Fundamentals of food reaction technology

PREFACE 1. IMPORTANT PROBLEMS IN FOOD PROCESSING 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 Introduction Changes During Food Processing Food Products 1.3.1 Consumer expectations 1.3.2 Product attributes 1.3.3 Product specifications 1.3.4 New Product Design Product Shelf Life 1.5.1 Studying shelf life 1 S.2 Storage and Distribution Design Food Processing Reaction Technology Base 1.7.1 1.7.2 Process control 1.7.3 Food Process Design Modelling Food Processing Using Reaction Technology The Challenge References Sensitivity of product attributes to processing conditions Extending product shelf life Process variables and their variability Ensuring product quality and safety in food processing 2. PRODUCT CHANGES DURING PROCESSING 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 Introduction Reactions in Food Materials During Processing Time and Temperature in Food Processing Concentration Sensitivity 2.4.1 2.4.2 2.4.3 Rate equations Temperature Sensitivity 2.5.1 2.5.2 Sensitivity to processing temperature Reaction RateITemperature Relationships: Activation Energies Reaction Rate/Temperature Relationships: Other Temperature Coefficients Reaction RateKoncentration Relationships 2.8.1 First order reactions 2.8.2 Zero order reactions 2.8.3 Other ratehoncentration relationships Relative Extents of Food Processing Reactions Practicalities 2.10.1 2.10.2 2.10.3 Studying temperature coefficients Rate of change proportional to concentration Time needed to reach a particular concentration Relationship between reaction rate and temperature Studying change in concentration with time Studying rate of reactionhemperature relationships 1 1 2 4 4 4 5 8 10 12 13 16 17 18 19 21 22 24 25 28 30 32 32 33 35 36 36 37 41 43 43 47 49 52 56 56 57 60 62 69 69 70 71 ... 111 2.10.4 Time patterns 2. I 1 References 71 71 3. PROCESSING OUTCOMES 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Introduction Steady Conditions of Time and Temperature Variable Conditions of Time and Temperature 3.3.1 3.3.2 Space and timehemperature Microbiological Outcomes from Process Reactions 3.4.1 Microbial growth 3.4.2 Microbial death Process Integration 3.5.1 General principles 3.5.2 3.5.3 Shelf-lives of frozen foods Practicalities 3.6.1 Designing the process 3.6.2 Controlling the process 3.6.3 Benefits of outcome/time-temperature charts 3.6.4 References Sequential changes in temperature with time Steri I i sationkanni ng Relating outcomes to process conditions 4. ACHIEVING BETTER FOOD PRODUCTS 4.1 Introduction 4.2 Changing Reaction Rates 4.2.1 Changes in temperature 4.2.2 Enzymic-catalysed reactions 4.3 Sequential (Chain) Reactions 4.4 Parallel Sets of Reactions 4.5 More Complex Situations 4.6 Process Optimisation 4.7 Processing in Continuous Systems 4.8 Practicalities 4.8.1 Examining constituents and attributes 4.8.2 Improving existing processes 4.8.3 4.9 References Application to new product design and process development 5. BROADENING THE NET 5.1 5.2 5.3 5.4 5.5 Introduction Processing Agents 5.2.1 Additives 5.2.2 Modified atmospheres 5.2.3 Water activity Alternative Energy Processing Conditions 5.3.1 Irradiation 5.3.2 Electrical and magnetic fields 5.3.3 Very high pressures Combined Process Technology and the Total Process 5.4.1 Hurdle technology 5.4.2 Sous vide 5.4.3 Total Process technology Some Successes of Applied Reaction Technology 5.5.1 Canning 5.5.2 Continuous processing 5.5.3 Meat freezing 73 73 73 78 78 81 83 83 87 88 88 89 94 103 104 104 105 106 106 109 109 110 110 113 117 122 127 129 136 139 139 140 141 142 144 144 145 146 148 150 152 153 156 158 159 160 161 163 164 164 164 165 iv 5.5.4 New ingredients from milk 5.5.5 Fresher fruit for the consumer 5.5.6 Food ingredients modification 5.5.7 Storage lives 5.5.8 Packaging 5.6.1 Quantitative product attribute measurement 5.6.2 Temperature control 5.6.3 Measurement of process extent 5.7.1 More uniform product quality 5.7.2 Nutritional enhancement 5.7.3 Safety 5.7.4 5.7.5 Technological skills 5.7.6 Instrumentation and automation 5.7.7 Optimisation 5.7.8 5.7.9 New food products 5.8 References 5.6 Practicalities 5.7 Opportunities for the Future Better and more effective regulation An enhanced basis for food reaction technology