Thermal Food Engineering Operations

Preface xvii 1 Novel Thermal Technologies: Trends and Prospects 1 Amrita Preetam, Vipasha, Sushree Titikshya, Vivek Kumar, K.K Pant and S N Naik 1.1 Introduction 1 1.2 Novel Thermal Technologies: Current Status and Trends 3 1.2.1 Environmental Impact of Novel Thermal Technologies 6 1.2.2 The Objective of Thermal Processing 8 1.2.3 Preservation Process 9 1.3 Types of Thermal Technologies 11 1.3.1 Infrared Heating 12 1.3.1.1 Principal and Mechanism 12 1.3.1.2 Advantages of IR Heating 13 1.3.1.3 Applications of IR Heating 14 1.3.2 Microwave Heating 14 1.3.2.1 Principal and Mechanism 14 1.3.2.2 Advantages of Microwave in Food Industry 17 1.3.2.3 Application of Microwave in Food Processing Technologies 19 1.3.3 Radiofrequency (RF) Heating 24 1.3.3.1 Principal and Mechanism 24 1.3.3.2 Advantages and Disadvantages 26 1.3.3.3 Applications 27 1.3.4 Ohmic Heating 28 1.3.4.1 Principal and Mechanism 28 1.3.4.2 Advantages and Disadvantages 31 1.3.4.3 Applications 33 1.4 Future Perspective of Novel Thermal Technologies 36 1.5 Conclusion 36 References 37 2 Microbial Inactivation with Heat Treatments 45 Sushree Titikshya, Monalisa Sahoo, Vivek Kumar and S.N Naik 2.1 Introduction 45 2.2 Innovate Thermal Techniques for Food Reservation 47 2.3 Inactivation Mechanism of Targeted Microorganism 48 2.3.1 Action Approach and Inactivation Targets 49 2.4 Environmental Stress Adaption 50 2.4.1 Sublethal Injury 50 2.5 Resistance of Stress 51 2.5.1 Oxidative Stress 51 2.5.2 Osmotic Stress 52 2.5.3 Pressure 52 2.6 Various Techniques for Thermal Inactivation 52 2.6.1 Infrared Heating 52 2.6.1.1 Principle and Mechanism 52 2.6.1.2 Application for Inactivation in Food Sector 53 2.6.2 Microwave Heating 57 2.6.2.1 Principle and Mechanism 57 2.6.2.2 Application for Inactivation in Food Sector 58 2.6.3 Radiofrequency Heating 59 2.6.3.1 Principle and Mechanism 59 2.6.3.2 Application for Inactivation in Food Sector 60 2.6.4 Instant Controlled Pressure Drop Technology (DIC) 60 2.6.4.1 Principle and Mechanism 60 2.6.4.2 Application for Inactivation in Food Sector 61 2.6.5 Ohmic Heating 62 2.6.5.1 Principle and Mechanism 62 2.6.5.2 Application for Inactivation in Food Sector 63 2.7 Forthcoming Movements of Thermal Practices in Food Industry 64 2.8 Conclusion 65 References 66 3 Blanching, Pasteurization and Sterilization: Principles and Applications 75 Monalisa Sahoo, Sushree Titikshya, Pramod Aradwad, Vivek Kumar and S N Naik 3.1 Introduction 76 3.2 Blanching: Principles & Mechanism 76 3.2.1 Types of Blanching 76 3.2.1.1 Hot Water Blanching 76 3.2.1.2 Steam Blanching 80 3.2.1.3 High Humidity Hot Air Impingement Blanching (HHAIB) 81 3.2.1.4 Microwave Blanching 81 3.2.1.5 Ohmic Blanching 85 3.2.1.6 Infrared Blanching 86 3.2.2 Application of Blanching 89 3.2.2.1 Inactivation of Enzymes 89 3.2.2.2 Enhancement of Product Quality and Dehydration 90 3.2.2.3 Toxic and Pesticides Residues Removal 90 3.2.2.4 Decreasing Microbial Load 90 3.2.2.5 Reducing Non-Enzymatic Browning Reaction 91 3.2.2.6 Peeling 91 3.2.2.7 Entrapped Air Removal 91 3.2.2.8 Enhancing Bioactive Extraction Efficiency 91 3.2.2.9 Other Applications 92 3.3 Pasteurization: Principles & Mechanism 92 3.3.1 Thermal Pasteurization 92 3.3.2 Traditional Thermal Pasteurization 93 3.3.3 Microwave and Radiofrequency Pasteurization 93 3.3.4 Ohmic Heating Pasteurization 94 3.3.5 Application of Pasteurization 98 3.4 Sterilization: Principles, Mechanism and Types of Sterilization 98 3.4.1 Conventional Sterilization Methods 99 3.4.2 Advanced Retorting 100 3.4.3 Microwave-Assisted Thermal Sterilization 101 3.4.4 Pressure-Assisted Thermal Sterilization 103 3.5 Conclusions 104 References 104 4 Aseptic Processing 117 Malathi Nanjegowda, Bhaveshkumar Jani and Bansee Devani 4.1 Introduction 118 4.2 Aseptic Processing 118 4.3 Principle of Thermal Sterilization 121 4.3.1 Effect of Thermal Treatment on Enzymes 123 4.3.2 Effect of Thermal Treatments on Nutrients and Quality 123 4.3.3 Effect of Thermal Treatments on the Cooking Index (C0) 124 4.3.4 Effect of Heat Treatments on Chemical Reactions in Food 124 4.4 Components of Aseptic Processing 124 4.4.1 Equipment Used in Aseptic/UHT Processing 124 4.4.1.1 Indirect Heat Exchanger 125 4.4.1.2 Direct Heat Exchanger 126 4.4.1.3 Ohmic Heating (OH) 126 4.5 Aseptic Packaging 127 4.5.1 Types of Packaging Materials Used in Aseptic Processing 127 4.5.2 Methods and Requirements of Decontamination of Packaging Materials 128 4.6 Applications of Aseptic Processing and Packaging 128 4.6.1 Milk Processing 133 4.6.2 Non-Milk Products Processing 135 4.7 Advantages of Aseptic Processing and Packaging 136 4.8 Challenges of Aseptic Processing and Packaging 137 4.9 Conclusion 137 References 138 5 Spray Drying: Principles and Applications 141 Sukirti Joshi, Asutosh Mohapatra, Lavika Singh and Jatindra K Sahu 5.1 Introduction 142 5.2 Concentration of Feed Solution 142 5.3 Atomization of Concentrated Feed 143 5.3.1 Principle of Atomization 143 5.3.2 Classification of Atomizers 143 5.3.2.1 Rotary Atomizers 144 5.3.2.2 Pressure Nozzle/Hydraulic Atomizer 144 5.3.2.3 Two‐Fluid Nozzle Atomizer 145 5.4 Droplet‐Hot Air Contact 145 5.5 Drying of Droplets 146 5.6 Particle Separation 148 5.7 Effect of Process Parameters on Product Quality 148 5.7.1 Process Parameters of Atomization 150 5.7.2 Parameters of Spray‐Air Contact and Evaporation 151 5.7.2.1 Spray Angle 151 5.7.2.2 Aspirator Flow Rate 151 5.7.2.3 Inlet Air Temperature 151 5.7.2.4 Outlet Air Temperature 152 5.7.2.5 Glass Transition Temperature 152 5.7.2.6 Residence Time 153 5.8 Classification of Spray Dryer 153 5.8.1 Open-Cycle Spray Dryer 153 5.8.2 Closed-Cycle Spray Dryer 154 5.8.3 Semi‐Closed Cycle Spray Dryer 154 5.8.4 Single‐Stage Spray Dryer 154 5.8.5 Two‐Stage Spray Dryer 154 5.8.6 Short‐Form Spray Dryer 154 5.8.7 Tall‐Form Spray Dryer 154 5.9 Morphological Characterization of Spray-Dried Particles 155 5.10 Application of Spray Drying for Foods 156 5.11 Wall Materials 157 5.11.1 Carbohydrate-Based Wall Materials 158 5.11.1.1 Starch 158 5.11.1.2 Modified Starch 158 5.11.1.3 Maltodextrins 158 5.11.2 Cyclodextrins 159 5.11.3 Gum Arabic 159 5.11.4 Inulin 159 5.11.5 Pectin 160 5.11.6 Chitin and Chitosan 160 5.11.7 Protein-Based Wall Materials 160 5.11.7.1 Whey Protein Isolate 161 5.11.7.2 Skim Milk Powder 161 5.11.7.3 Soy Protein Isolate (SPI) 161 5.12 Encapsulation of Probiotics 162 5.12.1 Choice of Bacterial Strain 162 5.12.2 Response to Cellular Stresses 163 5.12.3 Growth Conditions 164 5.12.4 Effect of pH 164 5.12.5 Harvesting Technique 165 5.12.6 Total Solid Content of the Feed Concentrate 165 5.13 Encapsulation of Vitamins 165 5.14 Encapsulation of Flavours and Volatile Compounds 166 5.14.1 Selective Diffusion Theory 166 5.15 Conclusion and Perspectives 170 References 170 6 Solar Drying: Principles and Applications 179 Baher M A Amer 6.1 Introduction 179 6.2 Principle of Solar Drying 180 6.3 Construction of Solar Dryer 181 6.4 Historical Classification of Solar Energy Drying Systems 182 6.5 Storing Solar Energy for Drying 185 6.6 Hybrid/Mixed Solar Drying System 186 6.7 Solar Greenhouse Dryer 188 6.8 Solar Drying Economy 188 6.9 New Applications Related to Solar Drying 190 References 192 7 Fluidized Bed Drying: Recent Developments and Applications 197 Praveen Saini, Nitin Kumar, Sunil Kumar and Anil Panghal 7.1 Introduction 197 7.2 Principle and Design Considerations of Fluidized Bed Dryer 198 7.2.1 Spouted Bed Dryer 201 7.2.2 Spout Fluidized Bed Dryer 202 7.2.3 Hybrid Drying Techniques 205 7.2.3.1 Microwave-Assisted FBD 205 7.2.3.2 FIR-Assisted FBD 206 7.2.3.3 Heat Pump–Assisted FBD 207 7.2.3.4 Solar-Assisted FBD 207 7.3 Design Alterations for Improved Fluidization Capacity 208 7.3.1 Vibrated Fluidized Bed 208 7.3.2 Agitated Fluidized Bed 209 7.3.3 Centrifugal Fluidized Bed 210 7.4 Energy Consumption in Fluidized Bed Drying 211 7.5 Effect of Fluidized Bed Drying on the Quality 212 7.6 Applications of Fluidized Bed Drying 215 7.7 Concluding Remarks 215 References 215 8 Dehumidifier Assisted Drying: Recent Developments 221 Vaishali Wankhade, Vaishali Pande, Monalisa Sahoo and Chirasmita Panigrahi 8.1 Introduction 221 8.2 Absorbent Air Dryer 222 8.2.1 Working Principle of Adsorption Air Dryer 223 8.2.2 Design Considerations and Components of the Absorbent Air Drier 223 8.2.2.1 Desiccant Drying System 223 8.2.3 Performance Indicators of Desiccant Air Dryer System 226 8.2.3.1 Low Temperature Drying With No Temperature Control and Air Circulation System 227 8.2.3.2 Low Temperature Drying With Air Circulation and Temperature Control 228 8.3 Heat Pump–Assisted Dehumidifier Dryer 228 8.3.1 Working Principles of a Heat Pump–Assisted Dehumidifier Dryer 229 8.3.2 Performance Indicators of Heat Pump–Assisted Dehumidifier Dryer 231 8.4 Applications of Dehumidifier-Assisted Dryers in Agriculture and Food Processing 233 8.5 Concluding Remarks 234 References 234 9 Refractance Window Drying: Principles and Applications 237 Peter Waboi Mwaurah, Modiri Dirisca Setlhoka and Tanu Malik 9.1 Introduction 238 9.2 Refractance Window Drying System 239 9.2.1 History and Origin 239 9.2.2 Components and Working of the Dryer 240 9.2.3 Principle of Operation 242 9.3 Heat Transfer and Drying Kinetics 244 9.3.1 Drying Rate and Moisture Reduction Rate 245 9.4 Effect of Process Parameters on Drying 245 9.4.1 Effect of Temperature of the Hot Circulating Water 245 9.4.2 Effect of Product Inlet Temperature and Thickness 246 9.4.3 Effect of Residence Time 247 9.4.4 Effect of Ambient Air Temperature (Air Convection) 247 9.5 Comparison of Refractance Window Dryer with Other Types of Dryers 247 9.6 Effect of Refractance Window Drying on Quality of Food Products 248 9.6.1 Effects on Food Color 249 9.6.2 Effects on Bioactive Compounds 250 9.6.2.1 Carotene Retention 251 9.6.2.2 Ascorbic Acid Retention 252 9.6.2.3 Anthocyanin Retention 252 9.7 Applications of Refractance Window Drying in Food and Agriculture 253 9.7.1 Applications of Refractance Window Drying in Preservation of Heat-Sensitive and Bioactive Compounds 253 9.7.2 Applications of Refractance Window Drying on Food Safety 254 9.8 Advantages and Limitations of Refractance Window Dryer 255 9.9 Recent Developments in Refractance Window Drying 255 9.10 Conclusion and Future Prospects 256 References 257 10 Ohmic Heating: Principles and Applications 261 Sourav Misra, Shubham Mandliya and Chirasmita Panigrahi 10.1 Introduction 261 10.2 Basic Principles 263 10.3 Process Parameters 265 10.3.1 Electrical Conductivity 265 10.3.2 Electrical Field Strength 266 10.3.3 Frequency and Waveform 267 10.3.4 Product Size, Viscosity, and Heat Capacity 267 10.3.5 Particle Concentration 267 10.3.6 Ionic Concentration 267 10.3.7 Electrodes 268 10.4 Equipment Design 268 10.5 Application 270 10.5.1 Blanching 276 10.5.2 Pasteurisation/Sterilization 276 10.5.3 Extraction 277 10.5.4 Dehydration 278 10.5.5 Fermentation 279 10.5.6 Ohmic Thawing 280 10.6 Effect of Ohmic Heating on Quality Characteristics of Food Products 280 10.6.1 Starch and Flours 280 10.6.1.1 Water Absorption Index (WAI) and Water Solubility Index (WSI) 280 10.6.1.2 Pasting Properties 280 10.6.1.3 Thermal Properties 281 10.6.2 Meat Products 282 10.6.3 Fruits and Vegetable Products 282 10.6.3.1 Electrical Properties 282 10.6.3.2 Soluble Solids Content and Acidity 282 10.6.3.3 Vitamins 283 10.6.3.4 Flavor Compounds 284 10.6.3.5 Phenolic Compounds 284 10.6.3.6 Colour Properties 284 10.6.3.7 Change in Chlorophyll Content 285 10.6.3.8 Textural Properties 285 10.6.3.9 Sensory Properties 286 10.6.4 Dairy Products 286 10.6.5 Seafoods 290 10.7 Advantages of Ohmic Heating 290 10.8 Disadvantages of Ohmic Heating 291 10.9 Conclusions 291 References 292 11 Microwave Food Processing: Principles and Applications 301 Jean-Claude Laguerre and Mohamad Mazen Hamoud-Agha 11.1 Introduction 301 11.2 Principles of Microwave Heating 302 11.2.1 Nature of Microwaves 302 11.2.1.1 Propagation of EM Waves in Free Space 302 11.2.1.2 Propagation of EM Waves in Matter 306 11.2.2 Mechanism of Microwave Heating 309 11.2.2.1 Dielectric Characteristic of a Material 309 11.2.2.2 Waves-Product Interactions 312 11.2.3 Transmission and Absorption of a Wave in a Material 316 11.2.3.1 Expression of Transmitted Power 316 11.2.3.2 Penetration Depths 317 11.2.3.3 Power Dissipation 319 11.3 Applications 320 11.3.1 Microwave Baking 320 11.3.2 Microwave Blanching 323 11.3.3 Microwave Tempering and Thawing 326 11.3.4 Microwave Drying 328 11.3.4.1 Microwave-Assisted Hot Air Drying 329 11.3.4.2 Microwave-Assisted Vacuum Drying 330 11.3.4.3 Microwave-Assisted Freeze-Drying 330 11.3.5 Microwave Pasteurization and Sterilization 331 References 334 12 Infrared Radiation: Principles and Applications in Food Processing 349 Puneet Kumar, Subir Kumar Chakraborty and Lalita 12.1 Introduction 350 12.2 Mechanism of Heat Transfer 351 12.2.1 Principles of IR Heating 351 12.2.1.1 Planck’s Law 352 12.2.1.2 Wien’s Displacement Law 352 12.2.1.3 Stefan–Boltzmann’s Law 352 12.2.2 Source of IR Radiations 353 12.2.2.1 Natural Source 354 12.2.2.2 Artificial Sources 354 12.3 Factors Affecting the Absorption of Energy 356 12.3.1 Characteristics of Food Materials 357 12.3.1.1 Composition 357 12.3.1.2 Layer Thickness 357 12.3.2 IR Parameters 357 12.3.2.1 Wavelength of IR Rays 358 12.3.2.2 IR Intensity 358 12.3.2.3 Depth of Penetration 358 12.3.3 Advantages of IR Heating Over Conventional Heating Methods 359 12.4 Applications of IR in Food Processing 359 12.4.1 Drying 360 12.4.2 Peeling 361 12.4.3 Blanching 363 12.4.4 Microbial Decontamination 364 12.5 IR-Assisted Hybrid Drying Technologies 366 12.5.1 IR-Freeze-Drying 366 12.5.2 Hot Air-Assisted IR Heating 367 12.5.3 Low-Pressure Superheated Steam Drying with IR 368 12.6 Conclusion 368 References 369 13 Radiofrequency Heating 375 Chirasmita Panigrahi, Monalisha Sahoo, Vaishali Wankhade and Siddharth Vishwakarma 13.1 Introduction 376 13.2 History of RF Heating 377 13.3 Principles and Equipment 378 13.3.1 Basic Mechanism of Dielectric Heating 378 13.3.1.1 Basic Mechanism and Working of Radiofrequency Heating 379 13.3.1.2 Basic Mechanism and Working of Microwave Heating 380 13.3.2 Factors of Food Affecting the Performance of RF Processing 380 13.3.2.1 Permittivity and Loss Factor 380 13.3.2.2 Power Density and Penetration Depth 381 13.3.2.3 Wave Impedance and Power Reflection 382 13.3.3 Comparison of RF Heating With Other Methods 383 13.3.4 Lab Scale and Commercial Scale of RF Equipment 385 13.3.4.1 Radiofrequency Processing of Food at Lab Scale 386 13.3.4.2 Radiofrequency Processing of Food at Industrial Scale 387 13.4 Applications in Food Processing 388 13.4.1 Drying 388 13.4.2 Thawing 393 13.4.3 Roasting 394 13.4.4 Baking 394 13.4.5 Disinfestation 395 13.4.6 Blanching 395 13.4.7 Pasteurization/Sterilization 396 13.5 Technological Constraints, Health Hazards, and Safety Aspects 399 13.6 Commercialization Aspects and Future Trends 402 13.7 Conclusions 404 References 404 14 Quality, Food Safety and Role of Technology in Food Industry 415 Nartaj Singh and Prashant Bagade 14.1 Introduction 416 14.1.1 Food Quality 417 14.1.1.1 Primary and Secondary Food Processing 419 14.1.1.2 Historical Trends in Food Quality 421 14.1.1.3 Food Quality Standards and its Requirements 423 14.1.1.4 Role of Technology in Building Food Quality Within the Industry 440 14.1.1.5 Regulations and their Requirements 444 14.1.2 Food Safety 445 14.1.2.1 Primary and Secondary Food Production 445 14.1.2.2 Historical Trends in Food Safety 446 14.1.2.3 Food Safety Standards and its Requirements 447 14.1.2.4 Role of Technology in Building Food Safety Within Industry 450 14.2 Future Trends in Quality and Food Safety 451 14.3 Conclusion 453 References 453 Index 455