Chemistry of Food Additives and Preservatives

Dr Titus A. M. Msagati is a Senior Lecturer in the Department of Applied Chemistry at the University of Johannesburg, South Africa.

Preface ix Introduction x List of Abbreviations xiii 1 Antioxidants and Radical Scavengers 1 1.1 Chemistry of free radicals and antioxidants 1 1.2 Types of antioxidants 4 1.3 Efficacy of different antioxidants 7 1.4 Action mechanisms of antioxidants 9 1.5 Structure activity relationship of antioxidants 11 1.6 Factors affecting antioxidant activity 14 1.7 Quality assessment of dietary antioxidants 15 1.8 How safe are food antioxidants? 23 1.9 Summary 25 References 25 Further reading 31 2 Emulsifiers 33 2.1 Mechanisms of food emulsifiers 33 2.2 The role of emulsifiers in foods 35 2.3 Classification of emulsifiers 37 2.4 Types of food emulsifiers 38 2.5 Quality and analysis of food emulsifiers 58 2.6 Foods containing emulsifiers 60 References 62 Further reading 64 3 Stabilisers, Gums, Thickeners and Gelling Agents as Food Additives 67 3.1 Introduction to stabilisers, thickeners and gelling agents 67 3.2 Polysaccharides 68 3.3 Protein-based food stabilisers 77 3.4 Quality control of food stabilisers and thickeners 78 3.5 Analytical methods 78 References 80 Further reading 82 4 Sweeteners 83 4.1 Introduction to sweeteners 83 4.2 Properties of sweeteners 84 4.3 Intense sweeteners in foods 86 4.4 Bulk food sweeteners 92 4.5 Quality assurance and quality control 95 4.6 Analytical methods 98 References 98 Further reading 100 5 Fragrances, Flavouring Agents and Enhancers 102 5.1 Introduction to flavours and flavouring agents 102 5.2 Classification of food flavourings 103 5.3 Chemistry of food flavourings 105 5.4 Quality control of flavour compounds 119 5.5 Analytical methods for the analysis of food flavourings 120 References 121 Further reading 124 6 Food Acids and Acidity Regulators 125 6.1 What are food acids and acid regulators? 125 6.2 Types of food acids 126 6.3 Uses of food acids 128 References 129 Further reading 130 7 Food Colour and Colour Retention Agents 131 7.1 Why add colourants to foods? 131 7.2 Classification of food colourants 131 7.3 Overview of colourants 133 7.4 Chemistry of food colourants 143 7.5 Extraction from natural sources 143 7.6 Quality assurance of food colourants 144 7.7 Analytical methods 145 References 145 8 Flour Treatment/Improving Agents 148 8.1 What are flour treatment/improving agents? 148 8.2 Flour maturing agents 148 8.3 Flour bleaching agents 151 8.4 Flour processing agents 154 References 154 9 Anticaking Agents 155 9.1 The caking phenomena 155 9.2 Mechanisms of caking 156 9.3 Classification of anticaking agents 159 9.4 Anticaking agents in use 159 References 160 Further reading 161 10 Humectants 162 10.1 Humectants and moisture control 162 10.2 Classification of humectants 162 References 166 11 Antifoaming Agents 167 11.1 Sources of foam in food processing 167 11.2 Properties of antifoaming agents 168 11.3 Mechanisms of antifoaming and foam destabilisation 168 11.4 Synthetic defoamers 168 11.5 Natural defoamers 170 References 171 12 Minerals and Mineral Salts 172 12.1 The importance of minerals and mineral salts 172 12.2 Inorganic mineral salts 173 12.3 Organic mineral salts 175 References 176 13 Dietary Supplements 177 13.1 Introduction to dietary supplements 177 13.2 Classification of vitamins 178 13.3 Vitamin A (retinols) 179 13.4 Vitamin D (calciferol) 189 13.5 Vitamin E 194 13.6 Vitamin K 196 13.7 Vitamin B 199 13.8 Vitamin C (L-ascorbic acid) 210 13.9 Conclusions 212 References 213 14 Glazing Agents 218 14.1 Introduction to glazing agents 218 14.2 Mineral hydrocarbon glazes 218 14.3 Chemistry of MHCs 220 14.4 Conclusion 222 References 223 15 Preservatives 224 15.1 Preservatives: Past, present and future 224 15.2 Natural food preservatives 226 15.3 Traditional food preservation methods 231 15.4 Artificial preservative agents 232 15.5 Modern food preservation techniques 235 15.6 Safety concerns of food preservatives 237 15.7 Analytical methods for the determination of preservative residues 238 15.8 Conclusions 238 References 238 Further reading 243 16 Nutraceuticals and Functional Foods 244 16.1 What are nutraceuticals? 244 16.2 Classification of nutraceuticals 245 16.3 Mechanisms of action 246 16.4 Conclusion 253 References 254 Further reading 257 17 Nutritional Genomics: Nutrigenetics and Nutrigenomics 258 17.1 Nutrition and gene expression 258 17.2 Nutrigenetic areas of application 260 17.3 Analytical methods for nutrigenetical food functions 268 17.4 Conclusion 270 References 270 18 Probiotic Foods and Dietary Supplements 274 18.1 Microbial gut flora activity 274 18.2 Probiotics and nutrition 275 18.3 Probiotics and health 275 18.4 Safety and stability of probiotics 277 18.5 Suitable dietary carriers for probiotics 278 18.6 Assessment of probiotics in foodstuffs and supplements 279 18.7 Conclusions 280 References 281 19 Prebiotics 285 19.1 Prebiotics and health 285 19.2 Factors that influence the activity and effectiveness of prebiotics 286 19.3 Types of oligosaccharides 286 19.4 Quality assessment of prebiotics 289 19.5 Conclusions 290 References 290 20 Synbiotics 291 20.1 Synbiotic foods and health 291 20.2 Health benefits of synbiotics 292 20.3 Mechanism of action of synbiotics 293 20.4 The future of synbotic foods 294 References 294 21 Microencapsulation and Bioencapsulation 295 21.1 Introduction to microencapsulation and bioencapsulation 295 21.2 Commonly used food-grade microcapsules 297 21.3 Methods of food microencapsulation 303 21.4 Microencapsulation for food colourants 307 21.5 Bioencapsulation for probiotics 309 21.6 Conclusions 310 References 310 General Conclusions 314 Index 315