Chemistry and Technology of Soft Drinks and Fruit Juices Chemistry and Technology of Soft Drinks and Fruit Juices Edited by Philip R. Ashurst T h i rd E ditio n This edition first published 2016 © 2016 by John Wiley & Sons, Ltd. Registered Office John Wiley & Sons, Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial Offices 9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK 111 River Street, Hoboken, NJ 07030‐5774, 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.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.
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Cover image: © azureforest/DigitalVision Vectors Set in 9.5/13pt Meridien by SPi Global, Pondicherry, India 1 2016 Contents Contributors, xv Preface, xvi 1 Introduction, 1 P.1 Ready‐to‐drink products, 2 1.2 Concentrated soft drinks, 2 1.7 New product trends, 8 1.5 Summary, 14 References and further reading, 14 2 Trends in beverage markets, 15 E.3 Beverage consumption trends, 16 2.2 Carbonated soft drinks, 17 2.3 100% juices, nectars and fruit drinks, 19 2.5 Ready‐to‐drink (RTD) tea and ready‐to‐drink coffee, 20 2.10 Milk and flavoured milks, 22 v vi Contents 2.5 Regions and markets, 25 2.6 Market share charts, 26 2.7 Main drivers in consumption, 28 2.1 The search for ‘natural’, 28 2.2 Adult soft drinks, 29 2.8 Conclusion, 29 3 Fruit and juice processing, 31 B.1 Botanical aspects and classification of fruit types, 32 3.2 Harvesting considerations for berry, citrus, pome, stone and exotic fruits, 35 3.3 Fruit types for processing, 36 3.4 General comments on fruit juice processing, 39 3.1 Processing of ‘fleshy’ fruits, 40 3.2 The use of enzymes in fruit juice processing, 43 3.3 Extraction of citrus juices, 46 3.5 Juice processing following extraction, ‘cleaning’ and clarification, 48 3.1 Juice concentration by evaporation, 49 3.3 Hyper‐ and ultrafiltration, 50 3.1 Spinning cone column, 52 3.2 Composition of fruit juice volatiles, 53 3.1 European fruit juice and nectars directive and associated regulations, 54 3.3 Labelling regulations and authenticity, 57 3.4 Juice in the diet – ‘five‐a‐day’, 58 3.9 In conclusion, 62 References and further reading, 64 4 Water and the soft drinks industry, 65 T.1 Usage of water in the industry, 65 4.2 Sources of water, 66 Contents vii 4.3 Quality standards relating to water, 68 4.1 UK legislative standards, 68 4.2 Internal and customer standards, 68 4.5 Analytical and microbiological testing of water, 83 4.1 Potential contaminants of water waste, 84 4.2 Use of ‘grey’ water, 85 4.3 Clean‐up and reuse of effluents, 85 Further reading, 87 References, 87 5 Other beverage ingredients, 88 B.2 Factors influencing development of the industry, 88 5.3 The move towards standardisation, 91 5.4 The constituents of a soft drink, 94 5.2 Quality of fresh water, 96 5.5 Water impurities and their effect, 97 5.1 Flavourings and legislation, 104 5.2 Flavourings in beverage application, 106 viii Contents 5.3 Water‐miscible flavourings, 106 5.4 Water‐dispersible flavourings, 107 5.1 Microorganisms and beverages, 116 5.3 Benzoic acid and benzoates, 119 5.4 Sorbic acid and sorbates, 119 5.10 Other functional ingredients, 120 5.4 Calcium disodium EDTA, 121 5.12 Future trends, 123 Further reading and references, 125 6 Non‐carbonated beverages, 126 P.5 Filling and packaging, 139 6.3 Ready‐to‐drink non‐carbonated products, 140 6.4 Manufacturing and packing, 141 6.4 Fruit juices and nectars, 142 6.2 Packaging, 144 Further reading, 145 7 Carbonated beverages, 146 D.3 Carbon dioxide production, 148 7.2 Direct combustion, 148 Contents ix 7.4 Delivery to the customer, 149 7.2 Counter‐pressure filler, 163 7.3 Other filler types, 167 7.4 Clean‐in‐place systems, 169 7.10 Future trends, 172 Further reading, 173 8 Processing and packaging, 174 R.2 Flip‐flop blending, 176 8.3 In‐pack pasteurisation, 179 8.5 Control of process plant, 181 8.6 Factory layout and operation, 182 8.7 Hazard Analysis Critical Control Points, 186 8.8 Good manufacturing practice, 186 8.9 Cleaning in place, 187 8.11 Conclusion, 191 9 Packaging materials, 192 D.2 Commercial and technical considerations, 193 x Contents 9.2 In‐pack pasteurising, 197 9.4 Aseptic filling of bottles, 198 9.5 Liquid nitrogen injection, 202 9.3 High‐density polyethylene, 207 9.1 Metal roll‐on or roll‐on pilfer‐proof closures, 209 9.2 Vacuum seal closures, 210 9.13 Conclusions, 228 Acknowledgements, 230 10 Analysis of soft drinks and fruit juices, 231 D.1 Analysis of natural sweeteners, 240 10.2 Analysis of high‐intensity sweeteners, 245 10.1 Benzoic and sorbic acids, 249 10.3 Dimethyldicarbonate, 252 Contents xi 10.10 Analysis of colours used in soft drinks, 261 10.1 Assessment of colour, 263 10.11 Vitamin analysis in soft drinks systems, 272 10.1 Fat‐soluble vitamins, 274 10.4 Vitamin analysis using immunological procedures, 275 10.12 Methods used to detect juice adulteration, 276 10.13 Methods used to assess the juice or fruit content of soft drinks, 280 10.14 Conclusions, 282 References, 283 11 Microbiology of soft drinks and fruit juices, 290 P.2 Composition of soft drinks and fruit juices in relation to spoilage, 291 11.3 Background microbiology – spoilage, 293 11.4 Microbiological safety problems, 299 11.5 Preservation and control measures, 299 11.6 Sampling for microbial problems, 301 11.7 Identification schemes and interpretation, 301 11.2 Non‐molecular methods, 302 11.8 Brief spoilage case studies, 303 xii Contents 11.9 Conclusions, 304 References, 306 Further reading, 309 12 Functional drinks containing herbal extracts, 310 E.2 The extraction process, 313 12.3 An extraction operation, 320 12.4 Extract characteristics and their problems, 331 12.5 Incorporation of extracts in beverages, 333 12.1 Fruit juice‐based and fruit‐flavoured drinks, 333 12.2 Mineral‐water based and flavoured water drinks, 334 12.3 Carbonated and dilutable drinks, 334 12.4 Energy and sports drinks, 334 12.6 Some commonly used herbs, 337 References, 354 13 Miscellaneous topics, 356 P.2 Calculation and declaration of nutrition information, 360 13.1 Definition and purpose, 363 13.3 The absorption of drinks, 365 13.1 Alcoholic‐type drinks, 369 13.3 Functional drinks or nutraceuticals, 371 13.4 Powder drinks, 372 Contents xiii 13.5 Dispensed soft drinks and juices, 372 13.2 Pre‐mix and post‐mix compared, 373 13.6 Post‐mix syrup formulation, 376 13.7 Post‐mix syrup packaging, 377 13.1 Why have specifications?, 378 13.2 What a specification should include, 378 13.3 Preparation of a specification, 378 13.7 Complaints and enquiries, 380 13.1 Soft drinks and dental damage, 383 13.2 Effect of colourings and preservatives, 386 13.9 Alternative processing methods, 388 13.1 Microwave pasteurisation technology, 388 13.2 High‐pressure processing, 393 13.3 Irradiation, 395 References, 396 Index, 398 contributors Philip R.
P R Ashurst and Associates, Ludlow, UK. Stuart Charters Bwlch Garneddog, Gwynedd, UK. Tony Griffiths Quality Systems Consultant, Chelmsford, UK. Hammond Fruit Juice and Authenticity Expert, Wolverhampton, UK.
Lea GlaxoSmithKline, Weybridge, UK. Quentin Palmer Schweppes Europe, Watford, UK. Renfrew Market Intelligence Director, Zenith International Ltd, Bath, UK. David Rose A Pkg Prf.
Packaging Development Manager, Britvic Soft Drinks, Hemel Hempstead, UK. Shaw Flavex International Limited, Kingstone, UK. David Steen Casa Davann, Murcia, Spain. Barry Taylor Firmenich (UK) Ltd.
Peter Wareing Principal Food Safety Advisor, Leatherhead Food Research, Leatherhead, UK. xv Preface The first edition of this book was published in 1998, and the second in 2005. Now, some ten year later, this third edition is published. Its aim remains that of providing an overview of the science and technology of soft drinks and fruit juice products, and of the industries that manufacture and support them.
The book is written for students and graduates in food science, chemistry and micro biology, those who are working in the beverage industry or its supply chain, or simply for any reader who wishes to know more about the subject. There can be few, if any countries, in the world that do not have a plant manufacturing these products, as they have a universal appeal to most con sumers of all ages. Soft drinks are available in virtually every city, town and village on the planet, as well as in aircraft and ships. The range of flavours and packaging formats is remarkable, as producers are always attempting to s timulate new interest.
There is no single definition for soft drinks but, in general terms, they are essentially non‐alcoholic beverages, excluding dairy products, tea and coffee. Fruit juices are, by definition, self‐explanatory, although the term is often misused to cover products that contain a proportion of juice. Soft drinks and fruit juices have, from time to time, been the subject of criti cism by various sections of the health community. In the past, this has been mainly because of the risk of tooth erosion.
There is now an issue of obesity in almost all developed countries, as well as associated diseases, such as type 2 diabetes. Sugar consumption is cited as a significant contributory factor. At the time of writing, there is considerable pressure on beverage manufac turers to reduce, or even remove, the sugar content of products. The issue is complicated by the wrong assumption that is often made, that the sugars occur ring naturally in fruit juices are added to the products.
Further confusion also arises because, in the United Kingdom and some other countries, public health bodies promote fruit juices as part of a healthy diet. Beverages, however, are far from the only source of sugar/carbohydrate intake, and it is important to recognise that they continue to play an important part in hydration and enjoy ment and, particularly for fruit juices, are part of a balanced and healthy intake of nutrients. The fundamental composition of soft drinks changes little, although manufac turers continually strive for new flavours and ingredients. The main changes that occur relate mostly to processing and packaging innovations and, in consequence, this book has a similar format to earlier editions.
The opening introductory xvi Preface xvii chapter sets the scene and is followed by a review of beverage markets. This second chapter includes references to beverage markets other than soft drinks and fruit juices, which helps put the various product categories into perspective. Chapter 3 is an updated review of fruit processing and fruit juices, while chapter 4 is a new inclusion, dealing with the most important, but most easily overlooked, common ingredient – water. The following two chapters are updates from the second edition and deal, respectively, with a comprehensive review of ingredients and non‐carbonated soft drinks.
Chapters 7 and 8 are inclusions from the second edition and deal, respec tively, with the particular issues of carbonated drinks and typical processing and packaging operations. Although the second edition included a chapter on pack aging materials, the corresponding contribution in this edition is a completely new inclusion.
