Chemistry and technology of soft drinks and fruit juices

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 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 vi CONTENTS 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 CONTENTS vii 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 viii CONTENTS 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 CONTENTS ix 8.3.2 Flip-flop blending 184 8.3.3 Continuous blending 184 8.4 Processing 184 8.4.1 Flash pasteurisation 185 8.4.2 Hot filling 186 8.4.3 In-pack pasteurisation 187 8.4.4 Aseptic filling 187 8.4.5 Chilled distribution 189 8.4.6 Summary 189 8.5 Control of process plant 189 8.6 Factory layout and operation 190 8.7 Hazard Analysis Critical Control Points 194 8.8 Good manufacturing practice 194 8.9 Cleaning in place 195 8.10 Packaging 196 8.11 Conclusion 198 9 Packaging materials 200 G.A. GILES 9.1 Introduction 200 9.2 Commercial and technical considerations 200 9.2.1 General considerations 200 9.2.2 Packaging materials 202 9.3 Processing 203 9.3.1 Cold-filling 204 9.3.2 In-pack pasteurising 204 9.3.3 Hot-filling 205 9.3.4 Aseptic filling 205 9.4 Bottles 208 9.4.1 Glass 208 9.4.2 Polyethylene terephthalate 210 9.4.3 Polyvinyl chloride 212 9.4.4 High-density polyethylene 212 9.4.5 Polypropylene 213 9.4.6 Plastics permeability data 213 9.5 Closures 213 9.5.1 Metal roll-on or roll-on pilfer-proof closures 213 9.5.2 Vacuum seal closures 215 9.5.3 Plastic closures 217 9.6 Cans 218 9.6.1 Liquid nitrogen injection 222 9.6.2 Plastic cans 222 9.7 Cartons 223 9.8 Flexible pouches 229 9.9 Secondary packaging 230 9.10 Pack decoration 231 9.11 Environmental considerations 232 9.12 Conclusions 234 Acknowledgements 235 Further reading 235 x CONTENTS 10 Analysis of soft drinks and fruit juices 236 D.A. HAMMOND 10.1 Introduction 236 10.2 Sensory evaluation 238 10.3 Water 238 10.4 Sweeteners 240 10.4.1 Analysis of natural sweeteners 240 10.4.2 Analysis of high-intensity sweeteners 244 10.5 Preservatives 247 10.5.1 Benzoic and sorbic acids and para-hydroxybenzoates 248 10.5.2 Sulphur dioxide 249 10.6 Acidulants 250 10.7 Carbonation 253 10.8 Miscellaneous additives 255 10.8.1 Caffeine 255 10.8.2 Quinine 256 10.8.3 Taurine 256 10.8.4 Fibre analysis 257 10.8.5 Herbal drinks 257 10.8.6 Osmolality 258 10.9 Analysis of colours used in soft drinks 258 10.9.1 Assessment of colour 259 10.9.2 Synthetic colours 261 10.9.3 Natural pigments 263 10.9.3.1 Anthocyanin pigments 263 10.9.3.2 Carotenoid-type materials 266 10.10 Vitamin analysis in soft drinks systems 267 10.10.1 Fat-soluble vitamins 268 10.10.2 Vitamin B class 269 10.10.3 Vitamin C 269 10.11 Methods used to detect juice adulteration 270 10.12 Methods used to assess the juice or fruit content of a soft drink 272 10.13 Conclusions 273 References 274 11 Microbiology of soft drinks and fruit juices 279 P. WAREING and R.R. DAVENPORT 11.1 Introduction 279 11.2 Composition of soft drinks and fruit juices in relation to spoilage 279 11.3 Background microbiology – spoilage 281 11.3.1 Sources 281 11.3.2 Yeasts 281 11.3.3 Bacteria 283 11.3.4 Moulds 284 11.3.4.1 Mycotoxins 285 11.4 Microbiological safety problems 286 11.4.1 Escherichia coli 286 11.4.2 Salmonella 286 CONTENTS xi xii CONTENTS 11.5 Control Measures 286 11.6 Forensic grouping and applications 287 11.6.1 Forensic grouping 287 11.6.2 Group formats 287 11.7 Suggested test programme 288 11.7.1 Packaged products 288 11.7.1.1 Spoilage symptoms: dominant feature fermentation 288 11.7.1.2 No obvious symptoms 289 11.7.2 Key raw materials 290 11.7.3 Environmental samples 291 11.8 Conclusions 292 Appendix 11.1 Conclusions from environmental audit inspections 293 Appendix 11.2 Examples of environmental microbial indicators 293 Appendix 11.3 Simple recognition and identification of Group 1–4 micro-organisms 294 Appendix 11.4 Media for cultivation of industrial micro-organisms 296 References 297 Further reading 299 12 Functional drinks containing herbal extracts 300 J. WHITEHEAD 12.1 Introduction 300 12.1.1 History 300 12.1.2 Market development over the past 15 years 301 12.1.3 The role of herbal extracts in beverages 302 12.2 Overview of the extraction process 302 12.2.1 Extraction heritage 303 12.2.1.1 Infusion 303 12.2.1.2 Decoction 303 12.2.1.3 Tincture 303 12.2.1.4 Liquid or fluid extract 304 12.2.1.5 Soft extract 304 12.2.1.6 Powdered extract 304 12.2.1.7 Percolation 304 12.2.1.8 Modern extracts 304 12.2.2 The extraction operation 305 12.2.2.1 Raw materials 305 12.2.3 Extraction 307 12.2.3.1 Particle size 308 12.2.3.2 Time 309 12.2.3.3 Temperature 310 12.2.3.4 Solvent 310 12.2.3.5pH 312 12.2.3.6 Summary 312 12.2.4 Organic extracts 312 12.2.5 Extract costs 313 12.3 Extract characteristics and their problems 313 12.3.1 Specifications 313 12.3.2 Stability 314 12.3.3 Hazing 314 12.3.4 Availability 315 12.4 Extracts and their applications 315 12.4.1 Infusions 315 12.4.2 Soft Extracts 316 12.4.3 Dry Extracts 316 12.4.4 Incorporation of extracts in beverages 316 12.4.4.1 Fruit-juice-based and fruit-flavoured drinks 316 12.4.4.2 Mineral-water-based drinks 317 12.4.4.3 Energy drinks 317 12.4.4.4 Regulatory issues 318 12.5 Some commonly used herbs 319 References and further reading 335 13 Special topics 336 Q. PALMER 13.1 Complaints and enquiries 336 13.1.1 Complaints 336 13.1.2 Enquiries 338 13.2 Nutrition 339 13.2.1 Nutritional components 340 13.2.1.1 Water 340 13.2.1.2 Carbohydrates 340 13.2.1.3 Protein 341 13.2.1.4 Fat 341 13.2.1.5 Fibre 342 13.2.1.6 Vitamins 342 13.2.1.7 Minerals 342 13.2.1.8 Energy 342 13.2.1.9 Low-calorie drinks 343 13.2.2 Calculation and declaration of nutrition information 343 13.3 Soft drinks and dental damage 346 13.3.1 Causes of dental damage 346 13.3.2 Can soft drinks cause dental damage? 347 13.3.3 Fluorides 348 13.3.4 Making soft drinks more tooth friendly 348 13.4 Ingredient specifications 350 13.4.1 Why have specifications? 350 13.4.2 What a specification should include 350 13.4.3 Preparation of a specification 351 13.4.4 Supplier performance 352 13.5 Sports drinks 352 13.5.1 Definition and purpose 352 13.5.2 Physiological needs 353 13.5.2.1 Energy 353 13.5.2.2 Water 353 13.5.2.3 Electrolytes 354 13.5.2.4 Vitamins 354 13.5.3 The absorption of drinks 354 CONTENTS xiii 13.5.3.1 Gastric emptying 355 13.5.3.2 Absorption from the intestine 355 13.5.3.3 Consumption pattern 355 13.5.4 Formulation 356 13.5.4.1 Preliminary stage 356 13.5.4.2 Palatability 357 13.5.4.3 Prototype development 358 13.5.4.4 Final formulation 358 13.5.4.5 Powdered sports drinks 358 13.6 Niche drinks 359 13.6.1 Alcoholic type drinks 359 13.6.2 Energy drinks 360 13.6.3 Functional drinks or nutraceuticals 360 13.6.4 Powder drinks 361 13.6.4.1 Manufacture 361 13.7 Dispensed soft drinks and juices 361 13.7.1 Introduction 361 13.7.2 Pre-mix and post-mix compared 362 13.7.3 Equipment 362 13.7.4 Outlets 364 13.7.5 Hygiene 365 13.7.6 Post-mix syrup formulation 365 13.7.7 Post-mix syrup packaging 366 13.7.7.1 Post-mix syrup production 366 13.7.7.2 Product quality at the outlet 367 13.7.7.3 Uncarbonated systems 367 References 367 Index 369