonstrates that the laboratory is following GLP, based upon the requirements of ISO 17025, designed to support the laboratory workers in their day-to-day routine. All laboratory workers should enter information into laboratory logs, as a record of work carried out and work in progress. Laboratory logbooks might be in the form of either a laboratory book for each worker to record their individual results or a laboratory-wide system used by everyone to monitor what has been done and include the results obtained from each individual sample. Record forms should be identifiable by document number, properly authorised for use and part of a controlled document system. It is important to be sure that whichever system is in place the traceability of samples is maintained. Laboratory records should be kept so that they are easily retrievable for a duration in excess of the stated shelf-life of the products manufactured. Recognised standard methods, such as those published by the International Standards Organisation (ISO – www.iso.org) or in the AOAC Official methods of analysis textbook, should be followed for all routine analyses. The AOAC methods are also available on a CD ROM.

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13.1.6

Sampling plans

Sampling plans are needed, as it is never possible to test 100% of any lot produced. However, when products are manufactured and supported by an HACCP system, sampling and testing of the end product is a method of verifying that the process is under control and that the end product meets legislative, customer quality and safety requirements. Sampling plans should be followed and used according to the requirements of the investigation, e.g. either sampling to verify that the process is under control and that the product is commercially sterile or investigating a specific problem. Other factors that should be considered when deciding the number of cans to be sampled include the nature of the lot, the nature of the product under investigation, normal variations in the product and the laboratory tests that will be used. The statistical significance and the level of confidence of the sample removed for analysis should be understood. There are examples of sampling plans which address the number and location of cans to be removed for analysis in subject specialist literature. Procedures and standard operating procedures (SOPs) will support the reliability of laboratory results obtained from all analyses. Similarly, technicians deemed competent to carry out analyses of canned food samples will be trained to take necessary care so that all results can be relied upon.

13.2

CHEMICAL ANALYSES

SOPs for all routine tests should be documented within the laboratory quality management system. The most up-to-date method of any standard test should also be available. Test procedures for routine analysis can be found in the latest version of the AOAC Official Methods of Analysis (2007) or on the website of the International Standards Organisation (ISO). Preventive maintenance programmes and routine calibration of equipment used for weights and measures should also be in place. There should be a list of all equipment subject to calibration that includes the type of equipment, the serial number, where deployed, the accuracy required, the resolution of the equipment, the method used for calibration, the calibration frequency and the agency responsible for calibration. Evidence should be in place to demonstrate that the methods used have been validated and that all technicians with responsibilities for carrying out specific analytical methods have been demonstrated to be competent in these activities. Wherever necessary, standard reference materials should be included in the routine analysis to confirm that the analysis is being carried out correctly. The establishment of SOPs for each analysis will contribute to uniformity in how each specific test is carried out by different operatives working within the same laboratory. Such methodologies can also be used to reduce errors when ring tests are carried out between different laboratories. The SOP can also be used to train new members of staff or provide refresher training for staff with the aim to reduce the risk of human error. One of the most important chemical analyses for manufacturers of canned fish products such as sardines, mackerels or tuna is that of histamine. Histamine is generated by microbiological action on the chemical compound l-histidine which is naturally present in scombroid species of fish and may give rise to physiological reaction in consumers such as nausea, vomiting, facial swelling, head aches, itching and burning sensations in the mouth. The legal limit for histamine in canned fish within European legislation (EC 2073/2005) is 100 mg/kg with no more than two samples in nine having up to 200 mg/kg. In commercial practice however most purchasing organisations impose a specified limit of 50 mg/kg or even lower. There are three methods commonly in use for the measurement of histamine, the traditional method of spectrofluorimetry, perhaps the most

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accurate method of HPLC and the more recent and rapid method using ELISA kits. All methods are of sufficient accuracy for the intended purpose. The choice of method used may be specified by the local competent authority, but otherwise will depend on the cost of capital equipment and the daily costs of the necessary reagents. The Food Standards Agency of the United Kingdom commissioned a research project EO1045 into the different methods of analysis for histamine and a copy of the report is available on request to the FSA Library and Information Centre.

13.3 MICROBIOLOGICAL TESTING Microbiological testing of canned food is used to verify the safety status of a food, whether it is a raw material, a product in preparation or development or the final product. Sampling plans and methods of analysis will be designed to verify that the food complies with pre-specified requirements that are part of the HACCP plan or legislative requirements. The safety and quality attributes of raw fish used in the final product will be assured through the control measures presented in the HACCP plan, e.g. agreed raw product specifications, confirmation of freshness attributes and temperature control upon receipt of the fish. The role of microbiological analysis is to verify that the agreed attributes are as they should be, that canned fish is commercially sterile and for investigation into any incidence of post-process spoilage. Specific microbiological analyses are used to validate process steps declared as Critical Control Points. For example the retorting stage is designed to eliminate all vegetative bacteria and all pathogenic spore-forming bacteria from inside the cans. By convention all low-acid foods (pH >4.5) are heat processed to a minimum F0 value of 3 but in practice actual values are invariably higher than this to allow for minor irregularities in product and process conditions. Microbiological tests can also be used to confirm that the process designed for a particular product in a specific container is meeting customer and legal requirement for safety and quality. The overall purpose of preserving fish by canning is to produce a commercially sterile product. Microbiological analyses would be expected to produce negative results as microorganisms should not be present in the cans. Incubation of the cans is used to promote the growth of any surviving microorganisms, which will indicate problems associated with the effectiveness of either the thermal process applied or the post-process sanitation. Incubation testing may be used as a tool in the confirmation of commercial sterility but it is important that the statistical significance of the testing is fully understood. More information is provided in Campden BRI publication G34, Guidelines on the Incubation Testing of Ambient Stable Heat Preserved Foods. Within the processing plant, microbiological screening can be used to verify that the plant and equipment have been cleaned and maintained to the required standard. Such tests are usually taken after the routine cleaning operations have been carried out and the results used to support the due diligence defence of the company. Screening of staff by taking hand swabs or stool samples can also be used to demonstrate that they are not carriers of enteric pathogens or other pathogenic bacteria. As well as traditional methods of analysis there are a range of rapid methods and test kits on the market that allow routine monitoring to take place in ‘real time’. If the result of the rapid test indicates that a surface has not been cleaned correctly, then further cleaning can take place to prevent any cross-contamination of microbial loads from one batch to another. Further kits are also available to validate the successful cleaning of plant from allergen materials in order to prevent the cross-contamination of products which do not contain the same allergens.

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13.4 ANALYSIS REQUIRED FOR CANNERY WATER AND RETORT COOLING WATER A pre-requisite requirement of the HACCP system requires that all water that comes into contact with product is of a potable quality. This should be held in a network of pipework that is identified as potable water distinctly marked to differentiate it from the non-potable water supply if present in the cannery (certain countries have legislation regarding the colour coding of water pipes). If water is supplied from the local water company, they should provide the food business with a certificate of conformance, supported by microbiological and chemical data-confirming potability. Should there be a problem with the water supply, it is the responsibility of the local water authority to provide food businesses with a warning not to use the supply. If such an alert is issued then the water authority will be expected to have a crisis management protocol and give the all-clear when the problem has been resolved. The cannery would also be expected to take samples for analysis from a number of sampling points on a periodic basis to verify that the water board is supplying the quality of water that is required for production of the canned product and that contamination is not occurring in the factory itself. Canneries are only expected to assess the bacteriological load of water by doing an aerobic plate count at 22◦ C if supplies exceed 10 000 m3 per day. Standards for potable water are based on Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption. Microbiological requirements

Parametric value (number/100 mL)

Escherichia coli (E. coli) Enterococci

0 0

Water samples for microbiological analyses should be collected in sterile containers, containing a 10% solution of sodium thiosulphate (2 mL of 10% sodium thiosulphate per litre of sample). Samples should be tested immediately or held in a refrigerator for no longer than 2 hours. The sanitation of water used for the cooling of sterilised cans is of vital importance to prevent post-process infection. The concentration of free residual chlorine in the cannery cooling water, present before and after cooling, should be monitored on a regular basis during the processing period, typically using DPD reagent, as this represents a CCP in preventing the leakage of potential spoilage or pathogenic bacteria into the cans during the cooling stage.

13.5 SWAB TESTING Swab testing has been a traditional method used by microbiologists for many years to assess the microbial load of a range of surfaces. It used to be the preferred method to verify whether a surface, a conveyor belt, an operator’s hand after washing or the inside of a piece of equipment had been cleaned correctly. However, as with all microbiological methods, results were not available until after 2/3 days. Procedure: A non-absorbent cotton wool swab is dampened using sterile maximum recovery diluent (MRD), a 10-mL aliquot in a universal container. The swab is then gently rubbed over a defined area of the chosen surface, usually 100 cm2 . The swab is first rubbed over the area from right to left by rotating the cotton wool swab. Then the swab is rubbed against the same area with

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an up/down action. The swab is then transferred to a universal container with 10-mL quantity of MRD and the wooden stick is broken so that the cotton wool is immersed in the diluent. The contents of the universal container is mixed together on a mechanical agitator for 2 minutes and used to prepare a tenfold dilution in 9.0-mL quantities of MRD. Finally 0.1 mL of each of the tenfold dilution series is transferred to the surface, and spread evenly over a pre-poured Plate Count Agar plate, duplicate plates are used for each dilution. After incubation for 2/3 days at the selected temperature the number of colonies that have grown can be counted and the bacterial count for the 100 cm2 can be presented. Over recent years more rapid methods have been developed to provide virtually instant results. A good example of such a test is based upon the detection of adenosine triphosphate (ATP) using a bioluminescence reaction. ATP is present in all living organisms, including microorganisms. Hence the level of ATP present on a surface can confirm that the surface has been cleaned adequately. The ATP reaction is based upon ATP reacting with luciferin and luciferase enzyme, which produces the emission of light (one photon is emitted for each molecule of ATP present). The light is detected by a hand-held luminometer, proving the result in a few seconds. Kits are available to perform the ATP-based hygiene swabs from companies such as Hygiena International Ltd.

13.6 INCUBATION TESTS Incubation testing is used to promote the growth of microorganisms in canned foods that might be present as a result of under-sterilisation or post-process infection. Two incubation regimes are typically used, 37◦ C for 10 days for the detection of mesophilic organisms (including all relevant pathogens) and 55◦ C for 7 days for the detection of thermophilic spoilage organisms. Incubation testing may be undertaken as part of the company’s own quality management programme, at the specification of customer organisations or may be a local statutory requirement. What is vitally important however is that the statistical significance of the testing is fully understood so that results are properly meaningful. Small sample size incubation testing should never be used as the sole means of determining the adequacy of the thermal processes used in the attainment of commercial sterility. Statistically if a defect has occurred so that one can in n is affected, a sample size of 3 n would be necessary to be 95% certain of detecting the fault (if 1 can in 100 is affected the sample size required is 300). Incubation testing may be used as an investigation tool in the event of:

r r r r

An observed deviation to a thermal process; Suspected deficiency of can closures or sanitation of cooling water that might increase the likelihood of post-process spoilage; Routine surveillance using large-scale incubation for container failure rates; and Change of product or processing equipment.

Detailed information on incubation testing is provided in Guideline No 34, The Incubation Testing of Ambient Shelf Stable Heat Preserved Foods, produced by Campden BRI.

13.7

STERILITY TESTS

Canned foods are heat processed to a condition of commercial sterility. This provides for the destruction of all pathogenic microorganisms including most importantly the spores of Clostridium

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botulinum together with all spoilage microorganisms capable of growth under the designed ambient storage conditions of the finished product. Spoilage of canned foods may occur for two reasons, under-sterilisation or post-process leaker infection. Commercial sterility is obtained by the correct scheduling of the required thermal process and the application of good manufacturing practice in compliance with the company’s HACCP plan. Microbiological methods are sometimes used however to check commercial sterility and also to examine cans that have been subject to spoilage.

13.7.1

Examination of containers

All cans which have been taken for testing should be given a unique number. The cans are marked with this number in a place that will not interfere with opening or examination of the cans or their seams. Cans are weighed and the appearance of each can recorded, in respect to dents or faulty seams that are visibly apparent at this stage. Information on the label and or markings on the can should be noted to confirm the date of production for traceability purposes. Once the samples have been removed for microbiological examination, the structure of seams should be assessed to verify that they comply with specifications. The technique involves pre-incubating intact cans at different temperatures (usually 37 and 55◦ C), opening the cans and culturing any microorganisms that might be present onto different culture media. The purpose of pre-incubation is to encourage any viable cells present inside the cans to increase in numbers which would aid the subsequent sampling of the contents of the can. Cans should be observed regularly during the incubation period to see if there are any signs of distortion or leakage. If the cans are seen to be leaking or the ends distended then the cans should be removed from incubation and sampled immediately. Swollen cans are examined upon receipt, as pre-incubation might encourage further gas production and explosion of the cans. It is also advisable to identify the reason why the cans have swollen. It might be due to chemical reaction of the product and the can lining, in which case microorganisms would not be present. Alternatively, microorganisms might have grown and produced gas causing the cans to swell, so further incubation is not necessary.

13.7.2

Cleaning of container

Cans should be cleaned thoroughly before being opened and samples taken for microbiological analysis. Labels should be removed carefully and kept for providing information on the contents of the cans. Some cans are pre-printed so that relevant information should be copied or photographed before the analysis commences. The cans should be washed in soapy water and then rinsed. The areas to be opened should also be cleaned in chlorinated water (100–300 ppm).

13.7.3

Opening of the container

Protocols to prevent contamination of the sample need to be addressed when sterility checks are carried out. The end to be opened should be in alcohol, excess alcohol tipped off and the end flamed carefully to ensure the can end is sterile. N.B. Swollen cans should not be flamed as this might cause the can to explode.

The laboratory in a fish canning factory

13.7.4

259

Sub-culturing of the sample

Cans should be opened inside a safety cabinet to prevent contamination of the can and its contents, using a pig sticker or similar device, to prevent disturbing the seams on the end that has no printed information, usually the canners end. Using a sterile ‘pig sticker’ the can should be opened by making a hole in the centre of the sterile end and cutting out a circle of metal approximately 25 mm in diameter. A sterile glass funnel should be placed over the can during opening in case there was pressure inside the can to prevent the content from escaping as an aerosol into the cabinet/laboratory. Any signs of positive pressure inside the cans should be recorded. The appearance, condition and odour of the can contents should be recorded before any sample is taken for further examination. Approximately 250 g of the can contents should be transferred to a sterile stomacher bag using sterile implements. If the contents are solid then samples should be taken from the central region of the contents (evidence of underprocessing), as well as from the areas close to the seams (evidence of ‘leaker’ spoilage). Once the contents of the cans have been sampled the remaining fish or fishery product should be transferred to a sterile plastic bag, labelled with the unique number and placed into a freezer for storage, until the results of the cans have been reviewed and agreed. This sample can be re-examined should any problem be identified with the product. In addition the condition of the internal surface of each can should be checked and observations made, e.g. if the lacquer is entire or corroded. The sample should be diluted with 100 mL of MRD in the stomacher bag and the contents gently massaged by hand or put into a Colworth Stomacher for 2 minutes to release bacteria from the sample mixture. A loopful of the suspension in the stomacher bag should be streaked onto each of six plates of dextrose tryptone agar (DTA). Incubate one of these plates under each of the following conditions: 30◦ C (48/72 hours) aerobically and anaerobically; 37◦ C (24/48 hours) aerobically and anaerobically; 55◦ C (5/7 days) aerobically and anaerobically. A loopful of the contents should also be transferred to a microscope slide to prepare a smear, which should be air-dried and gram-stained. The completed stained smear should be observed for the presence of microorganisms and results should be recorded. A further sample of the can contents should be placed into a sterile, disposable 50-mL container together with 20-mL sterile distilled water. This sample is used to determine the pH level of the can contents. The contents of the stomacher bag should be used to inoculate the following laboratory media. A 1-mL sample should be added to each of the following:

r r r

Nine tubes of TSB; Six tubes of CMM, overlaid with sterile mineral oil to aid anaerobiosis; and Two tubes of iron sulphite agar.

The inoculated tubes should be incubated under the following conditions:

r r r

3 × tubes TSB and 2 × tubes CMM at 30 ± 1◦ C for 5 days; 3 × tubes TSB and 2 × tubes CMM at 35 ± 1◦ C for 2 days; and 3 × TSB and 2 × CMM with the iron sulphite agar at 55 ± 1◦ C for 5 days.

At the end of the incubation period the tubes should be observed for signs of microbial growth, e.g. gas production, cloudy broths, blackened meat blackened. The tubes should then be sub-cultured onto TSB agar plates and incubated under the same condition as the tube they were inoculated from, e.g. TSB broth – TSBA plates incubated aerobically: CMM broth, TSBA plates should be incubated

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anaerobically. The iron sulphite agar will have black dots throughout the tube if the sample contains sulphite reducing anaerobes. During and at the end of the incubation period the tubes should be observed for signs of visible growth including evidence of gas production or proteolytic activity in the CMM. After the appropriate time each tube should be sub-cultured onto a DTA plate. Plates should be incubated at the same temperature as that used to prepare the sub-cultures in tubes. Plates inoculated from TSB should be incubated aerobically and plates inoculated from the CMM incubated anaerobically. Plates sub-cultured from tubes incubated at 30 ± 1◦ C for 3–5 days; 35 ± 1◦ C at that temperature for 1–2 days and plates sub-cultured from the tubes incubated at 55 ± 1◦ C at that temperature for 5–7 days. After incubation all the plates should be examined and the results recorded. Plates positive for microbial growth should be examined further. Colonies should be assessed and sub-cultured to confirm purity before being prepared for a Gram stain.

13.7.5

Interpretation of results

Sterility testing of cans of fish and fishery products should usually result in negative growth. However, should any of the enrichment broths contain positive results the following table can be used to interpret the results. Fish and fishery products are considered as low-acid canned foods.

13.8 LABORATORY ACCREDITATION ISO 17025:2005 provides the general requirements for the competence of testing and calibration laboratories. The standard should be used as a guide to establish a quality management system within the laboratory and provide focus on specific laboratory protocols or procedures. The standard bears considerable commonality with the logic of ISO 9001.2000 and is applicable to all laboratories regardless of the number of personnel or the extent of the testing or calibration activities. Essentially the standard includes two main sections: the management requirements and the technical requirements. The latter include:

r r r r r r r r r r

General Personnel Accommodation Test and calibration methods and method validation Equipment Measurement traceability Sampling Handling of test and calibration items Assuring the quality of test and calibration results Reporting of results

FURTHER READING AOAC (2003) AOAC Official Methods of Analysis, 17th edition, CD-ROM. AOAC (2007) AOAC Official Methods of Analysis, Revised 2nd edition.

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BRC Standard for Global Food Safety (Issue 5, 2008). EO1045 (2006) Evaluation and Development of Methods for the Determination of Histamine in Food. Foods Standards Agency, London. Campden BRI Examination of Suspect Spoiled Cans and Aseptically Filled Containers, Technical Manual No 18, Chipping Campden, GL55 6LD, UK. Campden BRI Microbiological Control in Food Industry Process Waters: Chlorine Dioxide and Bromine as Alternatives to Chlorine, Guideline No 15, Chipping Campden, GL55 6LD, UK. Campden BRI (2001) Guidelines on Incubation Testing of Ambient Shelf Stable Heat Preserved Foods, Guideline No 34, Chipping Campden, GL55 6LD, UK. CEN/CENELEC (2005) General Requirements for the Competence of Testing and Calibration Laboratories (BS EN ISO/IEC 17025:2005). Hersom, A.C. and Hulland, E.D. (1980) Canned Foods: Thermal Processing and Microbiology, 7th edition. Elsevier Health Science, Kidlington, Oxford, OX5 1GB, UK.

14

Cleaning and disinfection in the fish canning industry

Peter Littleton

14.1 INTRODUCTION With all food production processes both equipment and surfaces become contaminated with food residues, foreign bodies and microbial contamination. The removal of these contaminants, soil, is the process of cleaning. Cleaning should always be considered as an essential and integral part of the production process for many reasons. Namely:

r r r r r r r r

Legislation – The Food Safety Act 1990, UK and EU regulations require that effective hygiene standards are implemented for anyone who handles, manufactures or serves food; For microbial control – reducing bacterial numbers to an acceptable level for the product being produced; Removing physical or chemical contamination; Foreign body control; Performance of the plant (e.g. removal of build-up on heat exchangers); Safety of the plant and operatives; Discourage pests; and A pleasant and clean work environment to create the right impression for all.

Cleaning needs to be carried out in such a manner that it is effective, efficient, without causing damage to personnel, equipment or surfaces and without causing cross- or re-contamination. Before looking at the specific challenges and issues faced in the fish canning industry, we must first consider the fundamental requirements and methods that can be employed to ensure that safe food-manufacturing environments are achieved.

14.2

THE CLEANING PROCESS

The timing and frequency of cleaning needs to be set by risk assessment of the product and the process. During the production and processing of the product, contact surfaces will become contaminated with soil and microorganisms. This contamination may lead to deterioration in product quality and eventually an unacceptable product. By assessing product quality against production running time a frequency of cleaning can be determined that ensures product quality always remains acceptable; in addition, potential cross-contamination risks from the cleaning process must be identified and risk assessed. In practice there are several ‘categories’ of cleaning that can be undertaken in food production environments.

Cleaning and disinfection in the fish canning industry

Fig. 14.1

14.2.1

263

Effect of periodic cleaning. (With permission from Holchem Laboratories Ltd.)

Interproduct cleans

An Interproduct clean is used when a production line is changing product or species and requires residue to be removed. This removes physical contamination such that the subsequent product does not contain components of the previous production run and techniques employed tend to use manual cleaning or low-pressure rinsing systems.

14.2.2

Timed clean

Cleaning after a defined time period is appropriate for certain equipment. With continuous production a potential for increasing soil and microbial loading on food contact surfaces exists; this can be controlled by suitable periodic cleaning (see Figure 14.1).

14.2.3

Hygiene clean

A hygiene clean or an end of production clean refers to a thorough stripdown of equipment to allow full access to all surfaces and routine entrapment areas. This is usually carried out when no other production is taking place nearby and when all work in progress or finished product has been cleared away from the vicinity.

14.2.4

Deep clean

Certain areas or parts of equipment, such as electrical control cabinets, may not be accessed during the hygiene clean. These areas of the equipment are not deemed to pose a day-to-day contamination risk and are cleaned for instance every 3 months; these are often referred to as deep cleans.

14.2.5

Good cleaning practices

Cleaning a food production environment requires considerable coordination by the cleaning crew to ensure that it is effectively and efficiently cleaned without introducing cross-contamination risks. Some of the considerations are:

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Preparation of the area and equipment

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Remove all product from area before starting; Cover electrical components; and Ensure all cleaning equipment is clean and disinfected, e.g. brushes, cloths and pads.

Cleaning

r r r r r r r r r r r

Adhere to the agreed method; Pay attention to detail; Follow the correct procedure and sequence of clean; Carry out checks on the cleaning process including: level of strip of equipment, chemical strengths, temperatures and contact times with detergents and disinfectants; Run hosepipes underneath machinery and equipment; Do not place dirty items onto clean or vice versa; Work in a top to bottom manner; Clean in a safe manner – do not take risks, wear personal protection equipment; Do not clean machinery parts or equipment on the floor; Keep clean and dirty items separate; and Wash hands regularly, particularly after handling dirty items.

Reassembly

r r

Inspect all surfaces before reassembly and reclean if necessary; and Disinfect surfaces before and during reassembly using only hygiene-trained personnel.

14.3

PRINCIPLES OF CLEANING

Cleaning involves detaching soil from a surface and the removal of it to waste. In wet cleaning this means the detergent has to detach the soil and then suspend it in the cleaning solution until it reaches a water treatment plant. With dry cleaning it generally involves removing to a waste bin via a brush and a dustpan or via a vacuum cleaner.

14.3.1

Cleaning energies

With wet cleaning thermal, chemical and physical energy are used in combination to remove the soil from a surface (see Figure 14.2). The balance of energies depends on the physical process and the detergent type; some involve low chemical energy (such as neutral detergents) combined with high physical energy (scrubbing) and others involve high chemical energy (acidic descaler) with little physical energy. The greater the attachment of the soil to a surface, the greater the combined energy required for cleaning. Contact time with a detergent is necessary to maximise its performance; generally the longer the contact time with a detergent the less physical energy will be needed to remove the soil from the surface. Temperature is important since it increases chemical reaction speeds between detergent and soil and is also essential for the effective emulsification of fats where present.

Cleaning and disinfection in the fish canning industry

Fig. 14.2

14.3.2

265

Cleaning energies. (With permission from Holchem Laboratories Ltd.)

Choice of detergent

The role of the detergent is to assist in the removal of soil from a surface. The choice of the detergent has to be made when a number of factors have been considered. These include soil type, method of application, materials of construction of the surfaces being cleaned, water hardness, health and safety and many others. Most detergents combine emulsification properties with some type of chemical reaction. Although there are thousands of detergent products available in the professional and domestic market, they break down, broadly speaking, into the following:

r r r

r r

General purpose neutral or mildly alkaline detergents are used for hand cleaning by spraying or for soak cleaning (sinks). They rely largely on emulsification and suspension of soiling and are particularly effective on fats and oils. Sanitisers are neutral, mildly acidic or mildly alkaline detergent disinfectants that combine the cleaning properties of a neutral detergent with a degree of disinfection. Highly alkaline detergents are used where heavier soiling is encountered. They rely partly on chemical reaction to hydrolyse proteins or saponify fats. They can be applied in a number of formats including gels or foams for long contact times with open surfaces or as low foam products for recirculation cleaning such as dishwashing, tray washing and cleaning in place (CIP). They are effective on highly carbonised or polymerised soils. Highly alkaline chlorinated detergents, either as foams or as low foam products for recirculation, are used because of their excellent removal of the fats and also proteins, in particular the protein scale commonly encountered in fish-processing operations. Acidic detergents can be used for mineral scale removal and protein removal. These are of particular use for descaling operations in static retorts and blanchers.

14.4

OPEN PLANT CLEANING

Open plant cleaning can be carried out either as a wet or as a dry process depending on the nature of the soiling present, the product, the process and type of production equipment. Dry cleaning is

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Fig. 14.3

Dry cleaning. (With permission from Holchem Laboratories Ltd.)

used mainly for processes where dry or particulate products are handled. Wet cleaning is employed wherever possible due to the higher efficacy of the wet cleaning process (better soil removal from surfaces).

14.4.1

Dry cleaning

Dry cleaning (see Figure 14.3) refers correctly to cleaning where no liquid detergents or disinfectants are used; however, it is also commonly used to refer to cleaning where disposable impregnated wet wipes or damp disposable cloths are used. In the food industry it is usually found in processes where the presence of water could affect the quality and consistency of the product, such as spice or coating make-up areas or create conditions that enhance microbial growth. Dry cleaning is a purely mechanical process that relies on the soil being physically removed (brush, vacuum). The nature of brushes and vacuums mean that 100% soil removal of soils will not be achieved (Holah et al., 2004). Consideration must be given to following brushing or vacuuming with wiping with detergent/disinfectant dampened cloths to increase overall soil removal.

14.4.2

Cross-contamination by dry cleaning

Tools used for cleaning can become a major route of cross-contamination. Cloths and scourers should be disposed of after use. Brushes, scrapers and other tools must be cleaned, disinfected and stored hygienically for later use. Tools should be clearly defined for area of use, for example, floor use only or food contact use only. A colour code system can be used (see Figure 14.4) for this. It is vitally important that the system is clearly defined and managed. Airlines are sometimes used to dislodge soil from difficult-to-access areas, essentially moving it to an area that can be accessed by a dustpan and a brush or vacuum. Unfortunately, airlines will

Cleaning and disinfection in the fish canning industry

Fig. 14.4

267

Colour coding. (With permission from Holchem Laboratories Ltd.)

impart energy to fine particulate matter, making it airborne and allowing it to spread over large areas.

14.4.3

Manual cleaning

Manual cleaning refers to the cleaning process where the detergent is applied via a cleaning tool such as cleaning cloth, scourer or brush (see Figure 14.5). It also refers to cleaning of parts that are put to soak in detergent solution before physical action. Manual cleaning of machinery, equipment and surfaces is the most common method employed throughout the food manufacturing industry. Manual cleaning provides a flexible method of cleaning for a variety of equipment and surfaces and has little risk of cross-contamination caused by aerosols or overspray; however, the control and cleaning of cleaning tools are vital to ensure no crosscontamination. With manual cleaning there is a substantial contact between the operative and the chemical being used to clean; therefore, the type of detergent used must be carefully considered. It will usually involve a 1–2% v/v solution, at typically 40–45◦ C, of either a neutral detergent, a quaternary ammonium compound (QAC)-based detergent or a light/medium duty alkaline detergent. These light duty detergents will not perform as well as the higher alkalinity products on fat or protein soils.

14.4.4

Foam and gel cleaning

Foam cleaning refers to the cleaning process where the main detergent is applied as foam and gel cleaning refers to the cleaning process where the main detergent is applied as a gel (see Figure 14.6). Gels can also be aerated during application; this is called a mousse.

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Fig. 14.5

Manual cleaning. (With permission from Holchem Laboratories Ltd.)

With increasing commercial and technical pressure placed on the food-manufacturing industry the time window and manpower required for cleaning has been squeezed and decreased. Foam cleaning has proven to be a very effective, efficient and popular method for cleaning of rooms and equipment. The improvement in foam technology, such as long cling foams, and the introduction of different types of foam detergents have made it a process that can be used, with benefit, in many situations.

Fig. 14.6

Foam cleaning. (With permission from Holchem Laboratories Ltd.)

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Foam is created by mixing water, detergent and air together and applying it via a hose with a special nozzle or lance onto the surfaces and equipment. The foam detergent will typically be applied at 3–5% v/v, depending on the soil to be removed and water hardness. The main advantages of foam and gel cleaning in comparison to manual cleaning are as follows:

r r r r r r

The detergent solution can be applied to large and difficult-to-reach areas in a short period of time; An extended detergent contact time between the soil and the detergent; A reduction in the time of cleaning; Less manpower required; Control of detergent use; and Safer application of hazardous detergents.

A common misconception of foam and gel cleaning is that it negates the need for any type of physical action (such as scrubbing with a brush or scourer). Physical energy must be applied after suitable detergent contact time. The physical energy can be applied either by scrubbing or by energy from a water jet typically either high or medium pressure.

14.4.5

Cross-contamination by wet cleaning

A washdown system provides the hygiene operative with an efficient tool for rinsing away soil and detergent (see Figure 14.7). The water jet provides a degree of physical energy to a surface that assists in the removal of the soil. The higher the pressure of the system, the higher the impact energies available. Medium pressure systems operate at typically 20 bar with a flow rate at the nozzle of 30 L/minute. This gives very similar cleaning energies to a high-pressure systems operating at 70 bar and with

Fig. 14.7

Wet cleaning. (With permission from Holchem Laboratories Ltd.)

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a flow rate at the nozzle of 15 L/minute. Low pressure systems operate at typically 5 bar with a nozzle flow rate of 40–50 L/minute. Both medium- and high-pressure systems provide sufficient cleaning energy to remove most of the soiling if the correct foam or gel detergent has been used. With low-pressure rinsing however, this is not the case and it is essential that surfaces are scrubbed prior to rinsing. All washdown systems, whether low, medium or high pressure, will cause overspray which can lead to cross-contamination if no controls are put in place; however, high-pressure systems also create aerosols which add another vector of cross-contamination. As discussed in the section on dry cleaning, tools are a major source of contamination. Cleaning tools and their management generally receive low priority; this was aptly demonstrated in a food industry-wide survey by Campden BRI which showed that of all cleaning tools tested 35% were Listeria positive. The correct choice of tools, the management of cleaning of tools and the designation of specific tools for different purposes (usually identified by a colour coding system) is essential.

14.5 FLOOR CLEANING Floor cleaning can be carried out using manual methods such as a mop/brush and a bucket, by utilising the washdown system or by a dedicated floor cleaning machine (see Figure 14.8). The most appropriate method will depend on the access to the floor area, the time of cleaning and the size of the floor area. With manual and washdown methods the detergents used are generally the main detergents used for the equipment and wall cleaning; since the type of soil encountered will be the same. With floor cleaning machines the detergent is usually a low foam alkaline detergent.

Fig. 14.8

Floor cleaning. (With permission from Holchem Laboratories Ltd.)

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All methods create overspray which can travel vertically onto food contact surfaces. Work by Campden BRI showed that the potential for cross-contamination of food contact surfaces from floors was real and measurable. The distance of vertical and horizontal travel by floor cleaning solutions varied dependent on the method of cleaning (Holah et al., 1993). The greatest vertical and horizontal travel of cleaning solutions occurs when using a high-pressure washdown gun, followed by medium-pressure washdown gun, low-pressure washdown gun, floor cleaning machine with mopping and brushing creating the least travel.

14.6 TRAY AND RACK WASHING MACHINES Washing machines are used to automatically or semi-automatically clean trays, racks, utensils and, in the case of dishwashers, crockery and cutlery (see Figure 14.9). Because of the high volume of trays, baskets, tubs, containers, etc. required by many modern food businesses, it has become unrealistic and uneconomic to clean manually. A large bakery, for example, may require 2500 baskets an hour to keep a continuous production flow. Washing machines come in many shapes and sizes and are generally built for the cleaning of a specific size and type of item. Washing machines should be used only for the original purpose they were intended. The short contact time with detergent and the relatively low impact energies of the wash nozzles means that to clean effectively high chemical energies are required. In most situations a high alkaline low foam detergent at 0.25–1% v/v is used at 55–75◦ C. The washing machines must be managed correctly with regular cleaning of the machine and filters, regular changing of wash solutions, inspection of wash and rinse nozzles and control/monitoring of detergent temperatures and strengths.

Fig. 14.9

Traywashing. (With permission from Holchem Laboratories Ltd.)

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Fig. 14.10

Tunnel traywash. (With permission from Holchem Laboratories Ltd.)

Washing machines are either tunnel-type machines or single-tank machines. With tunnel-type machines (see Figure 14.10) items are placed on a conveyor which transports them through a number of stages of the washing process. Each stage occurs in a different section of the washer; pre-rinse, wash with detergent, rinse, disinfect chemically or by temperature and then dry. With single-tank machines the item is placed in a cabinet and the wash process takes place in the cabinet by sequencing the cleaning stages (pre-rinse, wash, rinse, disinfect). The efficacy of a clean is dependent on correct original design of the machine for the items being cleaned and correct operation and maintenance.

14.7 PRINCIPLES OF DISINFECTION Disinfectants work by absorbing onto any microbial cell; this absorption increases the permeability of the cell membrane, ultimately leading to rupture and leakage of the contents of the cell and causing the cell to die. Concerns have been raised by the resistance of microbes to the use of disinfectants. This research mainly pertains to environments such as hospital theatre standards, and it is unlikely to be of concern in food-manufacturing environments. Additionally, the disinfectants concerned were based on single active ingredients and most of the disinfectants used in the food industry contain more than one active ingredient. Note that a common misunderstanding is between the modes of action of disinfectants and antibiotics. Investigation of instances of perceived resistance in the food-manufacturing/processing industry has been found to be the result of:

r r r

Sub-lethal concentrations of disinfectant; Dilution of the disinfectant by application onto a wet surface; and Presence of detergent residues which inactivate the disinfectant.

The ideal chemical disinfectant should:

r r r r r

Be suitable for food contact surface application; Have a wide range or scope of activity; Destroy microorganisms rapidly; Be stable under all types of conditions; Be tolerant of a broad range of environmental conditions;

Cleaning and disinfection in the fish canning industry

r r r

273

Be soluble and possess some detergency; Be low in toxicity and corrosivity; and Be inexpensive.

14.8 14.8.1

FACTORS AFFECTING DISINFECTANT EFFECTIVENESS Physical factors

Surface characteristics Prior to the disinfection process, all surfaces must be clean and thoroughly rinsed to remove any detergent residue. An unclean surface cannot be disinfected. Since the effectiveness of disinfection requires direct contact with the microorganisms, the surface should be free of cracks, pits or crevices which can harbour microorganisms. Surfaces which contain bio-films cannot be effectively disinfected.

Exposure time Generally, the longer time a chemical is in contact with the equipment surface, the more effective the disinfection effect; intimate contact is as important as prolonged contact.

Temperature Temperature is also positively related to microbial kill by a chemical disinfectant. Avoid high temperatures (above 55◦ C) because of the corrosive nature of most chemical disinfectants at elevated temperatures.

Concentration Generally, the effectiveness of a disinfectant increases with increased concentration, however, a levelling off occurs at high concentrations. A common misconception regarding chemicals is that ‘if a little is good, more is better’. Using disinfectant concentrations above recommendations does not disinfect better and, in fact, can be corrosive to equipment and in the long run lead to a reduction in cleanability. Follow the manufacturer’s label instructions.

Soil The presence of organic matter dramatically reduces the activity of disinfectants and may, in fact, totally inactivate them. The adage is ‘you cannot disinfect an unclean surface’.

14.8.2

Chemical factors

pH Disinfectants are dramatically affected by the pH of the solution. Many chlorine disinfectants, for example, are almost ineffective at pH values above 7.5.

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Water properties Certain disinfectants are markedly affected by impurities in the water.

Inactivators Organic and/or inorganic inactivators may react chemically with disinfectants giving rise to nonbactericidal products. Some of these inactivators are present in detergent residue – discussed in more depth on the next page. Thus, it is important that surfaces be rinsed prior to disinfection.

14.8.3

Detergent/disinfectant interaction

Due to the presence of anionic surfactants in many detergents, it is important to ensure that all residue is removed prior to the application of disinfectant solutions. Failure to remove these residues will allow a cross-reaction to take place between the surfactant in the disinfectant and that in the detergent leading to an inactivation of the former.

14.9 CHOOSING THE RIGHT DISINFECTANT The following factors should be taken into account when choosing a disinfectant:

r r r r r r r r r r r

Type of cleaning equipment Water hardness Contact time available Stability Microorganisms to be destroyed Type of surfaces to be disinfected Risk of food taint Application temperature Toxicity of disinfectant and effect on personnel Ionic nature of detergent used before disinfection Disinfectant method of application

14.10

WHERE TO DISINFECT

Disinfection is not applicable to all surfaces in a food-manufacturing environment and should only be used on those surfaces where the presence of significant numbers of microorganisms will have an adverse effect on the safety and quality of the food handled. If disinfection is deemed to be necessary then the following areas should be considered:

r r r r r r

Food contact surfaces Hand contact surfaces Post-process can handling equipment, conveyors and tracks Cleaning materials and equipment Hands Drains and floors

Cleaning and disinfection in the fish canning industry

14.10.1

275

Biological factors

The microbiological load can affect disinfectant activity. Also, the type of microorganism present is important. Spores are more resistant than vegetative cells. Certain disinfectants are more active against gram-positive than gram-negative microorganisms, and vice versa. Disinfectants also vary in their effectiveness against yeasts, moulds, fungi and viruses.

14.11 TYPES OF DISINFECTANTS Chemical disinfectants are defined by their mode of action and are split into two groups: oxidising and non-oxidising. Oxidising disinfectants such as sodium hypochlorite, peracetic acid and hydrogen peroxide attack all cell material and stop the cell functioning. Non-oxidising disinfectants such as QACs, Biguanides and Amphoterics are more subtle in their operation. They penetrate the cell wall and disturb the phospholid molecules, which make up the cell membrane, causing it to leak vital chemicals.

14.12 OXIDISING DISINFECTANTS 14.12.1

Sodium hypochlorite

Sodium hypochlorite is one of the most powerful disinfectant out of all the types of chemical disinfectants available. Its main advantages are that it is very effective against all types of bacteria (including spores), inexpensive in comparison to other disinfectants and is unaffected by hard water. For industrial use it will usually be supplied at 14–15% available chlorine (Av. Cl.). For domestic use it will be manufactured to give approximately 5% Av. Cl. and thickened with surfactants to provide good dirt penetration and prolong contact time. These 5% products are usually called Bleach. Sodium hypochlorite is very effective even at low concentrations. A 0.1% solution will give 150 ppm Av. Cl., usually enough for disinfection of clean food contact surfaces. Because sodium hypochlorite has a very strong smell, even at low concentrations, it should not be left on food contact surfaces and should be rinsed off after its recommended contact time, usually 15–20 minutes. It will also attack soft metals such as zinc, tin and aluminium, so care should be taken before deciding on its use. At temperatures above 50◦ C sodium hypochlorite will cause pitting corrosion on stainless steel. Care should also be taken in storage and stock rotation. The product will naturally lose Av. Cl. and should generally be used within 3 months of manufacture. If stored in direct sunlight the rate of loss of Av. Cl. increases. It should also be stored separate from other chemicals, particularly acids, as lethal chlorine gas will be released if these two products are mixed. Ideally sodium hypochlorite should be automatically dosed via a recommended dosing unit to ensure that it is used at the correct strength. Sodium hypochlorite may also be used for salad, vegetable or fruit washing but will usually be used in conjunction with an acid to reduce the pH level down to approximately 6.5. Because this process involves mixing chlorine and acid it needs to be rigorously controlled as overdosing of the

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acid may liberate chlorine gas. The installation of accurate, automatic-dosing pumps is usually the method employed.

14.12.2

Other chlorine donors

Another way of achieving disinfection using chlorine is in a concentrated tablet form. Typically, they consist of 55% dichloroisocyanurate, which is an organic chlorine donor, giving approximately 33% Av. Cl. These are dissolved in water, ideally at 40◦ C, and one tablet may typically give 200 ppm Av. Cl. in 5 litres of water. The tablets provide a safer and more reliable method of making up an effective working solution. A made-up solution will have a pH of typically 6.5. As mentioned this is the ideal pH for maximum efficacy. When used for salad, vegetable and fruit washing they do not require the addition of an acid to reduce the pH. They also have up to a 2-year shelf-life if stored correctly.

14.12.3

Hydrogen peroxide

Hydrogen peroxide works in the same manner as sodium hypochlorite but may not be as effective against as many microorganisms. It is used predominantly in the beverage and brewing sectors, as it is low foaming and ideal for CIP systems. Typically, a 0.03% solution will give 100 ppm hydrogen peroxide and at this level of concentration it may not require rinsing from the surface. Used at elevated temperatures it becomes more effective but less effective at ambient or lowest temperature. It is not safe to use on aluminium, zinc, tin or their alloys.

14.12.4

Peracetic acid

These products are used mainly in the beverage and brewing sectors as they are low foaming, effective against all types of bacteria and can be used at very low concentrations and temperatures. Two types of product are available, a 5% and a 15% activity peracetic acid. Used at the recommended concentration (e.g. 0.1–0.4% of a 5% active product will give 50–200 ppm peracetic acid) it would not typically be rinsed off. It will slowly decompose to acetic acid, oxygen and water. As with other oxidising disinfectants it should not be used on soft metals. Some peracetic acid formulations are approved by DEFRA for use against specific animal diseases.

14.12.5

Iodophors

Iodophors are expensive but very effective disinfectants having both detergent and disinfectant properties making them ideal for CIP use. They are produced by dissolving iodine in an acid medium together with surfactants. Advantages include the ability to kill a wide range of organisms, effectiveness at low temperatures, the ability to cope with soiling/hard water and requiring a short contact time. However they can cause taint if left on a surface without rinsing, even at the correct concentration. They may also turn some plastics brown and should not be used on soft metals. They are very rarely used in food manufacturing.

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14.13 NON-OXIDISING DISINFECTANTS Generally these disinfectants work through a number of mechanisms:

r r r r

Absorption onto the cell wall leading to increased permeability resulting in cell leakage; Withdrawal of calcium salts from the cell wall; Interruption of cellular respiration in the mitochondria leading to a reduction in the production of ATP; and Interruption of the cellular nutrient and waste transport mechanisms.

14.13.1

Quaternary Ammonium Compounds (QACs or Quats)

QACs are the most widely used biocides in the food-processing industry and are very effective against gram-positive bacteria but less effective against gram-negative bacteria, spores, moulds and fungi. In a properly formulated disinfectant this obstacle can be overcome. QAC-based disinfectants are stable and taint free. They may be inactivated by hard water, organic material and some plastics. QACs are not as effective against gram negative bacteria. This is thought to be due to the positive charge on the molecule making it hard to penetrate the outer wall of these bacteria. However, with the addition of sequestrants the disinfectants efficacy improves greatly. A good quality QAC terminal disinfectant will have passed the following tests: • BS EN 1276: 1997 • BS EN 1650: 1997 • TES-S-004

Bactericidal action at 10◦ C Fungicidal action at 20◦ C Triangle test for potential taint due to contact with materials

They are usually safe to use on soft metals at the recommended concentration, which is usually 1%.

14.13.2

Amphoterics

Amphoterics are excellent disinfectants but can be expensive. They have low toxicity, relatively non-corrosive, tasteless, odourless and are used at approximately 1%. They are high foaming and are unsuitable for use with machines and high velocity sprays.

14.13.3

Biguanides

These are cationic bactericides similar in function to QACs. They have no wetting properties and are therefore compounded with non-ionic detergents. Their main use within the food industry revolves around the disinfection of evaporator units. These types of disinfectants are formulated to provide a tenacious gel film when they come into contact with moisture. This gel then slowly releases the biocide and detergent. The introduction of these products has helped to ensure that the units only need to be stripped and cleaned on a 3 or 6 monthly basis, providing the treatment program is adhered to (spraying the internal components of the evaporator on a 3–4 weekly basis).

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14.13.4

Alcohols

Where there is a requirement for light cleaning and disinfection in an essentially ‘dry’ area, such as a bakery, then the use of an alcohol-based spray/wipe product becomes very useful. This is typically a blend of alcohol, QAC and possibly mild detergent additives, formulated to provide good disinfection in lightly soiled conditions therefore reducing the amount of water used. The product flashes dry after application thus removing the need for an undesirable wipe-dry operation.

14.14

EFFECTS OF TIME AND CONCENTRATION

Contact time and concentration are two of the most vital factors that can affect the performance of a terminal disinfectant. Although some disinfectants are effective within 5 minutes, in most cases it is recommended that they receive at least 15–20 minutes contact time (see Table 14.1). Failure to allow the recommended contact time could result in an ineffective reduction of microorganisms on the disinfected surface. Disinfectants should always be used at the manufacturer’s recommended concentration and an even coverage of the surface is vital. Attention should be paid when applying disinfectants to horizontal surfaces after rinsing; the presence of pools of water will dilute the disinfectant solution. If a 1% solution of a QAC-based disinfectant is applied onto a very wet surface, it has been found in some cases to dilute it down to as low as 0.1%, rendering it ineffective. Therefore it is recommended that before applying disinfectants on horizontal surfaces they are wiped over with a clean cloth and conveyor belts are switched on to remove any excess water. As pointed out earlier, it is important to ensure that detergent, organic and inorganic residue are thoroughly rinsed from the surface before disinfection takes place. Any residue left could deactivate the disinfectant. Table 14.1

Disinfectant efficacy table.

Disinfectant type

Typical use concentration

Chlorine compounds Hydrogen peroxide Peracetic acid

50–500 ppm Av. Cl. 100–400 ppm

50–200 ppm PAA Iodophors 10–100 ppm QAC 1% Amphoterics 1% Biguanides 1% Alcohol/QAC 1% QAC 70% Alcohol *** Effective. ** Moderately * Partially

effective. effective.

Type of microorganism

Recommended Typical contact time Gram pH (minutes) −ve

Gram +ve

Spores Yeast

Moulds

8–10

5–15

***

***

**

***

***

4–5

5–15

***

***

**

***

***

4–6

5–15

***

***

***

***

***

2–4 9–10 8–10 4–6 5–6

5–15 10–15 10–15 10–15 1–5

*** ** ** *** **

*** *** *** *** ***

*** * * * *

*** *** *** ** ***

*** * * ** *

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Anionic surfactants are negatively charged and are used in most foam and manual use detergents. Cationic surfactants are positively charged and are used in most disinfectants. The failure to rinse off the detergent with the negative charge will neutralise the disinfectant with the positive charge.

14.15 SPECIFIC ISSUES RELATING TO FISH CANNING OPERATIONS In an earlier section of this chapter reference was made to the suitability of chlorinated, alkaline foam detergents in the fish processing industry due to their ability to hydrolyse proteins and remove fatty deposits as well as the practicalities of application over a large area of processing equipment in a relatively short space of time. Care needs to be taken, however, to ensure that application to soft metals or galvanised surfaces is minimised to minimise the risk of equipment corrosion, In those operations which are of predominantly aluminium or galvanised steel construction a chlorinated inhibited product is often employed to provide a ‘barrier’ between the chemical and the metal surface whilst still achieving a satisfactory standard of cleaning. Of greatest concern in any canning operation, and in particular fish canning, is the effective cleaning and disinfection of post-process can handling areas/equipment in order to minimise the risks of microbial recontamination of the now commercially sterile can contents through inappropriate handling or seam-sipping. The risks associated with seam-sipping has been greatly reduced through the introduction of the two-piece can which lacks a side or base seam, however with the move to the ‘ring–pull’ style can, many of which have three seams, the issue still requires addressing and controlling to ensure food safety. The use of timed-dosing units on post-process can tracks and conveyors to dispense a mist of a taint-tested QAC-based disinfectant is recommended to ensure that the microbial flora remains under control. Methods of can cooling also need to be addressed and monitored to ensure bacterial build-up is not taking place, for example on ‘Alpine Runways’ or in the housing of air blowers. Handling of the cans post-process by operatives must be discouraged, however where this is unavoidable operatives should be provided with an alcohol-based hand disinfectant to reduce the level of resident or transient bacteria present on their hands.

14.16 CLEANING MANAGEMENT All food manufacturers should have a company hygiene policy and included within this should be provisions for an effective approach to the hygiene management system. The policy should make the following provisions:

r r r r r r r

A statement of commitment, at the highest level, that cleaning is essential for product integrity; State the responsibilities of directors, management and operatives; State the standards required by the manufacturer, customers, third-party auditors and legislation; Identify the resources that will be made available such as labour, equipment, chemicals, water; Systems for monitoring, controlling, improving the hygiene system, including documentation; Training of management and operatives; and A system of review.

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Table 14.2

Example only: cleaning program for processing area.

Frequency

Time

Type

Team

Daily Prior to product change Production breaks

14:00 to 18:00 10 minutes between products 22:00 to 22:30 02:00 to 02:30 06:00 to 06:30 10:00 to 10:30 18:00 to 14:00

Hygiene clean Interproduct clean Interproduct clean

Hygiene team Production Hygiene team

Clean and tidy of floor and waste

Hygiene team

Ongoing

14.17 CLEANING PROGRAMME The cleaning methodology and management controls must be appropriate to the process and the risks to the food.

14.17.1

Setting the standard

The first step for implementing a successful hygiene management system is to ensure that the standards required by the manufacturer, customers, third-party auditors and legislation are clearly identified, recorded and communicated to all employees. Example only: Standards required prior to start of production in pre-process areas:

r r

Visually clean and free from debris Food contact surfaces – total viable count < 103 CFU/cm2

14.17.2

Developing cleaning methodology

The cleaning methods need to be developed and trialled to see if they meet the standards required. Competent and trained hygiene management together with third-party consultants, such as reputable chemical suppliers, using the risk assessment approach should define the frequency and devise the methodology of cleaning for each area of the process. The cleaning process then needs to be risk-assessed to see if any direct or cross-contamination issues occur by utilising the methodology. It is useful at this stage to summarise the cleaning programme (as shown in Table 14.2). The cleaning programme should be validated to ensure that it meets the standards set. Once validated the methodology can then be recorded as the cleaning schedule.

14.17.3

Design of verification programme

The verification process is part of the design and review of cleaning methodology. The process is used to validate a proposed cleaning methodology and then as part of the management review to monitor performance against standards. This then enables development of the process in the drive for continuous improvement. Microbiological testing, ATP monitoring or protein testing can be used for a number of purposes, however, we are specifically considering their use for the verification of cleaning. Samples can be taken (sampled) from environmental surfaces; these include food contact surfaces such as the cutting blades, indirect food contact surfaces such as the control panel for a conveyor

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and non–food contact surfaces such as the framework of a conveyor. Any sample taken will as the name suggests only be a sample and cannot reflect all surfaces that the food will come into contact with in production. As such the sample sites need to be chosen to best reflect the effectiveness of the clean. Process samples can be taken from the equipment as another measure of the cleanliness of the equipment and therefore the effectiveness of the clean. These can be:

r r

Product samples: These are taken as first-off products from a line. As such these first-off products will have contacted all food contact surfaces. Process water samples: These are collected to ensure that any biocide being added to the can cooling water (either in batch or in continuous process cookers) remains effective and within the required concentration parameters.

14.17.4

Create cleaning schedule documentation

It is the responsibility of the food manufacturer to document the cleaning procedures; however, the chemical supplier may assist with the process. The purpose of the documentation is:

r r r

For training of hygiene/production operatives; As a reference for hygiene/production operatives; and To enable auditing of the process.

The documentation can be very extensive since it needs to cover a number of different types of clean, the detail of cleaning and any controls required as defined by the risk assessment process.

14.17.5

Training

Training of management and operatives is important to ensure that staff carry out their duties correctly and fulfil their potential by understanding:

r r

Their responsibilities within the team; and The standards required.

With good training confidence is promoted, job satisfaction increased, team spirit developed, performance improved and the amount of supervision required reduced. Those companies that invest in the time and resources for training tend to reap the rewards of increased profitability. Training should be tested and recorded.

14.17.6

Control of cleaning

It is important to monitor the energies that are used for cleaning to ensure that they are in line with those established when the methodology was validated. A record should be kept of the factors and if any are out of specification corrective action must be followed to restore to that defined in the methodology.

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For open plant cleaning this would involve:

r r r r

Checking that the physical strip down of equipment meets that defined on the schedule. Checking the chemical strengths of detergent and disinfectant as applied to surfaces. This will generally involve a simple test kit. Checking the strength of disinfectants on surfaces after application to ensure that no dilution or inactivation is occurring. This can be carried out using disinfectant-specific test strips. Checking the water temperature and pressure of any washdown system. Water temperature and pressure are often critical to achieving a successful clean.

14.17.7

Audit of cleaning

Visual inspections after the cleaning process are important to ensure that the required visual standards are achieved and maintained. The inspection should be thorough and all areas should be covered including those outside the daily cleaning program. Inspections after the cleaning process should make provisions for pass, caution or recleans. The results of any inspection (positive or negative) should be firmly communicated to relevant members of staff with a corrective action loop in place. Where specific testing such as micro testing of a product and the environment is required, it is important to have a sampling plan in place so that clear trends can be built up and any problems identified and actioned.

14.17.8

Review

As with any system it is important to build in a review procedure. The hygiene system should be reviewed on a regular, continuous basis but no less than annually. In addition a review must be carried out if there is a change in the process or products.

REFERENCES Curiel, G.J., Hauser, G., Peschel, P., and Timperley, D.A. (1993) Hygienic Design of Closed Equipment for the Processing of Liquid Food; EHEDG Report; Published by Campden BRI and Chorleywood Food Research. Holah, J.T., Taylor, J.H. and Holder, J.S. (1993) The Spread of Listeria by Cleaning Systems, Part II. Technical Memorandum 673. Campden BRI, Glos. Holah, J.T., Middleton, K.E. and Smith, D.L. (2004) Cleaning Issues in Dry Production Environment, R&D Report 192. Campden BRI, Glos.

15

The canning factory

Les Bratt

15.1 THE FISH CANNING FACTORY: INTRODUCTION The canning factory provides the vital facility in the production of foods that are safe for the consumer, that are legally compliant and that are of consistent specified quality. Essentially the factory should be designed, constructed, maintained and operated to provide a protective environment for the manufacture of the company’s canned fish products. It provides the processing areas in which the necessary machines are positioned and in which the employees work but also provides storage space for both raw materials and finished products, and numerous facilities concerned with the hygiene, well-being and safety of all personnel who work in the factory. More recently the question of site security has assumed greater importance. Historically companies have always been concerned to protect their premises against theft of materials or malicious damage. In addition, there is now the concern that factories could be the target of bio-terrorists. This is of particular importance for companies wishing to export to the United States and it is now customary that companies are asked to provide evidence of the adequacy of their security arrangements. The general requirements for food factories, to be met by operating companies, are included within European Regulation (EC) No 852/2004 on the hygiene of foodstuffs and the relevant sections of both the International Food Standard and the standard of the British Retail Consortium.

15.2 SITE SELECTION The selection of the site for the cannery is of paramount importance. The company should employ risk analysis, in which the likelihood of potential hazards arising from the location is considered together with the seriousness of the resulting impact on food safety or quality. Initially it is important that there are no external factors that might offer a threat to food safety and lead to possible contamination of the products being manufactured. Such contamination might be caused by neighbouring industrial activity that produces airborne pollution, or by natural concerns such as the propensity of the area to flooding. With established factories it is appropriate that a periodic review takes place to ascertain whether there are any new risks associated with the external environment and if so what measures are necessary to minimise the effects of such risks. It is also important in planning the location of a cannery to consider the local availability of resources, in particular those of fish, empty cans and labour. If fresh fish are being processed it is clearly important that the time taken from the port to the factory is as short as possible if the fish are to be subsequently processed in optimal condition. Refrigerated transport is expensive and adds to the costs of manufacture. Depending on the size of the operation, cans may ideally be manufactured on-site, or may be available locally. It is expensive to ship empty cans, a situation eased to some extent by the availability of tapered

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cans that stack easily during transit and storage. The infrastructure of roads and shipping available for export of finished products is also an important consideration in the location of the factory. Fish canneries tend to be located in parts of the world where labour is relatively inexpensive and available. If it is necessary to import and house foreign workers then clearly there are costs and administrative burdens associated with such activity. If local labour is relatively expensive as in the case of European factories then the factory will need to be extensively mechanised and employ fewer people in consequence. The uninterrupted supply of services, in particular electricity and water, is also important. The canning of fish requires electricity for numerous control applications and failure of such control can have serious implications for product safety. Canneries may have standby generators, the operation of which tends to be expensive, but it is clearly preferable that the municipal supply remains unbroken. The quality of water supply is considered in detail later in this chapter but the microbiological quality whether from the town supply or from the factory bore holes is of crucial importance in both product make-up and can cooling. Canneries also use vast amounts of water and with increasing environmental concerns the need for suitable effluent systems has become ever more important. Modern effluent plants are available that provide for some recycling of water and in doing so reduce the total amount of water discharged from the factory.

15.3 FACTORY DESIGN AND CONSTRUCTION The canning factory must be structurally safe and must be designed and built in accordance with the relevant local and international building regulations. This will require input from suitably qualified architects, project managers and trades people but of equal importance is the input of those persons who understand the processes to be employed and the necessary considerations for the hygienic production of canned fish products. This is particularly true in understanding the manner of access to the factory and the hygienic arrangements necessary for all employees, the required separation of certain processes, the hygienic nature of surfaces to facilitate cleaning, the means for waste removal and the temperature controlled storage of raw materials. It is important that the building structures by nature of their design do not contribute to any risk of contamination to the products being manufactured. During the building process frequent review meetings should be held to ensure that all design considerations are still relevant and are being met.

15.3.1

Exterior considerations

Apart from the manufacturing building itself it is also important to consider the overall site. Considerations of site security in having controlled access to personnel and vehicles must be addressed. It is necessary to have knowledge of all the persons present on the site and that they are there with the approved knowledge of the company. Roadways and hard standings should be of sufficient size and strength for the commercial vehicles likely to enter the site. The entry and exit of vehicles should be monitored and controlled and there will be a requirement for a weighbridge for commercial vehicles entering and leaving the site. Parking facilities will be required as necessary for employees and visitors with motor vehicles. They should be ideally positioned away from factory buildings so as not to interfere in any way with the passage of industrial vehicles involved in company operations. The site should be designed and maintained in such a manner so as to minimise any harbourage for pests. Areas against the factory walls should be clean and uncluttered and planted areas if present at all should be suitably distant from the buildings and well maintained. The outer facings

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of the walls should be designed and finished so as to deny ingress to pests. If external storage of materials is for any reason necessary then the materials themselves should be adequately protected and should not compromise the overall hygienic integrity of the site. The factory must be protected from flooding and drainage across the site should be adequate, particularly in regions subject to heavy tropical rainfall. In certain areas with limited rainfall, rain may be collected to supplement the water supply. Waste materials, including fish offals and effluent water, will inevitably be produced during processing operations and mechanisms must be in place for the organised removal of such materials from manufacturing areas and for their subsequent disposal. Clearly such arrangements must not represent any risk of contamination to the ongoing factory operations.

15.3.2 The factory layout: general considerations The canning of fish products comprises a number of consecutive operations. Ideally the process flow through the factory should be linear so that processed material cannot be physically or microbiologically recontaminated by unprocessed material. The layout of the factory is of paramount importance in the realisation of three major considerations in the attainment of safe food of specified quality:

r r r

Filling of uncontaminated product of specified quality into cans; Positive identification between unsterilised and sterilised cans; and Prevention of post-process contamination immediately after sterilisation.

Fish requires preparation prior to filling into the containers in which it is to be sterilised. Such operations involve the removal of materials including skin, heads, tails and guts, and may be accomplished manually or by machine. It is important that the operations are so organised so that waste material is effectively removed and cannot further contaminate the fish that is to be subsequently processed and filled. In the preparation of pre-cooked tuna in particular, it is recommended that the initial operations of head and tail removal are physically separated from subsequent cleaning of the tuna loins. This latter operation is labour-intensive and time-consuming. Increasingly it is undertaken in an air-conditioned environment of about 22◦ C providing a more pleasant working environment for the employees and also reducing the likelihood of pre-process microbial deterioration of the fish material. Working space should also be adequate for the operations being carried out particularly in labour-intensive situations. Overcrowding greatly increases the chances of error, in sorting or cleaning operations, and could lead to inadvertent product contamination. In the initial design of the factory it is necessary to give proper consideration to the possibility of future expansion and the commensurate size of processing areas required. It is virtually impossible simply by looking at a can to know whether it has been sterilised or not. Consequently procedures must be in place and the factory layout so organised so as to ensure that all cans that are filled and seamed are subsequently sterilised. Mechanisms for ensuring such identification and separation include:

r r

The use of heat-sensitive labels attached to retort crates that change colour when subjected to heat process. The use of heat-sensitive ink for ink jet coding of cans that change colour when subjected to heat process.

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A defined marshalling area for the accumulation of crates of unprocessed cans prior to loading into retorts (essential in the case of batch retorts fitted with only one door). Batch retorts fitted with two doors. Physical barriers should be fitted that prevent the passage of crates of unsterilised cans into the post-retort area. A one-way gate then allows the return of empty crates to the crate filling area. The provision of a post-process holding area in which crates of cans are located and allowed to cool and dry before onwards processing. The use of fully automatic batch retorts in which crates of cans are filled and automatically loaded into retorts, sterilised and automatically unloaded. The process of reconciliation of cans filled and seamed with cans that have been sterilised.

Immediately after sterilisation and removal from the retort, cans are still warm and wet. The sealing compound inside the double seams is soft and there is the possibility of post-process infection which could involve pathogenic microorganisms. For post-process infection to occur three factors are necessary: a source of infection, which could be an employee’s hands; a fault in the double seam, which could be due to temporary deformation and water which provides the possibility for microbial movement across the double seam. Once cans are dry and cool, the possibility of post-process infection has been removed. For this reason in the case of batch retorts it is vital that a post-process holding area is provided in which cans are allowed to cool and dry before onwards processing to palletisation or labelling. The area should have restricted entry and hand sanitising gel should be available to those employees charged with moving crates into and out of the post-process area.

15.3.3

Walls, floors and ceilings

Walls Interior walls of a factory may be the inner surfaces of the outer walls or may be internally constructed walls for the division of the factory into different operational areas. Such division not only provides the necessary separation of different processes but also provides security, thermal and acoustic barriers, and such walls may act as anchor points for the attachment of items of equipment. Clearly walls are required to have the structural integrity for which they are intended and may be load bearing or merely partition dividers. Qualified design is required in ensuring that structural requirements are suitably met. Hollow walls should in general not be used because the inner voids may inevitably provide harbourage for pests. The Regulation 852/2004 of the European Union requires that ‘wall surfaces are to be maintained in a sound condition and be easy to clean and, where necessary, to disinfect. This will require the use of impervious, non absorbent, washable and non-toxic materials and require a smooth surface up to a height appropriate for the operations unless food business operators can satisfy the competent authority that other materials used are appropriate’. Similarly the BRC Global Standard for Food Safety Issue 5 requires that ‘Walls shall be designed, constructed, finished and maintained to prevent the accumulation of dirt, minimise condensation and mould growth, and facilitate cleaning’. The choice of surface coating of walls to meet the listed objectives falls between various forms of specialised epoxy or polyurethane paints, composite panels, cladding materials that are attached as sheets to the walls and ceramic tiles. Just as important as the choice of coating is the selection of contractors who are competent in their application. Paint systems require time to cure and may provide a taint hazard for a few days after application. Cladding materials have the advantage of

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providing heat insulation and this may be important in areas where air conditioning is to be applied. It is preferable that the cladding is an integral part of the wall structure but if cladding sheets are used any voids between the wall surface and the sheet should be filled in order to eliminate the possibility of pest infestation and/or mould growth. Composite panels were originally developed for cold store use but have become generally acceptable as providing a hygienic option for foodprocessing areas. The panels are of sandwich construction with skins formed from a plastic material or glass reinforced plastic. The composition of the panel including the thickness of the various layers will determine the properties for heat and sound insulation. However, fires within a number of food factories have indicated the potential drawbacks inherent in such systems. The central core is often made from polystyrene material, which melts at about 80◦ C and then flows causing a self-generating effect in a fire which is almost impossible to extinguish. Special consideration should therefore be given to the fire rating for such panels. Ceramic tiles may be useful in areas that are subject to frequent washdown. They should be of suitable specifications. Standards for the chemical and water resistance of ceramic tiles are given in ISO 10545:1997. They should be fixed with sufficient adhesive so that there are no voids behind them and the grouting used should be light-coloured epoxy resin material. The fixing and grouting materials used should conform to the performance requirements given in EN 12004:2001. Tiles do have the advantage that if one tile is damaged it is relatively easy to replace. The junction between the wall and the floor should be coved to provide ease of cleaning and it is also advisable to protect the wall from physical damage by the installation of a stainless steel crash rail some 250 mm in front of the wall and 250 mm above the floor.

Floors The floor is one of the most critical components of a factory for it is on this that all major items of machinery are positioned and all operations take place. Any disruption to the floor may have significant and expensive consequences for the company and so it is necessary that all efforts are made to ensure that the floors are suitably established in the first instance. The floor represents a very significant financial investment and it is vital that floors are designed and laid by contractors who have demonstrated competence in this area of construction. The properties required of the floor, depending on the type of area, include structural strength, water and chemical resistance, fat resistance, drainage, cleanability and some element of anti-slip finish as appropriate to protect the health and safety of employees. Certain areas of fish canneries include inherently wet operations, such as defrosting. Whilst every attempt should be made to limit the amount of water that is allowed to flow generally over the floor surface it is inevitable that certain floors will become wet, including during washdown and cleaning operations, and the floors must be designed accordingly. In a similar manner to the statement on walls, the Regulation (EC) No. 852/2004 states that ‘floor surfaces are to be maintained in a sound condition and be easy to clean and, where necessary, to disinfect. This will require the use of impervious, non-absorbent, washable and non-toxic materials unless food business operators can satisfy the competent authority that other materials used are appropriate’. The BRC Global Standard for Food Safety, Issue 5, has a number of prescriptive requirements for floors specified in three paragraphs: Floors shall be designed to meet the demands of the process, and withstand cleaning materials and methods. They shall be impervious and maintained in good repair. Drainage, including drains from laboratories, where provided, shall be sited, designed and maintained to minimise the risk of product contamination and not compromise product safety.

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Machinery and piping shall be arranged so that, wherever feasible, process water goes directly to drain. Where significant amounts of water are used, or direct piping to drain is not feasible, floors shall have adequate falls to cope with the flow of any water or effluent towards suitable drainage. It is a simplification to think of the floor simply as the topping layer. In reality the floor structure as a whole comprises a number of layers and deficiencies in any of these may cause problems to the immediately visible topping layer. The layers comprise the following: Structural floor slab: This is the substrate necessary to withstand all mechanical and thermal stresses that are likely to occur during the operations of the factory. It must remain stable in order to protect the upper layers of the floor structure including the ultimate surface used as topping. Membranes: Canning operations, particularly in certain areas such as those used for the thawing and preparation of fish, tend to be wet in nature. A good floor design requires that there is a waterproof and chemical proof membrane to protect the structural slab from damage due to porosity of concrete that in turn could cause deterioration of the floor as a whole. The design and siting of the membrane is important and needs to be considered as part of the early design process because it will have to allow for drainage gullies and other services that are to be included in the floor. Screed: It may be necessary to apply a screed layer to the structural slab in order to provide a smooth surface prior to application of the topping. The screed material is normally made from fine concrete or cement mixed with fine aggregate, and it may be bonded, or not, to the base. Screed should be laid in as large an area at one time as possible in order to minimise the possibility of curling. Movement joints: Temperature changes, shrinkage due to drying, moisture absorption, distortion due to mechanical load are all factors that may all result in movement of the floor and potential damage to the upper surface such as loss of adhesion, cracking or bulging. Such problems are obviated by the introduction of movement joints. All movement joints in the sub-floor must be continued through the surface flooring whether it is made from synthetic resin or tiles. Drainage: Drainage is a most important consideration in the design of the factory and should be spatially organised as far as possible in view of the planned deployment of processing equipment. There are two aspects: the positioning of the drainage gullies relative to the machinery and the fall of the floors so that surface water readily enters the gullies. The siting of the drainage gullies should be adjacent to the relevant machines (but not underneath and consequently difficult to access). The slope of the floor should be normally about 1 in 60 towards the drains, but this will vary according to the texture of the surface of the floor and the volumes of water likely to be encountered. The floor surface: There are essentially three options for the upper surface or topping of the floor, concrete, ceramic tiles or a resin finish. Concrete is not considered ideal in food-processing applications. It is resistant to chemical attack from alkalis, mineral oils and many salts but is attacked by acids, vegetable and animal oils, sugar solutions and by some salts. In addition, concrete is liable to crumble when subject to mechanical impact or abrasion. Plain concrete may be improved however by the addition of polymer to the mix that provides better performance under compression or flexing, improves resistance to liquid penetrations and provides a surface free from dusting. Ceramic tiles are available with a range of non-slip surfaces and provide a durable and hygienic flooring material. However they must be laid by suitably skilled craftsmen and must be properly grouted to form an impervious surface. One advantage of ceramic tiles is that individually damaged tiles may be conveniently repaired.

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Resin floors are made from various materials, for example epoxy, polyurethane, polyester or methacrylate and provide a seamless hygienic surface with the option of the addition of varying degrees of non-slip component as required. The success of a resin floor also depends on the skill of the contractors and on the quality of the underfloor structure. A detailed review of the requirements for factory floors is provided in Campden BRI Guideline No. 40, ‘Guidelines for the Design and Construction of Floors for Food production Areas’ and further details on the properties of resin floors are given in the ‘Guide to the Specification and Application of Synthetic Resin Flooring’ available from the website of FeRFA, Resin Flooring Association, www.ferfa.org.uk.

Ceilings In the design of the factory it is necessary that the overhead structures do not accumulate dirt and condensation that could subsequently drop onto and contaminate open food below. They should not provide harbourage for roosting of birds and other pests. Consideration should also be given to the ease of cleaning of ceilings or roof supports. Suspended ceilings made from materials such as isothermal panels may be considered suitable in providing a clean unbroken surface above foodprocessing areas but access must also be made available to the voids above in order to inspect for any pest activity, the maintenance of utility service arrangements and for cleaning.

15.3.4

Windows and lighting

Glass is a hazardous material to be deployed in food-processing areas. It is a brittle material and contamination of food material with broken glass fragments could have serious consequences for the consumer and subsequently for the manufacturer. Glass however is the traditional material for the manufacture of windows. The use of glass must therefore be carefully considered. Are windows actually necessary in areas where open food is in preparation? If windows are required, either in the construction of internal offices or within external walls, then they should preferably be made from plastic materials, toughened glass or protected by the application of plastic film that will prevent shattering in the event of breakage. Similar considerations apply to lighting. Clearly it is necessary that sufficient lighting is provided to enable the tasks being carried out to be done so properly. This is particularly true in areas where preparative or sorting operations are taking place. It is equally important however that the light fittings themselves do not present any risk to the safety of the food being processed. The BRC Standard Issue 5 requires that ‘Where they constitute a risk to product, bulbs and strip lights, including those on electric fly-killer devices, shall be adequately protected. Where full protection cannot be provided, alternative management such as wire mesh screens, or monitoring procedures shall be in place’. All glass and brittle materials should be included within a register against which audits take place. The frequency of such audits should be assessed on the basis of risk. Items in areas where open food is present should be checked more frequently, perhaps daily, than areas such as finished product warehouses where materials are already protected by finished packaging.

15.4 THE PRINCIPAL AREAS OF THE FACTORY 15.4.1

Entrances to the factory

Having gained entry to the site it is then necessary that the manner of entry to the factory and to subsequent processing areas is suitably organised and controlled. The outer door to the factory

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should be easily opened and should be of adequate size relevant to the number of employees likely to be entering or leaving at any one time. The entrance of each individual should be recorded for safety and administrative reasons and the entrance should be protected when open to minimise the risk of the entry of pests. If plastic curtains are used to protect the open doorway they should be maintained in a good condition and should be sufficiently heavy so as not to be blown apart by the prevailing wind. Additional protection may be provided by the use of air curtains and the deployment of electric fly-killing machines. The entrance should lead directly to the male and female locker rooms and changing facilities and hence to the hand wash stations prior to entry to processing areas. Solid doorways between different processing areas should remain closed unless required for use and if it is considered necessary to restrict personnel to certain processing areas then operation of the doorways should be controlled by means such as security swipe cards or keypads. Entrances to office accommodation used by staff and visitors to the company should be monitored by reception staff in order to register the entry and exit of personnel and to prevent unauthorised access to processing areas.

15.4.2

Social facilities for employees, including changing rooms, toilet accommodation, hand washing and shower facilities and canteen

Ideally the entrance premises for operational staff should provide direct access to processing areas without the need to transit across external roads or yards. Changing facilities should be provided with individual lockers for keeping items of personal clothing and other items. Preferably the lockers should be of metal construction and have ventilation and sloping tops to prevent the accumulation of dust and personal items. Clean toilet accommodation must be provided. Units should be available both in the entrance facilities and in other appropriate areas relative to working locations. On no account may toilets open directly onto production areas and adjacent hand-washing facilities with soap and water at a suitable temperature and hand drying facilities must be provided. External protective clothing should be removed before entering toilets and facilities (hooks or hangers) are therefore required for the temporary storage of such clothing. Guidance to the number of toilets required depending upon the size of workforce is given in the Health and Safety Executive publication INDG293 of the UK Government. General hand-washing facilities prior to entry to processing areas (and elsewhere within the factory) are best fabricated from stainless steel and should have non-hand operated taps (automatic, knee or foot operated). Soap, water at a suitable temperature and hand-drying facilities (single-use towels or suitably designed air driers) should be provided. In certain areas, such as the post-process handling areas, hand sanitising gel should also be available. It is unacceptable that personnel should eat, drink or smoke in manufacturing areas. Smoking in particular has been the subject of considerable national legislation and clearly companies must abide by local regulations in the provision (or not) of smoking facilities. Rest and canteen facilities should be provided for use by employees at break times. If appropriate, there should be refrigerated storage for personal food items and hooks or hangars for protective clothing prior to entry to the canteen. If meals are provided, the catering arrangements should be subject to necessary control and inspection for hygienic operation (this may also be a local legislative requirement). If consumption of food is allowed in external ‘picnic areas’ then such areas should be properly defined and there should be satisfactory arrangements to ensure that no waste food is left for the attraction of pests.

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Warehousing for empty cans and other packaging items

All items of packaging are vital components in the manufacture of canned fish products. Warehousing should be such that stored materials are easily identifiable, properly protected against damage or contamination and easily obtainable when required. Packaging materials should be stacked against the walls of the warehouse to allow easy access for pest control technicians. If partly used packaging materials are returned to the warehouse, they should be suitably protected against damage or contamination.

15.4.4

Warehousing for ingredient materials

Apart from fish the company is likely to use vegetable oils, tomato paste, salt and minor ingredients used in the preparation of sources. As with packaging materials, warehousing should be provided such that ingredient materials are easily identifiable, suitably protected against damage or contamination and easily obtainable when required. There is also the further requirement to identify and isolate any allergen or GMO materials in order to minimise any risk of cross-contamination. Soya oil may have been sourced from GMO beans and if so it should be stored in separate tanks or drums. Specifically designated lines should then be used for transfer of such material to the filling machines. Ingredients containing allergen components should be stored in a designated location, preferably with some element of colour coding to aid identification and to emphasise the need for control of such materials.

15.4.5 Receipt dock for raw material including frozen and/or chilled storage facilities The exact situation will depend on whether the factory uses fresh and/or frozen fish, or both, and whether the frozen cold storage facility is remote or an integral part of the factory. If fresh fish is used, chilled storage at ≤4◦ C should be available for buffer storage of fish that is not to be used immediately in processing. The temperature of frozen storage will depend on the fish species being processed and the likely duration of storage. Long-term storage of a high fat fish such as mackerel for instance requires a temperature in the region of −30◦ C. During transfer across the loading dock into the factory care should be taken, by the use of air curtains or other means, to prevent ingress of pests into manufacturing areas. Temperatures of chilled or frozen storage facilities should be monitored and recorded and, particularly in the case of frozen storage, should be alarmed in case of deviation from set values.

15.4.6

Defrosting area where frozen fish are thawed to a suitable temperature for further processing

Defrosting of frozen fish, depending on the method used tends to be a very wet operation. With the increasing cost of water and environmental concerns, it is sensible to review the amount of water being used and also to engineer the factory to minimise the amount of water discharged and lost on the factory floor.

15.4.7

Initial preparation area for essentially wet operations such as de-skinning, cutting and filleting

Machines used for initial cutting operations of fish, and machines used for de-skinning, nobbing or filleting operations vary in their design and complexity. However, in operation they all tend to use

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significant amounts of water. In the design and operation of the factory, thought should be given to minimising the amount of water that is discharged onto the factory floor and the positioning of drainage so that any such discharge is kept within the confines of the machines. Low bund walls underneath the machines may help in localising discharged water. Waste fish materials are also produced and it is important that these are accumulated and rapidly removed from processing areas to interim storage before final removal for fishmeal production. Such process of waste removal from the processing area may be carried out automatically or may require manual input.

15.4.8

Secondary preparation area in which fish is finally cleaned and sorted prior to filling into cans

This is likely to be the most labour-intensive part of any fish cannery, particularly the loin cleaning operations in a tuna cannery, the manual preparation of skinless and boneless sardines or the filling of fish into cans in a sardine factory. Sufficient space must be provided in which each worker is allowed to work and equipment should be designed and procedures organised to allow good separation between processed fish and waste materials. Identification of lots of fish should be maintained both for traceability purposes and to keep control of the delay times in processing and before retorting. As stated above, such areas are increasingly air-conditioned to about 22◦ C, which provides a more pleasant working environment and may limit pre-process microbial spoilage.

15.4.9

Pre-cooking area, in which fish such as sardines may already be placed in cans, or not, as in the case of tuna loins

Pre-cooking may occur in the process flow at various times relative to fish cleaning operations, or as in the case of salmon canning or raw-pack tuna processing is not required at all. Pre-cooking may be undertaken in batch pre-cookers or in continuous plant. The cooking temperature is normally at about 98◦ C but cooking times will vary according to the size of the fish being processed. Certain precooking equipment includes the facility for cooking to a specified backbone temperature (typically 60–65◦ C) using temperature probes inserted into the fish. Pre-cooking equipment may also have the facility for initial cooling and subsequent cooling and particularly in the case of tuna, will normally be accomplished in some sort of intermittent-spray cooling chamber.

15.4.10

Preparation area for sauces or liquids to be filled on top of fish in the cans

Canned fish is conventionally covered with a liquid such as brine, vegetable oil, tomato sauce or other sauces. The ingredients used may contain GMO (most likely in the case of soya oil) or allergen components such as celery used in spice mixes for tomato sauce. Care must be taken in the organisation of the sauce kitchen and the procedures used to ensure that there is no crosscontamination between products that contain such intolerant materials and those that do not. In the case of oils prepared from GMO materials, separate pipelines should be used for delivery to the filling machines.

15.4.11

Filling area in which fish, salt and liquids (oil, brine, water or sauce) are added to the cans

It is unrealistic to metal-detect fish products that have been filled into steel cans. Hence it has become increasingly common to pass prepared tuna loins or flakes through a metal detector prior to

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loading into the infeed hopper of a can packing machine. (It should be noted that the metal detection of mackerel products filled into aluminium cans is successfully practised.) The liquid component may be filtered and in-line magnets may be used to capture any tramp ferrous metal. Liquid material is generally filled into cans, to overflowing, through a sparge pipe arrangement. The overflowing material should be filtered prior to return to the filling head. If the filling of fish into cans is carried out by machine as is generally the case for tuna, automatic check weighing machines may be used to confirm satisfactory weighing performance. Such operation however should also be monitored by manual check weighing as in the case for fish cans that are manually filled.

15.4.12

Double seaming area

The double seaming operation is one of the most critical processes in the preparation of safe canned food. Double seam specifications should be specified in consultation with the can supplier and seaming machines should be maintained and operated only by personnel who have received appropriate training. Seam dimensions should be subject to monitoring by quality department personnel at defined intervals. There should be a logbook for each seaming machine in which all incidents or engineering interventions are recorded and lubricants used should be suitably food graded. Cans should pass through washing machines after double seaming and before retorting. The washing of cans after retorting should be avoided wherever possible.

15.4.13

Crate loading and accumulation area

Crates are loaded either manually, with some degree of mechanisation, or automatically prior to loading into the retorts. It is important that the area for the accumulation of filled unprocessed crates is big enough to ensure that the crates are easily identified, sequentially processed and properly distinguished from crates containing sterilised cans. In many canneries the crate loading area is separated from the seaming machines by a ‘hole in the wall’ arrangement. There is no real reason for this unless it is an attempt to contain steam emitted during the venting of steam retorts in the retort area.

15.4.14

Retorting area

The retorting area in most fish canning factories comprises a number of batch retorts lying parallel to each other. Increasingly, retorts are microprocessor-controlled and there will be process programming and recording equipment attached to each individual retort or located in a central control room. Alternatively, semi-manual retorts are used requiring the manual operation of control valves particularly during the come-up and cooling phases of the retort cycle. Whatever the system, it is vital that the geometry of the retort area is arranged so that the operator can fully identify the cans to be retorted and the thermal process required, and has easy access to the instruments that define and record the process conditions. Automatic retort operating systems should include alarms in case of process deviations outside of set values. Within the retort area there should be one clock, or synchronised electronic clocks, which serve as the prime reference for time. Whether fully automatic or semi-automatic processing equipment is used it is important that a manual retort operator’s log sheet is maintained on which the major parameters of all retort operations are recorded. Retorts carry individual instrumentation for temperature and pressure. The supply steam pressure available from the boilers should also be indicated in the retort area. Overpressure retorts require relatively

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high available steam pressures for successful operation and simple saturated steam retorts have high steam demand during venting. The retort operator should know the steam pressure available.

15.4.15

Post-process holding area

As explained above, recently sterilised cans, while still warm and wet, may be susceptible to postprocess contamination and spoilage. If cans are allowed to air-dry naturally a dedicated area should be provided, with limited access, in which cans are allowed to cool and dry before onward transfer to palletisation or label and case. Hand sanitiser should be available on entry to the area for use by all personnel responsible for movement of crates of cans. Alternatively some form of forced air-drying may be used using either batch or continuous equipment. However, manual handling should be eliminated as far as possible and all conveying equipment regularly sanitised. The hygienic design of post-process can handling equipment is suitably described in Campden BRI Technical Manual No. 8.

15.4.16

Label and casing area

Processed cans are de-crated prior to palletisation for interim storage or for feeding directly to label and casing machinery. After such de-crating operation the empty crates should be returned to the crate filling area through a one-way gate that will not allow passage of crates in the reverse direction. Hand sanitising gel should be available for all employees working in the label and case area.

15.4.17

Warehousing for finished products

Warehousing should be organised such that pallets of products are fully identifiable on racking so that they may be selected for despatch on the basis of customer specification, in accordance with good stock rotation, and with full traceability information. The loading dock should provide weather protection during the loading process and vehicles or containers should be inspected for cleanliness and overall suitability. The racking in the warehouse should allow sufficient free space against the walls to allow for pest-control inspections and pest-control measures should be suitably deployed.

15.4.18

Laboratory

Laboratories are used for physical, chemical and microbiological testing of materials to confirm compliance with specification. The laboratory should be a secure facility and the design of the laboratory together with operating procedures should ensure that there is no risk to manufacturing operations from materials used in the laboratory or from the various liquid or gaseous effluents emanating from the laboratory. Care must be taken in the design of both ventilation and drainage systems. Particular care must also be taken in the disposal of any microbiological waste. The risks involved will clearly depend on the scope of work undertaken and increasingly it has become a common practice for on-site laboratories to undertake simple tasks with more complex analyses being contracted to external commercial laboratories accredited against the ISO 17025 standard. If pathogen testing is undertaken on-site, the facility used should be remote from the manufacturing site. Sensory testing should form a routine procedure in assessment of the finished product. This should be undertaken in a separate facility dedicated for the purpose and not in the general laboratory where poisonous chemicals materials may be present.

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Engineering stores and workshop

Planned preventive maintenance is important in ensuring that machinery remains capable of manufacturing products within specification and reducing the incidence of lost manufacturing time or the production of non-conforming product. It is vital however that engineering resources, including the workshop and engineering stores, are located and operated in a manner that do not present any risks to product safety. The BRC Global Standard for Food Safety, Issue 5, specifically requires that ‘Engineering Workshops shall be controlled to prevent contamination risks to the product, e.g. provision of swarf mats where workshops open directly into production areas’. Inevitably in any factory there will be redundant machinery that has been taken out of commission. Such equipment should either be removed from the site as soon as possible or storage space made available, away from production areas, in which the items may be stored neatly and so as not to provide harbourage for pests.

15.4.20

Lockable storage area for cleaning and other chemicals

All chemicals, whether used for cleaning and sanitation purposes or for pest control, are potential contaminants of food materials. Hence they must be stored and handled in a manner that will eliminate any such risk. Chemicals should be stored in locked accommodation remote from manufacturing operations and with limited accessibility to suitably trained and responsible employees.

15.4.21

Tank farm for vegetable oils

Vegetable oils may be supplied to the factory in drums or in the case of large operations will normally be supplied by road tankers direct into a tank farm. It is particularly important that if any oils used are from GMO sources, then they are stored in separate tanks reserved for the purpose and that separate pipework is used to deliver the oil to the filling heads in the factory production area. Tank farms should be surrounded by a bund wall in case of leakage in accordance with local regulations.

15.4.22

Area for the accumulation and subsequent disposal of waste materials

Increasingly factories are required to meet ever more stringent environmental regulations. Factories produce a number of waste streams. It is important that waste materials are rapidly separated from ongoing processed material, that suitably sized facilities are provided for on-site storage before prompt removal from the site, that waste materials are collected and used for recycling wherever possible and that attempts are made to minimise the amount of waste material produced within practical realities. Waste materials should not be stored in a manner that will attract pests, and skips and compactors should be closed or covered as far as possible.

15.4.23

Effluent treatment facility

Fish canneries produce large amounts of effluent water. While processes should be reviewed to examine the possibility of reducing such effluent as much as practically possible, an effluent treatment plant is necessary to upgrade the quality of effluent before final discharge into whatever final system is used and in accordance with local regulations. It is to be expected that local

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regulations will become more stringent in line with increased environmental considerations. For example, canneries operating in seaside locations that currently discharge untreated effluent directly into the sea may not be allowed to do so in the future. The parameters of importance include volume per tonne of finished product, BOD, COD, nitrogen, phosphate, suspended solids, and oil and grease. Many existing canneries currently use a series of anaerobic and aerobic ponds but the availability and cost of the large areas of land required tend to indicate that sophisticated on-site effluent plants available from a number of manufacturers will become the preferred option.

15.5 15.5.1

SERVICES Water

Water is likely to be used for a number of widely differing functions within a cannery from product preparation to floor cleaning and fire control. It may be that water used is sourced from a number of different sources, from the municipal supply, from company bore holes or in some cases recycled water may be used. The European legislation for defining the use of water in a factory is defined in Regulation 852/2004 on the Hygiene of Foodstuffs, and the European Drinking Water Directive 98/83/EC lays down the standards for potable water. In the Drinking Water Directive some 48 chemical and microbiological parameters are listed and the required annual frequency of testing for potable water is defined depending on the volume of water used. Whatever the source of water used it is required that only potable water is used in contact with or in the preparation of food products. Mains water supplied to the factory should be of potable quality and the supplying company should provide analytical data certifying such quality at the point of delivery. However it is also possible that in-plant contamination could occur and for this reason the company should undertake or commission analysis of water from relevant sampling points at appropriate frequencies. Microbiological analyses should include as a minimum those for total plate count at 22◦ C, coliforms and E. Coli. If bore hole water or water from other sources is used it is likely that it will be chlorinated on-site. The free residual chlorine content should be tested at the point where the water enters the distribution system, at least twice daily. Once an adequate dosing regime has been established the frequency of testing may be modified accordingly. When non-potable water is used, for example, for fire control or steam production, or other purposes, it is to circulate in a separate and identifiable system. The colour coding of water pipes containing differing qualities of water may be prescribed under local regulations. Non-potable water is not to connect with, or allow reflux into, potable water systems. Recycled water may be used in processing only if it conforms to the same standard as potable water, and ice which comes into direct contact with fish must be made from potable water and must be stored and handled in a manner that prevents it from contamination.

15.5.2

Water for can cooling purposes

The principal consideration for can cooling water is that it should be free from microorganisms that could give rise to post-process spoilage whilst the cans are still warm after sterilisation. As a rule the total aerobic plate count should be no more than 100 organisms per mL of water after incubation at 20–22◦ C for a minimum of 3 days. All cooling water should be from a potable source. In the Steriflow type of retort, in which cooling water is contained in a separate external circuit, various types of water including sea water may be used. It is important however that the integrity of the plates or tubes in the heat exchanger is suitably maintained and that no make-up water is allowed to

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enter the retort during the cooling phase. In normal practice cooling water is re-circulated through a cooling tower system and may be disinfected usually by chlorination, but UV treatment is also used. It should be noted however that once the treatment has taken place UV-treated water contains no residual properties of disinfection. If the re-circulated cooling water contains high levels of organic impurities then filtration and/or periodic draining of the system may become necessary to remove gross debris. The free residual chlorine in cooling water should be checked during the cooling phase of each retort cycle.

15.5.3

Steam

The quality of steam required depends on whether steam may be in direct contact with food materials. If so, as in the case of defrosting or pre-cooking, then the steam must be of culinary quality. Boiler feed water treatment chemicals must be suitable for direct food use, the materials of construction including seals and gaskets must be compatible with the steam and any de-scaling or cleaning solutions, and final steam filters which are capable of removing all particles above 5 µm should be used and fitted prior to any steam injection point. The sizing and number of steam boilers is important in terms of efficiency and will depend to a large extent on the number and types of retorts deployed. Traditional saturated steam retorts use great amounts of steam during the venting process, whereas overpressure machines such as the Barriquand Steriflow type require steam at considerably higher pressures. Boilers should be selected after detailed discussion with the suppliers of the retorting equipment. It is also important that there is visible indication within the retort area so that the operators are immediately aware that there is sufficient steam available for processing. Figure 15.1 shows a design study of the Silver Food Factory, supplied by kind permission of Arnauld G. Gilles, Architect, Casablanca, Morocco.

Fig. 15.1

A design study of the Silver Food Factory. (Image courtesy of Arnauld Gilles.)

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REFERENCES AND SUGGESTIONS FOR FURTHER READING Campden Guideline No. 39 (2003) Guidelines for the Hygienic Design, Construction and Layout of Food Processing Factories. Campden Guideline No. 40 (2002) Guidelines for the Construction of Floors for Food Production Areas, 2nd edition. Campden Guideline No. 41 (2003) Guidelines for the Design and Construction of Walls, Ceilings and Services for Food production Areas, 2nd edition. Campden Technical Manual No 8 (1985) Hygienic Design of Post Process Can Handling Equipment. Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption. Directive 2003/88/EC of the European Parliament and of the Council of 10 November 2003 as regards the indication of ingredients present in foodstuffs. EN 12004:2001 Adhesives for tiles. Definitions and Specifications. European Regulation (EC) No 852/2004 of the European Parliament and of the Council of the 29 April 2004 on the hygiene of foodstuffs. INDG293 Rev.1, Welfare at Work, Guidance for employers on welfare provision. UK Health and Safety Executive, 09/07. International Food Standard for auditing Retailer and Wholesaler Branded Food Products, Version 5, August 2007. ISO 10545–13:1995, Determination of chemical resistance of ceramic tiles. ISO/IEC 17025:2005, General Requirements for the Competence of Testing and Calibration Laboratories. The BRC Global Standard for Food Safety, Issue 5, January 2008.

Index

access to factories, 284, 289–90 additives, 24–5 air conditioning, 285, 292 air curtains, 141–2, 290 air infiltration into cold stores, 141, 144 allergens, 13, 45, 255, 285, 292 aluminium for can making, 158–9 Appertisation, 179–80 ASHRAE, 132, 135, 137–9 ASP (amnesic shellfish poisoning), 104 astaxanthin, 103 BADGE, BFDGE and NOGE, 22–4 best before, 14–15 biological hazards, 62 Bioterrorism Act of the United States, 46–7 border inspection posts, 2 BRC Global Standard for Food Safety Issue 5, 51, 92–4, 240, 283, 286, 287, 289, 295 Campden BRI guideline, 40, 289 technical manual, 8, 294 canning factory canteen, 290 ceilings, 289 changing facilities, 289 crate loading area, 293 crate marshalling area, 286 defrosting area, 291 design and construction, 284 drainage, 285, 288 exterior considerations, 284 factory layout, 59, 285 receipt dock, 291 retorting area, 293 roadways, 284 services, 284 site security, 249, 283, 284 warehousing, 291, 294 waste removal, 284 water supply, 284 windows and lighting, 289

cans for heat sterilised fish products, 151–76 aluminium for can making, 158 can and end design, 152–7 can dimensions, 155–6 can end making process, 164–7, 173 can manufacture, 157–64 double seaming, 174–6 easy-open ends, 165–7, 219 epoxy phenolic coatings, 170 market for seafood cans, 151 mechanical properties of cans and ends, 167–8 organic coatings, 169 peelable membrane ends, 167 printing and coating of cans and ends, 168–72 recycling of metal packaging, 159 side seam welding process, 161 steel used in can manufacture, 157–8 sulphur staining, 170–71 tapered cans, 153 three-piece cans, 153, 159–62 tin free steel (ECCS), 158, 162 tinplate, 158 two-piece cans, 153, 160, 162–4 capacity of cold stores, FAO nine factors, 143 certification schemes, 85–101 accreditation, 87 BRC global standards, 92–4 certification bodies, 86–7 certification overview, 86–8 Dutch HACCP code, 97–8 FMI (Food Marketing Institute), 95 GFSI (Global Food Safety Initiative), 90–93 HACCP, 88 IFS (International Food Standard), 92, 94–5 ISO 22000, 98–100 quality management systems, 88 retail brand shares, 89–90 SQF standards, 92, 95–7 CFIA (Canadian Food Inspection Agency), 35, 53, 221 chemical hazards, 62

300

Index

chemical spoilage, 221 chemical storage, 299 chlorination of water, 296 cleaning and disinfection, 262–82 alcohol-based hand disinfection, 279 audit of cleaning, 282 choice of detergent, 265 choice of disinfectant, 274–8 cleaning categories, 262–4 cleaning energies, 264–5 cleaning management, 279–82 contamination during cleaning, 266, 269–70 disinfectant efficacy table, 278 disinfection, 272–9 floor cleaning, 270–71 foam and gel cleaning, 267 manual cleaning, 267 quaternary ammonium compounds, 267, 277 sodium hypochlorite, 275–6 tray and rack washing machines, 271–2 verification of cleaning, 280 Clostridium botulinum, 33, 49, 221, 222–3 Code of Federal Regulations of the United States, 44–6 Codex Alimentarius, 51, 86, 88, 97 coding and case marking for Canada, 41 cold store design and operation, 132–50 air infiltration, 141, 144 bulk storage rooms, 142 cold store capacity, FAO nine factors, 143–4 cold store design, 140–43 energy consumption, 145 engineering specification, 143 enzymatic spoilage, 134, 135 dehydration/freezerburn, 136, 139, 142 frost heave, 141 frozen storage life definition, 133 glazing, 136–7 insulation of cold stores, 141 microbial spoilage, 134, 135, 145 packaging of frozen fish, 138–9 relative humidity in cold stores, 139 rigor changes, 134 specification of cold stores, 143 storage life, effect of freezing process, 135 storage life, effect of intrinsic/extrinsic factors, 135–40 storage life, effect of pre-freezing treatment, 133 storage life, effect of temperature fluctuation, 138 storage life table for frozen fish, 137

thawing of frozen fish, 145–9 thaw rigor, 149 commercial sterility, 32–3, 225–37, 255 cryogenic freezing, 135 decision tree, 65–7 defrosting of fish, 116–21, 145–9 defrosting area, 291 dehydration/freezerburn, 136, 139, 142 double seaming, 174–6, 293 body hook butting, 176 double seam dimensions, 175–6 double seam formation, 174–5 double seam specifications, 176 free space, 176 importance of seaming operations, 174 overlap, 176 seaming speeds, 174 seam length, 176 seam thickness, 176 tightness rating (wrinkle grading), 176 drainage (floor), 288 drainage (site), 285 Dutch HACCP code, 92, 97–8 easy-open ends, 165–7 effluent systems, 284, 295 EFKs (electronic fly-killing machines), 289, 290 engineering specification of cold stores, 143 engineering workshop, 295 enzymic spoilage, 134–5 facilities canteen, 290 changing facilities, 290 hand washing, 290 locker room, 290 fat content of fish, 114, 116 FDA, 43–4, 51, 102, 108, 208, 248 FeRFA resin Floor Association, 289 filleting, 122 Fish Inspection Act in Canada, 35–6 fish quality, 102–31 antibiotics, 113 caustic peeling, 124 chemical indicators of quality, 130 chilling and freezing, 108–11 ciguatera toxin, 105 defrosting frozen fish, 116–19 filleting, 122–3 fish species, 102–4

Index

heading, 121–3 histamine development, 107–8, 130 histamine limits, 108 ice, 110 pre-cooking, 127–9 preparation of fish, 121–9 rancidity development, 107 RSW (refrigerated sea water), 108, 114 salmon, 102–4, 112, 113 skinning, 123 smoking, 124–7 spoilage factors, 106–11 storage of fish, 114–16, 129 testing of fish, 111–14 traceability, 111 TVBN, 130 fish species used for canning, 103 floors ceramic tiles, 288 drainage, 288 resin floors, 288, 289 screeding, 288 structural slab, 288 FSIS (Food Safety and Inspection Service), 88 GAP/GHP/GMP, 85–6, 219 GFIS (Global Food Safety Initiative), 90–93 glass glass containers for heat sterilised fish products, 177, 191 register, 289 windows, 289 glazing of frozen fish, 136 GMOs, 291, 292 HACCP, 51–84, 88, 212, 223, 238, 241 biological hazards, 62 CCP determination, 64–7 chemical hazards, 62 Codex Alimentarius, 51 control measures, 63–4 corrective action plan, 69–70 critical limits, 67–8 decision tree, 66 Dutch HACCP code, 92, 97–8 flow diagram, 58–60 HACCP seven principles, 52 HACCP team, 55–7 hazard analysis, 61–4 intended product use, 58 ISO 22000, 51, 52, 54, 65, 74 legal requirements for Canada, 40

301

legal requirements for EU, 7 legal requirements for the United States, 48–9 operational pre-requisite programmes, 64, 67, 69 physical hazards, 62 pre-requisite programmes, 52–4 management commitment, 55–6 monitoring of CCPs, 68–9 product description, 57–8 record keeping, 63, 73–4 salmon control plan, 67 scope/terms of reference of HACCP study, 56 stages ×14 of HACCP study, 55 verification and validation, 70–72 websites related to HACCP, 77 hand sanitising gel, 286, 294 hand washing facilities, 290 heading, 121–2 Health Canada, 34–5 heat sensitive ink, 285 heat sensitive labels, 285 heat treatment legal requirements, 7 histamine, 10–11, 107–8, 130, 134, 218, 221, 244, 254–5 ice, 110 IIR, 132, 133, 135, 137, 148 importer requirements for Canada, 38–9 incubation testing, 220, 223 ingredient materials, 12–14, 24–5, 213, 219, 241–2, 291, 292 insulation materials in cold stores, 141 International Food Standard, 51, 94–5, 283, 240 ISO 17025, 252, 253, 294 ISO 22000, 51, 52, 54, 65, 74, 92, 101, 241 label and case area, 294 labelling, 11–20, 40–41 laboratory, 294, 251–61 accreditation and competence, 252, 260 AOAC methods, 253, 254 ATP, 257 chemical analyses, 254–5 container examination, 258–60 GLP, 252, 253 histamine testing, 254–5 incubation testing, 255, 257 laboratory design, 252–3 laboratory location, 252 laboratory log books, 253

302

Index

laboratory (cont.) microbiological testing, 255–60 new product development, 253 scope of laboratory operations, 251–2 sterility testing, 257–8 swab testing, 256–7 water analysis, 256 LACF (low acid canned foods), 32–4, 47–9 legislation for canned fish to North America, 32–50 definitions of LACF (low acid canned foods), 32–3 regulatory systems in Canada and the United States, 32, 34 legislative requirements for Canada CFIA (Canadian Food Inspection Agency), 32, 35–8 coding and case marking, 41 Facilities Inspection Manual (FIM), 42 Fish Inspection Act (FIA), 35–6 Fish Inspection Regulations (FIR), 36–7 Good Importing Practices (GIP), 42 HACCP and pre-requisite programmes, 40 Health Canada, 34–5 importers’ requirements, 38–9 labelling requirements, 40–41 laws and regulations in Canada prohibitions applying to canned fish, 37–8 registration of establishments, 40 thermal process requirements, 42 legislative requirements for the United States, 43–50 bioterrorism legislation, 46 Center for Food Safety and Applied Nutrition (CFSAN), 44 Code of Federal Regulations, 44 FDA, 33, 43–50 filing of scheduled processes, 47–8 food allergen labelling, 45 HACCP for seafood regulation, 48–9 imports and exports, 46 laws and regulations in the United States, 44–50 low-acid canned foods or LACFs regulations, 48 nutrition labelling, 45 ORA (Office of Regulatory Affairs), 44 records maintenance, 47 registration for Bioterrorism Act, 48 registration of manufacturing facilities, 47–8

legislation EU, 1–31 Acquis Communautaire, 1 additives, 24–5 allergen labelling, 13 BADGE, BFDGE and NOGE, 23–4 best before, 15 contaminants, 26 fishery products from outside the EU, 8–9 food contact materials, 22–4 general food law, 2–4 heavy metals, 27 histamine levels, 10–11 hygiene rules, 6–8 identification marking, 10 imports to the EU, 2 ingredient listing, 12–13 labelling rules, 11–20 legislation regulations and directives references, 29–31 Marine Stewardship Council, 20 microbiological criteria, 10 nutrition and health claims, 18–21 nutrition labelling, 16–18, 45 pesticides, 26 product specific controls, 4–6 quantitative ingredient declaration, 14 third countries approved for import into the EU, 9 weights and measures, 28–9 liquid filling, 292–3 locker rooms, 290 lot marking, 20–22 mackerel, 106, 114, 123, 124, 127, 132, 133, 135, 137, 218, 221, 223 Marine Stewardship Council, 20, 251 mercury, 104–5 metal detectors, 292–3 microbial spoilage, 134–5, 138, 218–24 factors relevant to risks of spoilage, 219 handling of wet containers, 222 microbiological examination of spoiled cans, 223–4, 257–60 microbial groups responsible for spoilage, 220–21 post-process handling of cans, 220 post-process spoilage, 222 pre-process spoilage, 197, 221 under-processing, 222 microbiological criteria for foodstuffs, 10 nutrition labelling and claims, 16–20

Index

packaging formats for heat sterilised fish products, 151–78 packaging of frozen fish, 138–40 panelling of cans, 181 pathogen testing, 294 peaking of cans, 181, 184, 188 pests, 284, 286, 287, 289, 290, 294, 295 physical hazards, 62 Pillsbury Company, HACCP, 51 plastic containers for heat sterilised fish products, 177 post-process holding area, 286, 294 post-process infection and spoilage, 286, 296 pre-requisite programmes, 52–4 process deviations, 215–17 quality department, 238–50 calibration, 242 cleaning and sanitation, 239–40 complaints, 243–4 crisis management, 243 documentation control, 241 legal compliance, 244, 248 management review, 244 non-conformance and corrective actions, 247–8 pest control, 240 quality control, 244–6 quality plan, 246 R&D, 249 recall and withdrawal, 242 release of product, 249 scope of quality related operations, 238–9 security, 249 specifications writing, 240 traceability, 242–3, 246 training, 247 vendor assurance, 241–2 rancidity, 106–7, 135 recall and withdrawal, 3–4 receipt dock, 291 record keeping, 73–4, 215, 241 records maintenance for the United States, 47 registration of establishments for export to Canada, 40 registration of establishments for export to the United States, 47 regulation EC 852/2004, 283, 286, 287, 296 retailer concentration, 89–90 retorting area, 293

303

retorting machinery, 179–209 cascading water retorts, 180, 190–92, 228, 230 continuous retorts, 194–5 cooker cooler, 194 engineering considerations of retorts, 195–7 full immersion retorts, 180, 184–6, 216, 228 hydrostatic sterilisers, 194 instrumentation of retorts, 199, 213–14 legal obligations for retort installation, 207–9 pilot retorts, 192–4 retort baskets, 200–203 retort surveys, 212, 229 saturated steam retorts, 180, 182–4, 228 size and capacity of retorts, 197–8 steam/air retorts, 180, 187–9, 228 utilities required for retorts, 203–7 water jets cleaning, 189 risk analysis, 283 RSW (refrigerated sea water)/brine freezing, 106, 114 salmon, 102–4, 112, 113, 132, 140, 153–6, 218, 220, 221, 223 farmed salmon, 113 salmon control plan, 67 salmon quality grades, 112 sanitising gel, 279, 286 sardines, 4–5, 106, 107, 132, 133, 153, 154, 218 scheduled heat process, 210 scombrotoxin, 130 Seafood Products Association, 67 sealing compound, 286 sensory testing, 294 services (factory), 284, 295, 297 shelf life of canned fish, 156 shelf life of frozen fish, 133–40 shellfish, 104, 126, 129, 132, 140, 154 site security, 283–4 skinning, 124 smoking, 124–7, 290 SQF, 92, 95–7 steam supply, 187, 204–5, 297 sterilisation CUT (come-up time), 181 end over end rotation, 185, 193 F0 values, 181–2, 193, 197, 209, 232–4, 255 headspace in cans, 186 heat penetration tests, 181, 209 holding time, 183, 188, 191 lethal rates, 182 overpressure, 183, 186, 188, 191, 194

304

Index

sterilisation (cont.) pilot retorts, 193–4 pre-process spoilage, 197 rotary sterilisation, 184–7 sterilisation cycle, 180–81 temperature distribution, 183, 184, 192, 208, 228–9 under-sterilisation, 192, 211, 216, 220, 222 venting, 183, 188 storage temperatures of frozen fish, 137–8 thawing of frozen fish, 145–9 thermal process management, 210–17 better process schools, 210 calibration of retort instrumentation, 213–14 heat penetration testing, 211, 213, 231 mathematical modelling, 216 NFPA Bulletin 26L, 211 process deviation management, 215–17 reconciliation/confirmation of sterilisation, 215 retort surveys, 212 review of production records, 215 temperature distribution testing, 211–2 TPA (thermal process authority), 210, 225 TPM (thermal process manager), 210 training of key retort personnel, 214 thermal process requirements for Canada, 42 thermal process requirements for the United States, 48 thermal process validation, 225–37 Clostridium botulinum, 231 cold point determination, 231, 234 commercial sterility, 231–3 data analysis, 230–31 data loggers, 226 deflection transducers, 228, 236 Department of Health Guidelines, 226, 229–31 D-value, 231 F0 value, 232–4 flexible packaging, 235–6 general method of calculation F0 values, 233–4 heat penetration measurement, 234 lethality calculation, 228, 231–4 probe positions, 230 process delays, 235 retort factors in process validation, 229 scramble packing of retort baskets, 235 temperature distribution, 228, 234

temperature measurement systems, 226–8 temperature sensors, 226 water flow, 230 wireless data logging system, 227 z-value, 231–4 thermometers MIG (mercury in glass) thermometer, 183, 199 MTI (master temperature indicator), 214, 230, 234 PRT (platinum resistance) thermometer, 199, 226 temperature recorder chart, 199 thermistors, 226 thermocouples, 226, 230 third countries, 8–9 three-piece cans, 159–62 tiles floor, 288 grouting EN 12004:2001, 287 tinplate, 158 tin free steel, 158 TMA (trimethylamine), 134, 218 toilets HSE INDG293, 290 traceability, 3, 111, 242–3, 246, 292, 294 training, 214, 247, 281 tuna, 105, 111, 127, 132, 153–6, 218, 221 tuna and bonito definitions, 5–6 TVBN, 130 two-piece cans, 162–4 under-processing, 192, 211, 216 UV water treatment, 297 vacuum in canned fish for Canada, 41 vacuum packing of frozen fish, 136 validation and verification of HACCP, 70–72 waste removal effluent treatment, 295 waste accumulation, 295 waste disposal, 295 waste microbiological, 294 water can cooling water, 184, 192, 203, 205–7, 211, 212, 219, 222, 256, 296–7 EU Drinking Water Directive EU 98/83/EC, 296 potable water, 8, 191, 203, 256 water supply, 296 weights and measures, 28–9 withdrawal and recall, 3–4