Introduction to Food Engineering (eBook)

Cover 1
Emerging Technologies for Food Processing 4
Contents 6
About the Editor 14
Contributors 16
Preface 19
Part 1 High Pressure Processing 20
1. High Pressure Processing of Foods: An Overview 22
1 Introduction 22
2 Principles of high pressure processing 23
2.1 Background 23
2.2 Description of the process 24
2.3 Process principles 26
2.4 Packaging requirements 27
2.5 Current commercial status of high pressure processing 28
3 Use of high pressure to improve food safety and stability 28
3.1 Effect of high pressure on microorganisms 29
3.1.1 Bacteria 29
3.1.2 Bacterial spores 31
3.1.3 Fungi 31
3.1.4 Viruses 32
3.1.5 Prions 32
3.2 Factors influencing microbial sensitivity to high pressure 33
3.2.1 pH 33
3.2.2 Water activity (a[sub(w)]) 33
3.2.3 Temperature, pressure and holding time 34
3.3 High pressure regulations 34
4 Effects of high pressure on food quality 35
4.1 Effect of high pressure on food colour 36
4.2 Effect of high pressure on food texture 36
4.3 Effect of high pressure on food sensory quality 37
4.4 Effect of high pressure on food yield 37
5 Other applications of high pressure 39
5.1 High pressure freezing applications 39
5.2 High pressure thawing 41
5.3 High pressure non-frozen storage 41
6 Modelling HP processes 42
6.1 Modelling high pressure processes 42
6.2 Modelling high pressure freezing processes 43
7 Outlook for high pressure processing of food 44
8 Conclusions 46
References 46
2. High-pressure Processing of Salads and Ready Meals 52
1 Introduction 52
2 Importance of salads and ready meals 53
3 Pressure effects on microorganisms 54
3.1 Efficacy of microbial inactivation in HPP processed ready meals 54
3.2 Efficacy of microbial inactivation in HPP-processed dips, sauces and salad dressings 56
4 Pressure effects on enzyme activity 56
4.1 Effect of high pressure on enzyme activity of fruits and vegetables 57
4.2 Effect of high pressure on enzyme activity in meats 58
5 Pressure effects on texture 58
5.1 Textural changes in pressure treated ready meals 58
5.2 Textural changes in pressure-treated dips, sauces and salad dressings 60
6 Pressure effects on nutrients 61
7 Conclusions 61
Acknowledgement 62
References 62
3. Microbiological Aspects of High-pressure Processing 66
1 Introduction 66
2 Factors affecting effectiveness of treatment 67
2.1 Types of organisms 67
2.2 Food products 68
2.3 Conditions of treatments 71
2.4 Combined treatments 73
3 Effects of high pressure 75
3.1 Bacterial and fungal cells 75
3.1.1 Morphology 75
3.1.2 Cell wall and membrane 76
3.1.3 Biochemical reactions 77
3.1.4 Genetic mechanisms 77
3.2 Bacterial spores 77
3.3 Parasites 78
3.4 Viruses 78
4 Conclusions 79
References 79
Part 2 Pulsed Electric Fields Processing 86
4. Overview of Pulsed Electric Field Processing for Food 88
1 Introduction 88
2 Historical background 89
3 Mechanisms of action 91
4 PEF treatment systems 93
4.1 Generation of pulsed electric fields 94
4.2 Treatment chamber design 96
5 Main processing parameters 98
5.1 Electric field strength 98
5.2 Treatment time, specific energy and pulse geometry 99
5.3 Treatment temperature 100
5.4 Treatment medium factors 100
5.4.1 Conductivity 101
5.4.2 Effect of air bubbles and particles 101
5.5 Cell characteristics 101
6 Applications 102
6.1 Stress induction 102
6.2 Disintegration of biological material 103
6.3 Preservation of liquid media 105
7 Problems and challenges 108
8 Conclusions 109
Acknowledgements 109
Nomenclature 110
References 110
5. Pulsed Electric Field Processing of Liquid Foods and Beverages 118
1 Introduction 118
2 PEF technology 120
3 Mechanisms of microbial inactivation 122
4 Equipment 124
4.1 Batch treatment system 125
4.2 Continuous treatment system 126
5 PEF treatment variables 128
5.1 PEF system variables 128
5.2 Medium parameters 131
5.2.1 pH Effect 131
5.2.2 Temperature effect 132
5.2.3 Composition effect 133
5.2.4 Antimicrobials 133
5.2.5 Ionic effect 135
6 Target differences 135
7 High-pressure processing (HPP) and PEF 137
8 Specific results on liquid foods 138
8.1 Milk 138
8.2 Liquid whole egg and egg white 139
8.3 Apple cider and juice 140
8.4 Orange juice 141
8.5 Tomato juice 143
8.6 Red grape juice 143
8.7 Mango juice 144
8.8 Cranberry juice 145
8.9 Beer 145
8.10 Rice wine (yakju) 145
9 Process models 145
9.1 Energy and power 145
9.2 Microbial inactivation models 146
9.3 Process temperature 147
10 Conclusions 147
Acknowledgements 149
Nomenclature 149
References 150
6. Effect of High Intensity Electric Field Pulses on Solid Foods 160
1 Introduction 160
2 Food safety 162
3 Effects on food quality 163
3.1 Effects on proteins and enzyme activity 163
3.2 Effects on texture and microstructure 165
4 Use of PEF in combination with other methods 167
5 Conclusions 168
References 168
7. Enzymatic Inactivation by Pulsed Electric Fields 174
1 Introduction 174
2 Mechanism of enzyme inactivation by PEF 176
3 Factors affecting enzyme inactivation by PEF 177
3.1 PEF processing factors 177
3.2 Enzyme characteristics 179
3.3 Product parameters 179
4 Effects of PEF on enzymes 180
4.1 Pectin methyl esterase (PME) 182
4.2 Polygalacturonase (PG) 184
4.3 Polyphenoloxidase (PPO) 184
4.4 Peroxidase (POD) 185
4.5 Lipoxygenase (LOX) 186
4.6 Alkaline phosphatase (ALP) 186
4.7 Protease 187
4.8 Lipase 188
4.9 Other enzymes 189
5 Modelling enzymatic inactivation by PEF 189
6 Enzyme inactivation by combining PEF with other hurdles 193
7 Enzyme activity during storage of PEF processed foods 194
8 Conclusions 195
Nomenclature 195
References 196
8. Food Safety Aspects of Pulsed Electric Fields 202
1 Introduction 202
2 Microbiological safety of pulsed electric fields 204
2.1 Effect of PEF on microorganisms 204
2.2 Mechanism of microorganism inactivation by PEF 205
2.3 Factors affecting microbial inactivation by PEF 206
2.3.1 Process parameters 206
2.3.2 Microbial characteristics 208
2.3.3 Product parameters 208
2.4 Combination of PEF with other hurdles to inactivate microorganisms 210
2.5 Modelling the inactivation of microorganisms by PEF 212
2.6 Effect of PEF on pathogenic microorganisms 213
2.6.1 Escherichia coli 215
2.6.2 Listeria 217
2.6.3 Salmonella 218
2.6.4 Bacillus 219
2.6.5 Other pathogenic microorganisms 219
2.7 Effect of PEF on spoilage microorganisms 220
2.7.1 Lactobacillus 220
2.7.2 Saccharomyces 222
2.7.3 Other spoilage microorganisms 223
2.8 Shelf-life of foods processed by PEF 224
3 Chemical safety and PEF 225
4 Conclusions 226
Nomenclature 227
References 227
Part 3 Other Non-thermal Processing Techniques 238
9. Developments in Osmotic Dehydration 240
1 Introduction 240
2 Mechanism of osmotic dehydration 242
3 Effect of process parameters on mass transfer 245
4 Determination of moisture and solid diffusion coefficients 246
4.1 Infinite flat plate 246
4.2 Rectangular parallelepiped 247
4.3 Infinite cylinder 247
4.4 Finite cylinder 247
5 Methods to increase the rate of mass transfer 248
5.1 Application of high hydrostatic pressure 249
5.2 Application of high electric field pulse pre-treatment 249
5.3 Application of ultrasound during osmotic dehydration 252
5.4 Application of gamma-irradiation in osmotic dehydration 252
5.5 Application of vacuum during osmotic dehydration 253
5.6 Application of centrifugal force during osmotic dehydration 253
6 Applications of osmotic dehydration 254
6.1 Osmotic dehydration and air drying 254
6.2 Osmotic dehydration and freezing 255
6.3 Osmotic dehydration and frying 256
6.4 Osmotic dehydration and rehydration 257
6.5 Osmotic dehydration and jam manufacture 259
7 Limitations of osmotic dehydration 260
8 Management of osmotic solution 260
9 Conclusions 261
Nomenclature 262
References 262
10. Athermal Membrane Processes for the Concentration of Liquid Foods and Natural Colours 270
1 Introduction 270
2 Existing methods 271
2.1 Evaporative concentration 271
2.1.1 Open pan evaporators 271
2.1.2 Plate evaporators 272
2.1.3 Rising film evaporator 272
2.1.4 Falling film evaporator 272
2.1.5 Agitated thin-film evaporators 272
2.2 Freeze concentration 272
2.3 Membrane processes 273
2.3.1 Microfiltration 273
2.3.2 Ultrafiltration 274
2.3.3 Reverse osmosis 274
3 Osmotic membrane distillation 275
3.1 Fundamentals of osmotic membrane distillation 275
3.2 Mathematical models 276
3.2.1 Mass transfer 276
3.2.2 Mass transfer through the membrane 276
3.2.3 Mass transfer through the boundary layers 278
3.2.4 Heat transfer 278
3.2.5 Heat transfers through boundary layers 278
3.3 OMD membranes 279
3.4 Effect of various process parameters 280
3.4.1 Type of osmotic agent 280
3.4.2 Concentration 280
3.4.3 Flow rate 281
3.4.4 Temperature 281
3.4.5 Membrane pore size 281
3.5 Process design and economics 281
4 Direct osmosis 282
4.1 Fundamentals of direct osmosis 282
4.2 Mathematical models 283
4.2.1 Mass transfer through the membrane 283
4.3 DO membranes 285
4.4 Effect of various process parameters 285
4.4.1 Type of osmotic agent 285
4.4.2 Concentration 285
4.4.3 Temperature 286
4.4.4 Flow rate 286
4.4.5 Membrane thickness 286
4.5 Process design and economics 286
5 Membrane modules 287
6 Applications 288
6.1 OMD 288
6.2 DO 290
7 Suggestions for future work 290
8 Conclusions 291
Acknowledgements 292
Nomenclature 292
References 294
11. High Intensity Pulsed Light Technology 298
1 Introduction 298
2 Principles of pulsed light technology 299
3 Effects of pulsed light on food products 303
3.1 Effects of PL on microorganisms 303
3.2 PL process optimization 305
3.2.1 General considerations 305
3.2.2 Spectral distribution and treatment intensity 311
3.2.3 Time parameters 314
3.2.4 Target parameters 315
3.3 Effects of PL on enzymes and food properties 317
3.3.1 Enzymes 317
3.3.2 Nutritional properties 317
3.3.3 Sensory properties 317
4 Systems for pulsed light technology 318
4.1 Description of PL systems 318
4.2 Examples of PL experimental plants 319
5 Conclusions 321
Acknowledgements 322
Nomenclature 322
References 323
12. Non-thermal Processing by Radio Frequency Electric Fields 326
1 Introduction 326
2 Radio frequency electric fields equipment 328
3 Modelling of radio frequency electric fields 332
4 RFEF non-thermal inactivation of yeast 333
5 Bench scale RFEF inactivation of bacteria and spores 334
6 Pilot scale RFEF inactivation of bacteria 336
7 Electrical costs 338
8 Conclusions 338
Acknowledgements 339
References 339
13. Application of Ultrasound 342
1 Introduction 342
2 Fundamentals of ultrasound 344
2.1 The physics and chemistry of ultrasound 344
2.1.1 Power ultrasound in liquid systems 344
2.1.1.1 Homogeneous liquid-phase systems 344
2.1.1.2 Solid–liquid systems 345
2.1.1.3 Liquid–liquid systems 345
2.1.2 Power ultrasound in gases 345
2.2 Ultrasonic processing equipment 346
2.2.1 Laboratory scale 346
2.2.2 Large scale 346
2.2.2.1 Batch systems 347
2.2.2.2 Flow systems 348
3 Ultrasound as a food preservation tool 348
3.1 Inactivation of microorganisms 349
3.2 Inactivation of enzymes 351
4 Ultrasound as a processing aid 352
4.1 Mixing and homogenization 352
4.2 Foam formation and destruction 353
4.3 Precipitation of airborne powders 355
4.4 Filtration and drying 357
4.4.1 Filtration 357
4.4.2 Drying 357
4.5 Extraction 359
5 Ultrasound effects on food properties 361
5.1 Effects of ultrasound on dairy products 361
5.2 Effects of ultrasound on juices 362
5.3 Effects of ultrasound on egg products 363
6 Conclusions 363
References 364
14. Irradiation of Foods 372
1 Introduction 372
1.1 Importance of food-borne illness 372
2 Fundamentals of food irradiation 375
2.1 Definition 375
2.2 Doses of irradiation 376
3 Wholesomeness of irradiated foods 377
3.1 Government regulations 377
3.2 Public acceptance 380
4 Biological effects of irradiation 382
4.1 Effects on microorganisms 382
4.2 Effects on parasites and insects 383
4.3 Effects on viruses 386
4.4 Effect on ripening delay 386
4.5 Sprouting inhibition 386
5 Irradiation of foods 387
5.1 Irradiation of fresh fruit and vegetables 387
5.2 Irradiation of fish, meat and poultry 388
5.3 Use of combined treatments 388
5.3.1 Application on fruit and vegetables 389
5.3.2 Application on poultry, meat and fish 391
6 Conclusions 396
References 397
15. New Chemical and Biochemical Hurdles 406
1 Introduction 406
2 Organic acids 407
2.1 Acetic acid 408
2.2 Propionic acid 409
2.3 Lactic acid 410
2.4 Sorbic acid 411
2.5 Benzoic acid 411
2.6 Parabens 412
2.7 Citric acid 412
2.8 Malic acid 413
2.9 Fumaric acid 413
2.10 Tartaric and adipic acid 414
2.11 GdL 414
2.12 Long chain fatty acids and phenolic acids 414
3 Plant-derived antimicrobials 415
4 Chitin/chitosan 418
5 Antimicrobial enzymes 420
5.1 Lysozyme 420
5.2 Glucose oxidase 421
5.3 Lactoperoxidase 422
5.4 Other oxidoreductases 422
6 Nisin 423
7 Lactoferrin 424
8 Ozone 425
9 Reuterin 425
10 Electrolysed water and other concepts 426
11 Discussion 426
12 Conclusions 428
References 429
Part 4 Alternative Thermal Processing 436
16. Recent Developments in Microwave Heating 438
1 Introduction 438
2 Dielectric properties of foods 439
3 Heat and mass transfer in microwave processing 442
4 Microwave processing of foods 445
4.1 Microwave baking 446
4.2 Microwave drying 448
4.3 Microwave thawing and tempering 451
4.4 Microwave pasteurization and sterilization 452
4.5 Microwave roasting 454
4.6 Microwave blanching 454
4.7 Future developments in microwave processing 455
5 Conclusions 456
Nomenclature 456
References 457
17. Radio-Frequency Processing 464
1 Introduction 464
2 Dielectric heating 465
2.1 Difference between radio frequency and microwaves 466
2.2 Heating mechanism of RF 467
3 Material properties 470
4 Adopting RF heating 472
4.1 The standardized 50 & #937
4.2 Design of a simple applicator 474
5 Radio-frequency heating applications 476
5.1 Thermal treatment of food products 477
5.2 Seed treatments 479
5.3 Product disinfestation or disinfection 479
6 Radio-frequency drying applications 480
6.1 Wood drying 480
6.2 Agricultural product drying 481
6.3 Food drying 481
7 Conclusions 482
Nomenclature 482
References 483
18. Ohmic Heating 488
1 Introduction 488
2 Fundamentals of ohmic heating 489
2.1 Basic principles 489
2.2 Electrical heat generation 491
3 Electrical conductivity 493
4 Generic configurations 495
4.1 Batch configuration (Figure 18.3a) 495
4.2 Transverse ohmic heating (Figure 18.3b) 496
4.3 Collinear ohmic heating (Figure 18.3c) 497
4.4 Technical considerations 498
5 Modelling 498
5.1 Treatment of non-Newtonian liquid 498
5.2 Treatment of solid/liquid mixtures 502
5.2.1 Electrical heat generation 503
5.2.2 Mass conservation 503
5.2.3 Heat transfer 504
5.2.3.1 Reference temperature 504
5.2.3.2 Energy equation 504
5.2.3.3 Liquid-solid heat transfer coefficient 505
5.2.4 Effects of parameters 505
5.2.4.1 Slip velocity effect 505
5.2.4.2 Volume fraction effect 507
5.2.4.3 Particle diameter effect 507
5.2.4.4 Electrical conductivity effect 507
6 Treatment of products 508
6.1 Product suitability – formulation and pre-treatment 508
6.2 Thermal treatments 511
6.2.1 Stabilization 511
6.2.1.1 Quantification of lethal effect 511
6.2.1.2 Mechanisms of microbial lethality 512
6.2.2 Cooking 513
6.2.3 Thawing 513
6.2.4 Blanching 513
6.2.5 Evaporation 514
6.3 Pre-treatment on mass-transfer operations 514
6.3.1 Diffusion and extraction 515
6.3.2 Dehydration 515
6.4 On-line treatment validation 515
6.5 Other aspects 516
7 Conclusions 517
Nomenclature 518
References 519
19. Combined Microwave Vacuum-drying 526
1 Introduction 526
2 Microwaves 528
3 Dielectric properties of food 530
4 Thermal properties of food 531
5 Characteristics of microwave vacuum-drying 531
5.1 Drying rate 532
5.2 Quality attributes of microwave vacuum-dried products 534
5.2.1 Rehydration potential 534
5.2.2 Texture modification 535
5.2.3 Retention of chemical components 536
5.3 Dehydration costs 538
6 Combination of microwave vacuum with other processes 540
7 Equipment 541
7.1 Commercial microwave vacuum-driers 541
7.2 Research microwave vacuum-driers 542
8 Modelling of microwave vacuum-drying 542
9 Microwave freeze-drying 543
10 Other applications of microwave vacuum processing 544
10.1 Tempering and thawing 545
10.2 Enzymes and microorganisms 545
11 Commercial potential 546
12 Conclusions 546
Nomenclature 547
References 547
20. New Hybrid Drying Technologies 554
1 Introduction 554
2 Product quality degradation during dehydration 556
3 Hybrid drying systems 556
3.1 Heat pump drying 557
3.2 Fluidized bed drying 560
3.3 Radio-frequency drying 562
3.4 Microwave drying 563
3.5 Novel drying technologies 565
3.5.1 Combined microwave and superheated steam drying 566
3.5.2 Pressure regulating drying 566
3.5.3 Rotating jet spouted bed 567
4 Conclusions 568
References 568
21. Monitoring Thermal Processes by NMR Technology 572
1 Introduction 572
2 Basic theory of NMR and MRI 573
2.1 Nuclear spins and energy levels 573
2.1.1 Precession and net magnetization vector 575
2.1.2 RF pulses 575
2.2 Relaxation 576
2.3 Chemical shift 576
2.4 Detection and Fourier transformation 578
2.5 Pulse sequences 578
2.5.1 Free induction decay – FID 578
2.5.2 Measurement of relaxation times 578
2.5.3 Diffusion-editing 579
2.5.4 Water suppression 580
2.6 Magnetic resonance imaging 580
2.6.1 MRI pulse sequences 581
2.7 NMR and MRI instruments 581
2.8 NMR and multivariate data analysis 582
3 NMR and thermal processes 583
3.1 Rheo-NMR 583
3.2 NMR and MRI baking 584
3.3 Cooking with NMR 586
3.4 MRI freezing 588
4 Future directions for process NMR 589
5 Conclusions 590
Nomenclature 590
References 591
Part 5 Innovations in Food Refrigeration 596
22. Vacuum Cooling of Foods 598
1 Introduction 598
2 Vacuum cooling principles, process and equipment 599
2.1 Vacuum cooling principles 599
2.2 Vacuum cooling process 600
2.3 Vacuum cooling equipment 600
3 Applications of vacuum cooling in the food industry 603
3.1 Fruit and vegetables 603
3.2 Bakery products 605
3.3 Fishery products 606
3.4 Sauces, soups and particulate foods 606
3.5 Large cooked meat joints 607
3.6 Ready meals 609
4 Mathematical modelling of the vacuum cooling process 610
4.1 Mathematical modelling of vacuum cooling of liquid food 610
4.2 Mathematical modelling of vacuum cooling of cooked meats 610
5 Advantages and disadvantages of vacuum cooling 611
5.1 Advantages of vacuum cooling 611
5.2 Disadvantages of vacuum cooling 613
6 Factors affecting the vacuum cooling process 614
6.1 Factors affecting vacuum cooling rate 614
6.2 Factors affecting product/produce temperature distribution 615
6.3 Factors affecting vacuum cooling loss 615
7 Conclusions 616
Nomenclature 616
References 617
23. Ultrasonic Assistance of Food Freezing 622
1 Introduction 622
2 Power ultrasound generation and equipment 623
2.1 Basic components required for power ultrasound generation 623
2.1.1 Power generator 623
2.1.2 Ultrasound transducers 624
2.2 Some common power ultrasonic systems 626
2.2.1 Ultrasonic bath 626
2.2.2 Ultrasonic probe system 626
2.2.3 Air-borne power ultrasonic system 627
3 Acoustic effects on the food freezing process 628
3.1 Acoustic effects on liquid, gas and solid 628
3.1.1 Acoustic effects on liquid 628
3.1.2 Acoustic effects on gas 630
3.1.3 Acoustic effects on solid 630
3.2 Acoustic effects on the freezing process 631
4 Major functions of power ultrasound in assisting food freezing 632
4.1 Initiation of ice nucleation 632
4.2 Acceleration of the freezing process 633
4.3 Control of the crystal size distribution in the frozen product 634
4.4 Improvement of frozen food microstructure 635
4.4.1 Effect of freezing on quality of frozen food 635
4.4.2 Influence of power ultrasound on the microstructure of frozen food 636
4.5 Preventing incrustation on a cold surface 636
5 Factors affecting power ultrasound efficiency 637
5.1 Acoustic power level 637
5.2 Acoustic duration 638
6 Embodiment of applications 639
6.1 Freezing of ice cream inside SSHE 639
6.2 Manufacture of moulded frozen products 641
6.3 Freezing and frozen storage of fresh foodstuffs 641
7 Conclusions 642
References 643
24. High-Pressure Freezing 646
1 Introduction 646
2 High-pressure freezing 647
2.1 Types of high-pressure freezing processes 648
2.1.1 High-pressure assisted freezing 649
2.1.1.1 Description of the process 649
2.1.1.2 Quality of pressure-assisted frozen foods 651
2.1.2 High-pressure shift freezing 652
2.1.2.1 Description of the process 652
2.1.2.2 Quality of high-pressure shift frozen foods 653
2.1.3 High-pressure induced freezing 656
2.2 Use of additives 656
2.3 Microbial and enzymatic inactivation 658
3 Modelling high-pressure freezing processes 658
3.1 Thermophysical properties under pressure 659
3.2 Temperature variation after an adiabatic pressure change 660
3.3 Convective phenomena 660
3.4 Modelling high-pressure assisted freezing processes 661
3.5 Modelling high-pressure shift freezing processes 661
3.6 Future perspectives: thermal control of high-pressure freezing processes 664
4 Conclusions 665
Nomenclature 666
References 666
25. Controlling the Freezing Process with Antifreeze Proteins 672
1 Introduction 672
2 Antifreeze proteins 674
2.1 Ice and freeze survival 674
2.2 The discovery of AFPs 677
2.3 AFP structures and evolution 681
2.4 Mechanisms of AFP activity 685
2.5 The use of AFPs in food preservation 688
3 Conclusions 690
References 691
Part 6 Minimal Processing 694
26. Minimal Fresh Processing of Vegetables, Fruits and Juices 696
1 Introduction 697
2 Factors and processing operations that affect quality of minimally fresh processed plant foods 700
2.1 Plant material 701
2.2 Processing line, distribution and storage conditions 703
2.2.1 Processing line 703
2.2.1.1 Whole product washing 704
2.2.1.2 Peeling and cutting 704
2.2.1.3 Washing and disinfection 706
2.2.1.4 Dewatering 708
2.2.2 Distribution and storage conditions 709
3 Emerging technologies for keeping microbial and sensory quality of minimally fresh processed fruits and vegetables 710
3.1 Disinfection 710
3.1.1 Hydrogen peroxide 711
3.1.2 Acidic electrolysed water 711
3.1.3 Chlorine dioxide 712
3.1.4 Organic acids 712
3.1.5 Ozone 713
3.1.6 Hot water treatments 714
3.1.7 UV-C radiation 714
3.2 Other emerging techniques 716
3.2.1 Biocontrol 716
3.2.2 Novel MAP 717
3.2.3 Genetic engineering technology 718
4 Emerging technologies of minimally fresh processed fruit juices 718
4.1 Pulsed electric fields 720
4.2 High hydrostatic pressure 720
5 Conclusions 721
References 722
27. Minimal Processing of Ready Meals 736
1 Introduction 736
2 Design of total system 737
2.1 Solid/liquid mixtures 738
2.2 Solid foods 739
2.3 Consumer packs 739
3 Cook-chill 740
4 Cook-freeze 741
5 Sous-vide 742
6 Novel and alternative processing options 744
6.1 Microwave heating 744
6.2 Ohmic heating 747
6.3 Hydrostatic processing 748
6.4 Surface decontamination techniques 748
6.5 Aseptic processing 749
6.6 Irradiation 749
7 Conclusions 750
References 750
28. Modified Atmosphere Packaging for Minimally Processed Foods 752
1 Introduction 752
2 Properties of packaged food 753
2.1 Optimal gas atmospheres 753
2.2 Gas solubility in foods 755
2.3 Tissue respiration 757
2.3.1 Respiration rate measurement 757
2.3.2 Respiration models 759
3 Properties of packaging materials 762
3.1 Film permeability 762
3.2 Package configuration 765
3.3 Gas scavenger and generator systems 766
4 Modified atmosphere packaging design 766
4.1 Barrier systems 766
4.2 Steady-state systems 767
5 Conclusions 769
Nomenclature 769
References 771
Index 776
A 776
B 776
C 777
D 777
E 777
F 778
G 779
H 779
I 780
J 780
L 780
M 780
N 782
O 782
P 783
R 785
S 785
T 786
U 786
V 787
W 787
Y 787