Food Packaging Technology Packaging Technology Series Series Editor: Geoff A. Giles, Global Pack Management, GlaxoSmithKline, London. A series which presents the current state of the art in chosen sectors of the packaging industry. Written at professional and reference level, it is directed at packaging technologists, those involved in the design and development of packaging, users of packaging and those who purchase packaging. The series will also be of interest to manufacturers of packaging machinery. Titles in the series: Design and Technology of Packaging Decoration for the Consumer Market Edited by G.A. Giles Materials and Development of Plastics Packaging for the Consumer Market Edited by G.A. Giles and D.R. Bain Technology of Plastics Packaging for the Consumer Market Edited by G.A. Giles and D.R. Bain Canmaking for Can Fillers Edited by T.A. Turner PET Packaging Technology Edited by D.W. Brooks and G.A. Giles Food Packaging Technology Edited by R. Coles, D. McDowell and M.J. Kirwan Packaging Closures and Sealing Systems Edited by N. Theobald FOOD PACKAGING TECHNOLOGY Edited by RICHARD COLES Consultant in Food Packaging, London DEREK MCDOWELL Head of Supply and Packaging Division Loughry College, Northern Ireland and MARK J. KIRWAN Consultant in Packaging Technology London Blackwell Publishing © 2003 by Blackwell Publishing Ltd Trademark Notice: Product or corporate names may be trademarks or registered Editorial Offices: trademarks, and are used only for identification 9600 Garsington Road, Oxford OX4 2DQ and explanation, without intent to infringe. Tel: +44 (0) 1865 776868 108 Cowley Road, Oxford OX4 1JF, UK First published 2003 Tel: +44 (0) 1865 791100 Blackwell Munksgaard, 1 Rosenørns Allè, Library of Congress Cataloging in P.O. Box 227, DK-1502 Copenhagen V, Publication Data Denmark A catalog record for this title is available Tel: +45 77 33 33 33 from the Library of Congress Blackwell Publishing Asia Pty Ltd, 550 Swanston Street, Carlton South, British Library Cataloguing in Victoria 3053, Australia Publication Data Tel: +61 (0)3 9347 0300 A catalogue record for this title is available Blackwell Publishing, 10 rue Casimir from the British Library Delavigne, 75006 Paris, France ISBN 1–84127–221–3 Tel: +33 1 53 10 33 10 Originated as Sheffield Academic Press Published in the USA and Canada (only) by Set in 10.5/12pt Times CRC Press LLC by Integra Software Services Pvt Ltd, 2000 Corporate Blvd., N.W. Pondicherry, India Boca Raton, FL 33431, USA Printed and bound in Great Britain, Orders from the USA and Canada (only) to using acid-free paper by CRC Press LLC MPG Books Ltd, Bodmin, Cornwall USA and Canada only: For further information on ISBN 0–8493–9788–X Blackwell Publishing, visit our website: The right of the Author to be identified as the www.blackwellpublishing.com Author of this Work has been asserted in accordance with the 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. This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. Contents Contributors xv Preface xvii 1 Introduction 1 RICHARD COLES 1.1 Introduction 1 1.2 Packaging developments – an historical perspective 2 1.3 Food supply and the protective role of packaging 4 1.4 The value of packaging to society 7 1.5 Definitions and basic functions of packaging 8 1.6 Packaging strategy 9 1.7 Packaging design and development 9 1.7.1 The packaging design and development framework 12 1.7.1.1 Product needs 13 1.7.1.2 Distribution needs and wants of packaging 13 1.7.1.3 Packaging materials, machinery and production processes 16 1.7.1.4 Consumer needs and wants of packaging 18 1.7.1.5 Multiple food retail market needs and wants 22 1.7.1.6 Environmental performance of packaging 26 1.7.2 Packaging specifications and standards 28 1.8 Conclusion 29 Literature reviewed and sources of information 29 2 Food biodeterioration and methods of preservation 32 GARY S. TUCKER 2.1 Introduction 32 2.2 Agents of food biodeterioration 33 2.2.1 Enzymes 33 2.2.2 Microorganisms 34 2.2.2.1 Bacteria 35 2.2.2.2 Fungi 38 2.2.3 Non-enzymic biodeterioration 40 2.3 Food preservation methods 41 2.3.1 High temperature 41 2.3.1.1 Blanching 42 2.3.1.2 Thermal processing 42 2.3.1.3 Continuous thermal processing (aseptic) 47 2.3.1.4 Pasteurisation 51 2.3.2 Low temperature 52 2.3.2.1 Freezing 52 2.3.2.2 Chilling and cooling 53 vi CONTENTS 2.3.3 Drying and water activity control 54 2.3.4 Chemical preservation 56 2.3.4.1 Curing 57 2.3.4.2 Pickling 58 2.3.4.3 Smoking 58 2.3.5 Fermentation 59 2.3.6 Modifying the atmosphere 60 2.3.7 Other techniques and developments 61 2.3.7.1 High pressure processing 61 2.3.7.2 Ohmic heating 62 2.3.7.3 Irradiation 62 2.3.7.4 Membrane processing 62 2.3.7.5 Microwave processing 63 References 63 3 Packaged product quality and shelf life 65 HELEN BROWN and JAMES WILLIAMS 3.1 Introduction 65 3.2 Factors affecting product quality and shelf life 68 3.3 Chemical/biochemical processes 69 3.3.1 Oxidation 70 3.3.2 Enzyme activity 73 3.4 Microbiological processes 74 3.4.1 Examples where packaging is key to maintaining microbiological shelf life 75 3.5 Physical and physico-chemical processes 77 3.5.1 Physical damage 77 3.5.2 Insect damage 78 3.5.3 Moisture changes 78 3.5.4 Barrier to odour pick-up 81 3.5.5 Flavour scalping 81 3.6 Migration from packaging to foods 81 3.6.1 Migration from plastic packaging 83 3.6.2 Migration from other packaging materials 86 3.6.3 Factors affecting migration from food contact materials 88 3.6.4 Packaging selection to avoid migration and packaging taints 89 3.6.5 Methods for monitoring migration 89 3.7 Conclusion 91 References 91 4 Logistical packaging for food marketing systems 95 DIANA TWEDE and BRUCE HARTE 4.1 Introduction 95 4.2 Functions of logistical packaging 96 4.2.1 Protection 97 4.2.2 Utility/productivity 98 4.2.3 Communication 99 CONTENTS vii 4.3 Logistics activity-specific and integration issues 100 4.3.1 Packaging issues in food processing and retailing 100 4.3.2 Transport issues 101 4.3.3 Warehousing issues 104 4.3.4 Retail customer service issues 106 4.3.5 Waste issues 107 4.3.6 Supply chain integration issues 108 4.4 Distribution performance testing 109 4.4.1 Shock and vibration testing 110 4.4.2 Compression testing 111 4.5 Packaging materials and systems 112 4.5.1 Corrugated fiberboard boxes 112 4.5.2 Shrink bundles 115 4.5.3 Reusable totes 115 4.5.4 Unitization 116 4.6 Conclusion 119 References 119 5 Metal cans 120 BEV PAGE, MIKE EDWARDS and NICK MAY 5.1 Overview of market for metal cans 120 5.2 Container performance requirements 120 5.3 Container designs 121 5.4 Raw materials for can-making 123 5.4.1 Steel 123 5.4.2 Aluminium 124 5.4.3 Recycling of packaging metal 124 5.5 Can-making processes 124 5.5.1 Three-piece welded cans 125 5.5.2 Two-piece single drawn and multiple drawn (DRD) cans 126 5.5.3 Two-piece drawn and wall ironed (DWI) cans 127 5.6 End-making processes 129 5.6.1 Plain food can ends and shells for food/drink easy-open ends 130 5.6.2 Conversion of end shells into easy-open ends 130 5.7 Coatings, film laminates and inks 131 5.8 Processing of food and drinks in metal packages 132 5.8.1 Can reception at the packer 132 5.8.2 Filling and exhausting 133 5.8.3 Seaming 135 5.8.4 Heat processing 137 5.8.5 Post-process can cooling, drying and labelling 138 5.8.6 Container handling 139 5.8.7 Storage and distribution 140 5.9 Shelf life of canned foods 141 5.9.1 Interactions between the can and its contents 142 5.9.2 The role of tin 142 5.9.3 The dissolution of tin from the can surface 144 5.9.4 Tin toxicity 145 viii CONTENTS 5.9.5 Iron 146 5.9.6 Lead 147 5.9.7 Aluminium 147 5.9.8 Lacquers 147 5.10 Internal corrosion 148 5.11 Stress corrosion cracking 148 5.12 Environmental stress cracking corrosion of aluminium alloy beverage can ends 149 5.13 Sulphur staining 149 5.14 External corrosion 149 5.15 Conclusion 150 References and further reading 151 6 Packaging of food in glass containers 152 P.J. GIRLING 6.1 Introduction 152 6.1.1 Definition of glass 152 6.1.2 Brief history 152 6.1.3 Glass packaging 152 6.1.4 Glass containers market sectors for foods and drinks 153 6.1.5 Glass composition 153 6.1.5.1 White flint (clear glass) 153 6.1.5.2 Pale green (half white) 154 6.1.5.3 Dark green 154 6.1.5.4 Amber (brown in various colour densities) 154 6.1.5.5 Blue 154 6.2 Attributes of food packaged in glass containers 154 6.2.1 Glass pack integrity and product compatibility 156 6.2.1.1 Safety 156 6.2.1.2 Product compatibility 156 6.2.2 Consumer acceptability 156 6.3 Glass and glass container manufacture 156 6.3.1 Melting 156 6.3.2 Container forming 157 6.3.3 Design parameters 158 6.3.4 Surface treatments 158 6.3.4.1 Hot end treatment 158 6.3.4.2 Cold end treatment 159 6.3.4.3 Low-cost production tooling 160 6.3.4.4 Container inspection and quality 161 6.4 Closure selection 163 6.4.1 Normal seals 164 6.4.2 Vacuum seals 164 6.4.3 Pressure seals 164 6.5 Thermal processing of glass packaged foods 165 6.6 Plastic sleeving and decorating possibilities 165 6.7 Strength in theory and practice 166 6.8 Glass pack design and specification 167 6.8.1 Concept and bottle design 167 6.9 Packing – due diligence in the use of glass containers 169 CONTENTS ix 6.10 Environmental profile 171 6.10.1 Reuse 171 6.10.2 Recycling 171 6.10.3 Reduction – lightweighting 172 6.11 Glass as a marketing tool 172 References 172 Further reading 173 7 Plastics in food packaging 174 MARK J.