Chemistry and Technology of Soft Drinks and Fruit Juices Chemistry and Technology of Soft Drinks and Fruit Juices Second Edition Edited by Philip R. Ashurst Ashurst and Associates Consulting Chemists for the Food Industry Hereford,UK ©2005by Blackwell Publishing Ltd Editorial Offices: Blackwell Publishing Ltd,9600 Garsington Road,Oxford OX4 2DQ,UK Tel:(cid:2)44 (0)1865 776868 Blackwell Publishing Professional,2121 State Avenue,Ames,Iowa 50014-8300,USA Tel:(cid:2)1 515 292 0140 Blackwell Publishing Asia Pty Ltd,550 Swanston Street,Carlton,Victoria 3053,Australia Tel:(cid:2)61 (0)3 8359 1011 The right of the Author to be identified as the 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,photocopy- ing, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988,without the prior permission of the publisher. First edition published 1998 by Sheffield Academic Press Second edition published 2005 by Blackwell Publishing Ltd Library of Congress Cataloging-in-Publication Data The chemistry and technology of soft drinks and fruit juices / edited by Philip R. Ashurst. – 2nd ed. p. cm. Includes bibliographical references and index. ISBN 1–4051–2286–2 (hardback:alk. paper) 1. Soft drinks. 2. Fruit juices. I. Ashurst,Philip R. TP630.C5186 2004 663(cid:3). 62–dc22 2004010914 ISBN 1-4051-2286-2 A catalogue record for this title is available from the British Library Set in 10/12pt Times by Newgen Imaging Systems (P) Ltd,Chennai,India Printed and bound in Great Britain by MPG Books Ltd,Bodmin,Cornwall The publisher’s policy is to use permanent paper from mills that operate a sustainable forestry policy,and which has been manufactured from pulp processed using acid-free and elementary chlorine-free practices. Furthermore,the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards. For further information on Blackwell Publishing,visit our website: www.blackwellpublishing.com Contents List of Contributors xv Preface xvii 1 Introduction 1 P.R. ASHURST 1.1 Overview 1 1.2 Soft drinks 1 1.2.1 Ready-to-drink products 2 1.2.2 Concentrated soft drinks 2 1.2.3 Legislation 2 1.2.4 Product types 3 1.2.4.1 Ready-to-drink products 3 1.2.4.2 Dilutables 5 1.2.5 Development trends 5 1.2.6 Nutrition 6 1.2.7 New product trends 7 1.3 Fruit juices 8 1.3.1 Processing technology 8 1.3.2 Adulteration 10 1.3.3 Other processes 11 1.3.4 Nutrition 12 1.4 Packaging 13 1.5 Summary 13 References and further reading 13 2 Trends in beverage markets 15 G. ROETHENBAUGH 2.1 Introduction 15 2.2 Beverage consumption trends 16 2.3 Regions and markets 21 2.4 Soft drinks dynamics 25 2.5 Soft drinks industry issues 29 2.5.1 Obesity 29 2.5.2 Wellness and functionality 30 2.6 Beverage trends – outlook and conclusion 32 References and further reading 34 vi CONTENTS 3 Fruit and juice processing 35 BARRY TAYLOR 3.1 Introduction 35 3.2 Fruit types 36 3.2.1 Botanical aspects,classification of fruit types 36 3.2.1.1 The basics of plant reproduction and fruit formation 38 3.2.1.2 Respiration climacteric 39 3.2.2 Harvesting considerations for berry,citrus,pome, stone and exotic fruits 39 3.3 Fruit types for processing 41 3.3.1 Pome fruits 41 3.3.2 Citrus fruits 41 3.3.2.1 Orange 42 3.3.2.2 Lemon (C.limon) 42 3.3.2.3 Grapefruit (C.paradisi) 43 3.3.2.4 Lime (C.aurantifolia) 43 3.4 General comments on fruit juice processing 43 3.4.1 Processing of ‘fleshy’fruits 44 3.4.1.1 Pack press 44 3.4.1.2 The horizontal rotary press 44 3.4.1.3 The use of centrifuges in processing 45 3.4.2 The use of enzymes in fruit juice processing 47 3.4.3 Extraction of citrus juices 50 3.4.3.1 The Fruit Machinery Corporation extractor 50 3.5 Juice processing following extraction,‘cleaning’and clarification 51 3.5.1 Juice concentration,by evaporation 52 3.5.2 Freeze-concentration 54 3.5.3 Hyper- and ultrafiltration 54 3.6 Volatile components 55 3.6.1 Spinning cone column 56 3.6.2 Fruit juice volatiles composition 57 3.7 Legislative concerns 58 3.7.1 European fruit juice and nectars directive 58 3.7.2 AIJN guidelines 59 3.7.3 Labelling regulations and authenticity 59 3.8 Quality issues 60 3.8.1 Absolute requirements 61 3.8.1.1 Soluble solids 61 3.8.1.2 Titratable acidity 61 3.8.1.3 Other quality considerations 64 3.9 Conclusions 66 References and further reading 66 4 Carbohydrate and intense sweeteners 68 K. O’DONNELL 4.1 Overview 68 4.2 Carbohydrate sweeteners 68 CONTENTS vii 4.2.1 Sucrose 69 4.2.1.1 Manufacture 69 4.2.2 Glucose syrups/high-fructose glucose syrups 71 4.2.3 Fructose (levulose) 71 4.3 Overview – intense sweeteners 72 4.3.1 Sweetener approval 73 4.3.2 Labelling 74 4.3.3 Main intense sweeteners in use in soft drinks 75 4.3.3.1 Acesulfame K 75 4.3.3.2 Aspartame 76 4.3.3.3 Alitame 78 4.3.3.4 Cyclamate 79 4.3.3.5 Neohesperidin Dihydrochalcone 80 4.3.3.6 Sucralose 80 4.3.3.7 Neotame 81 4.3.3.8 Saccharin 82 4.3.3.9 Stevioside 82 4.4 New sweeteners/bulking agents used in soft drinks 84 4.4.1 Inulin 84 4.4.2 Fructo-oligosaccharides/oligofructose 85 4.4.3 Polydextrose 85 4.4.4 Trehalose 86 4.4.5 Tagatose 86 4.5 The future 87 References 87 5 Other beverage ingredients 90 BARRY TAYLOR 5.1 Introduction 90 5.2 Factors influencing the development of the industry 90 5.3 The move towards standardisation 93 5.4 The constituents of a soft drink 94 5.5 Water 95 5.5.1 Requirements 95 5.5.2 Quality of fresh water 97 5.5.3 Water hardness 97 5.5.4 Water treatment 97 5.5.5 Water impurities and their effect 98 5.5.5.1 Suspended particles 98 5.5.5.2 Organic matter 98 5.5.5.3 High alkalinity 99 5.5.5.4 Nitrates 99 5.6 Acidulants 99 5.6.1 Citric acid 99 5.6.2 Tartaric acid 100 5.6.3 Phosphoric acid 101 5.6.4 Lactic acid 102 5.6.5 Acetic acid 102 viii CONTENTS 5.6.6 Malic acid 102 5.6.7 Fumaric acid 103 5.6.8 Ascorbic acid 103 5.7 Flavourings 104 5.7.1 Flavourings and legislation 105 5.7.2 Flavourings in application 106 5.7.3 Water-miscible flavourings 107 5.7.3.1 Flavouring mixtures 107 5.7.3.2 Flavouring essence 108 5.7.4 Water-dispersible flavourings 108 5.7.4.1 Oil phase 110 5.7.4.2 Water phase 111 5.7.4.3 Brominated vegetable oil emulsions 112 5.8 Colours 113 5.9 Preservatives 116 5.9.1 Micro-organisms and beverages 117 5.9.2 Sulphur dioxide 118 5.9.3 Benzoic acid and benzoates 120 5.9.4 Sorbic acid and sorbates 120 5.10 Other functional ingredients 121 5.10.1 Stabilisers 121 5.10.2 Saponins 121 5.10.3 Antioxidants 122 5.10.4 Calcium disodium EDTA 123 5.11 Investigation of a finished soft drink 123 5.12 Food safety 126 5.13 Future trends 127 Further reading 128 6 Non-carbonated beverages 129 P.R. ASHURST 6.1 Introduction 129 6.2 Dilutable beverages 129 6.2.1 Overview 129 6.2.2 Nomenclature 130 6.2.3 Ingredients 131 6.2.3.1 Fruit components 131 6.2.3.2 Carbohydrates 134 6.2.3.3 Intense sweeteners 136 6.2.3.4 Other ingredients 138 6.2.4 Manufacturing operations 140 6.2.4.1 Ingredients 141 6.2.4.2 Mixing 141 6.2.4.3 Pasteurisation 142 6.2.4.4 Homogenisation 142 6.2.5 Filling and packaging 143 6.2.6 Product range 143 6.3 Ready-to-drink non-carbonated products 143 6.3.1 Overview 143 6.3.2 Formulations 143 CONTENTS ix 6.3.3 Special problems 144 6.3.4 Manufacturing and packing 144 6.3.5 Packaging types 144 6.4 Fruit juices and nectars 145 6.4.1 Processing 146 6.4.1.1 Flash pasteurisation 146 6.4.1.2 In-pack pasteurisation 146 6.4.1.3 Hot filling 147 6.4.1.4 High-pressure pasteurisation 147 6.4.2 Packaging 147 6.4.2.1 Boxes 147 6.4.2.2 Bottles 148 6.4.2.3 Cans 148 6.4.2.4 Bulk packs 148 Further reading 149 7 Carbonated beverages 150 D. STEEN 7.1 Introduction 150 7.2 Carbon dioxide 150 7.3 Carbon dioxide production 152 7.3.1 Fermentation 152 7.3.2 Direct combustion 152 7.3.3 Quality standards 153 7.3.4. Delivery to the customer 154 7.3.5. Precautions 155 7.4 Carbonation 155 7.4.1 Basic considerations 155 7.4.2 Carbonation measurement 159 7.5 Syrup preparation 161 7.6 De-aeration 163 7.7 Carbonators 164 7.8 Filling principles 165 7.8.1 Gravity filler 167 7.8.2 Counter-pressure filler 168 7.8.3 Other filler types 174 7.8.4 Clean-in-place systems 177 7.9 Process control 178 7.10 Future trends 180 Further reading 181 8 Processing and packaging 182 R.A.W. LEA 8.1 Introduction 182 8.2 Juice extraction 182 8.3 Blending 182 8.3.1 Batch blending 183