Chemistry and Technology of Soft Drinks and Fruit Juices

Soft drinks and fruit juices are produced in almost every country in the world and their availability is remarkable. From the largest cities to some of the remotest villages, soft drinks are available in a variety of flavours and packaging. Over the last decade, soft drinks and fruit juices have been the subject of criticism by the health community and there is considerable pressure on beverage manufacturers to reduce, or even remove, the sugar content of these products. Chemistry and Technology of Soft Drinks and Fruit Juices, Third Edition provides an overview of the chemistry and technology of soft drinks and fruit juices, covering ingredients, processing, microbiology, traceability and packaging as well as global market trends. This fully revised edition now includes chapters on topics that have become prominent in the industry since publication of the previous edition namely: water use and treatment, and microbiology technologies. The book is directed at graduates in food science, chemistry or microbiology entering production, quality control, new product development or marketing in the beverage industry or in companies supplying ingredients or packaging materials to the beverage industry.

Table of Contents:
Contributors xv Preface xvi 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 3 1.2.4 Product types 4 1.2.5 Development trends 6 1.2.6 Nutrition 7 1.2.7 New product trends 8 1.3 Fruit juices 8 1.3.1 Processing technology 9 1.3.2 Adulteration 10 1.3.3 Other processes 12 1.3.4 Nutrition 12 1.4 Packaging 13 1.5 Summary 14 References and further reading 14 2 Trends in beverage markets 15 E.C. Renfrew 2.1 Introduction 15 2.2 Definitions 15 2.3 Beverage consumption trends 16 2.3.1 Bottled water 17 2.3.2 Carbonated soft drinks 17 2.3.3 100% juices nectars and fruit drinks 19 2.3.4 Energy drinks 19 2.3.5 Ready‐to‐drink (RTD) tea and ready‐to‐drink coffee 20 2.3.6 Coffee 20 2.3.7 Tea 21 2.3.8 Beer 21 2.3.9 Wine 22 2.3.10 Milk and flavoured milks 22 2.4 Consumption charts 23 2.5 Regions and markets 25 2.6 Market share charts 26 2.7 Main drivers in consumption 28 2.7.1 The search for ‘natural’ 28 2.7.2 Adult soft drinks 29 2.7.3 Protein drinks 29 2.8 Conclusion 29 3 Fruit and juice processing 31 B. Taylor 3.1 Introduction 31 3.2 Fruit types 32 3.2.1 Botanical aspects and classification of fruit types 32 3.2.2 Harvesting considerations for berry citrus pome stone and exotic fruits 35 3.3 Fruit types for processing 36 3.3.1 Pome fruits 36 3.3.2 Citrus fruits 38 3.4 General comments on fruit juice processing 39 3.4.1 Processing of ‘fleshy’ fruits 40 3.4.2 The use of enzymes in fruit juice processing 43 3.4.3 Extraction of citrus juices 46 3.5 Juice processing following extraction ‘cleaning’ and clarification 48 3.5.1 Juice concentration by evaporation 49 3.5.2 Freeze concentration 50 3.5.3 Hyper‐ and ultrafiltration 50 3.6 Volatile components 51 3.6.1 Spinning cone column 52 3.6.2 Composition of fruit juice volatiles 53 3.7 Legislative concerns 54 3.7.1 European fruit juice and nectars directive and associated regulations 54 3.7.2 AIJN Guidelines 56 3.7.3 Labelling regulations and authenticity 57 3.7.4 Juice in the diet – ‘five‐a‐day’ 58 3.8 Quality issues 58 3.8.1 Absolute requirements 58 3.9 In conclusion 62 References and further reading 64 4 Water and the soft drinks industry 65 T. Griffiths 4.1 Usage of water in the industry 65 4.2 Sources of water 66 4.2.1 Water cycle 66 4.2.2 Surface water 67 4.2.3 Ground water 67 4.3 Quality standards relating to water 68 4.3.1 UK legislative standards 68 4.3.2 Internal and customer standards 68 4.4 Processing water 69 4.4.1 Required quality 69 4.4.2 Starting quality 72 4.4.3 Processing options 75 4.5 Analytical and microbiological testing of water 83 4.5.1 Chemical tests 83 4.5.2 Microbiological tests 84 4.6 Effluents 84 4.6.1 Potential contaminants of water waste 84 4.6.2 Use of ‘grey’ water 85 4.6.3 Clean‐up and reuse of effluents 85 Further reading 87 References 87 5 Other beverage ingredients 88 B. Taylor 5.1 Introduction 88 5.2 Factors influencing development of the industry 88 5.3 The move towards standardisation 91 5.4 The constituents of a soft drink 94 5.5 Water 94 5.5.1 Requirements 94 5.5.2 Quality of fresh water 96 5.5.3 Water hardness 96 5.5.4 Water treatment 96 5.5.5 Water impurities and their effect 97 5.6 Acidulents 98 5.6.1 Citric acid 98 5.6.2 Tartaric acid 99 5.6.3 Phosphoric acid 100 5.6.4 Lactic acid 101 5.6.5 Acetic acid 101 5.6.6 Malic acid 101 5.6.7 Fumaric acid 101 5.6.8 Ascorbic acid 102 5.7 Flavourings 102 5.7.1 Flavourings and legislation 104 5.7.2 Flavourings in beverage application 106 5.7.3 Water‐miscible flavourings 106 5.7.4 Water‐dispersible flavourings 107 5.8 Colours 112 5.9 Preservatives 115 5.9.1 Microorganisms and beverages 116 5.9.2 Sulphur dioxide 117 5.9.3 Benzoic acid and benzoates 119 5.9.4 Sorbic acid and sorbates 119 5.10 Other functional ingredients 120 5.10.1 Stabilisers 120 5.10.2 Saponins 120 5.10.3 Antioxidants 121 5.10.4 Calcium disodium EDTA 121 5.11 Food safety 122 5.12 Future trends 123 Further reading and references 125 6 Non‐carbonated beverages 126 P.R. Ashurst 6.1 Introduction 126 6.2 Dilutable beverages 127 6.2.1 Overview 127 6.2.2 Nomenclature 127 6.2.3 Ingredients 128 6.2.4 Manufacturing operations 137 6.2.5 Filling and packaging 139 6.2.6 Product range 140 6.3 Ready‐to‐drink non‐carbonated products 140 6.3.1 Overview 140 6.3.2 Formulations 140 6.3.3 Special problems 140 6.3.4 Manufacturing and packing 141 6.3.5 Packaging types 142 6.4 Fruit juices and nectars 142 6.4.1 Processing 142 6.4.2 Packaging 144 Further reading 145 7 Carbonated beverages 146 D. Steen 7.1 Introduction 146 7.2 Carbon dioxide 147 7.3 Carbon dioxide production 148 7.3.1 Fermentation 148 7.3.2 Direct combustion 148 7.3.3 Quality standards 149 7.3.4 Delivery to the customer 149 7.3.5 Precautions 150 7.4 Carbonation 152 7.4.1 Basic considerations 152 7.4.2 Carbonation measurement 154 7.5 Syrup preparation 156 7.6 De‐aeration 157 7.7 Carbonators 158 7.8 Filling principles 160 7.8.1 Gravity filler 161 7.8.2 Counter‐pressure filler 163 7.8.3 Other filler types 167 7.8.4 Clean‐in‐place systems 169 7.9 Process control 171 7.10 Future trends 172 Further reading 173 8 Processing and packaging 174 R.A.W. Lea 8.1 Introduction 174 8.2 Juice extraction 174 8.3 Blending 175 8.3.1 Batch blending 176 8.3.2 Flip‐flop blending 176 8.3.3 Continuous blending 176 8.4 Processing 177 8.4.1 Flash pasteurisation 177 8.4.2 Hot filling 178 8.4.3 In‐pack pasteurisation 179 8.4.4 Aseptic filling 179 8.4.5 Chilled distribution 181 8.4.6 Summary 181 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 8.10 Packaging 188 8.11 Conclusion 191 9 Packaging materials 192 D. Rose 9.1 Introduction 192 9.2 Commercial and technical considerations 193 9.2.1 General considerations 193 9.2.2 Packaging materials 195 9.3 Processing 197 9.3.1 Cold‐filling 197 9.3.2 In‐pack pasteurising 197 9.3.3 Hot‐filling 198 9.3.4 Aseptic filling of bottles 198 9.3.5 Liquid nitrogen injection 202 9.4 Bottles 202 9.4.1 Glass 202 9.4.2 Polyethylene terephthalate 203 9.4.3 High‐density polyethylene 207 9.4.4 Polypropylene 207 9.4.5 Polyvinyl chloride 207 9.4.6 Plastic properties 208 9.5 Closures 209 9.5.1 Metal roll‐on or roll‐on pilfer‐proof closures 209 9.5.2 Vacuum seal closures 210 9.5.3 Plastic closures 211 9.5.4 Crown corks 213 9.6 Cans 213 9.6.1 Metal bottles 218 9.6.2 Plastic cans 218 9.7 Cartons 218 9.8 Flexible pouches 221 9.9 Multipacks 222 9.10 Secondary packaging 223 9.11 Pack decoration 224 9.12 Environmental considerations 225 9.13 Conclusions 228 Acknowledgements 230 10 Analysis of soft drinks and fruit juices 231 D.A. Hammond 10.1 Introduction 231 10.2 Laboratory accreditation 234 10.3 Sensory evaluation 236 10.4 Water 237 10.5 Sweeteners 239 10.5.1 Analysis of natural sweeteners 240 10.5.2 Analysis of high‐intensity sweeteners 245 10.6 Preservatives 249 10.6.1 Benzoic and sorbic acids 249 10.6.2 Sulphur dioxide 251 10.6.3 Dimethyldicarbonate 252 10.7 Acidulants 252 10.8 Carbonation 256 10.9 Miscellaneous additives 257 10.9.1 Caffeine 257 10.9.2 Quinine 258 10.9.3 Other additives 258 10.9.4 Fibre analysis 259 10.9.5 Herbal drinks 260 10.9.6 Osmolality 261 10.10 Analysis of colours used in soft drinks 261 10.10.1 Assessment of colour 263 10.10.2 Synthetic colours 265 10.10.3 Natural pigments 267 10.11 Vitamin analysis in soft drinks systems 272 10.11.1 Fat‐soluble vitamins 274 10.11.2 Vitamin B class 274 10.11.3 Vitamin C 275 10.11.4 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. Wareing 11.1 Introduction 290 11.2 Composition of soft drinks and fruit juices in relation to spoilage 291 11.3 Background microbiology – spoilage 293 11.3.1 Sources 293 11.3.2 Yeasts 294 11.3.3 Bacteria 295 11.3.4 Moulds 297 11.4 Microbiological safety problems 299 11.4.1 Escherichia coli 299 11.4.2 Salmonella 299 11.5 Preservation and control measures 299 11.6 Sampling for microbial problems 301 11.7 Identification schemes and interpretation 301 11.7.1 Sample isolation 301 11.7.2 Non‐molecular methods 302 11.7.3 Molecular identification 302 11.8 Brief spoilage case studies 303 11.9 Conclusions 304 References 306 Further reading 309 12 Functional drinks containing herbal extracts 310 E.F. Shaw and S. Charters 12.1 History 310 12.2 The extraction process 313 12.2.1 Extraction heritage 314 12.3 An extraction operation 320 12.3.1 Raw materials 321 12.3.2 Extraction 323 12.3.3 Organic extracts 329 12.3.4 Extract costs 329 12.4 Extract characteristics and their problems 331 12.4.1 Specifications 331 12.4.2 Stability 331 12.4.3 Hazing 332 12.4.4 Availability 333 12.5 Incorporation of extracts in beverages 333 12.5.1 Fruit juice‐based and fruit‐flavoured drinks 333 12.5.2 Mineral‐water based and flavoured water drinks 334 12.5.3 Carbonated and dilutable drinks 334 12.5.4 Energy and sports drinks 334 12.5.5 Regulatory issues 335 12.6 Some commonly used herbs 337 References 354 13 Miscellaneous topics 356 P.R. Ashurst and Q. Palmer 13.1 Introduction 356 13.2 Nutrition 356 13.2.1 Nutritional components 357 13.2.2 Calculation and declaration of nutrition information 360 13.3 Sports drinks 363 13.3.1 Definition and purpose 363 13.3.2 Physiological needs 363 13.3.3 The absorption of drinks 365 13.3.4 Formulation 366 13.4 Niche drinks 369 13.4.1 Alcoholic‐type drinks 369 13.4.2 Energy drinks 370 13.4.3 Functional drinks or nutraceuticals 371 13.4.4 Powder drinks 372 13.5 Dispensed soft drinks and juices 372 13.5.1 Introduction 372 13.5.2 Pre‐mix and post‐mix compared 373 13.5.3 Equipment 373 13.5.4 Outlets 375 13.5.5 Hygiene 375 13.5.6 Post‐mix syrup formulation 376 13.5.7 Post‐mix syrup packaging 377 13.6 Ingredient specifications 378 13.6.1 Why have specifications? 378 13.6.2 What a specification should include 378 13.6.3 Preparation of a specification 378 13.6.4 Supplier performance 379 13.7 Complaints and enquiries 380 13.7.1 Complaints 380 13.7.2 Enquiries 382 13.8 Health issues 383 13.8.1 Soft drinks and dental damage 383 13.8.2 Effect of colourings and preservatives 386 13.8.3 Obesity 387 13.9 Alternative processing methods 388 13.9.1 Microwave pasteurisation technology 388 13.9.2 High‐pressure processing 393 13.9.3 Irradiation 395 References 396 Index 398

About the Author :
Dr Philip R. Ashurst, Ashurst and Associates, Consulting Chemists to the Food Industry, Ludlow, UK.