Water Activity: Influences on Food Quality (eBook)

Front Cover 1
Water Activity: Influences on Food Quality 4
Copyright Page 5
Table of Contents 6
Contributors 10
Preface 14
Acknowledgments 18
Section 1. Characterization of Moisture Sorption Isotherms 20
CHAPTER 1. WATER ACTIVITY AND ITS ESTIMATION IN FOOD SYSTEMS:THEORETICAL ASPECTS 20
I. INTRODUCTION 20
II. WATER VAPOR SORPTION AND THE NATURE OF INTERACTION BETWEEN WATER AND FOOD SOLIDS 27
III. FREE ENERGY AND DEFINITION OF ACTIVITY 33
IV. MIXTURES 38
V. SORPTION MODELS 53
VI. CONCLUDING REMARKS 60
.cknowledgments 62
APPENDIX 63
References 75
CHAPTER 2. DERIVATION OF FULL RANGE MOISTURE SORPTION ISOTHERMS 82
I. INTRODUCTION 82
II. SOME ADSORPTION EQUATIONS APPLIED TO FOODS 83
III. ISOTHERM SHAPES 91
IV. FINITE ADSORPTION AND LIMITS OF MULTILAYERED ADSORPTION 92
V. DENSITY OF ADSORBED MOISTURE AND THE CONSTANT c 95
VI. NONFREEZABLE OR BOUND WATER 96
VII. NATURE OF THE ADSORBED MOISTURE 98
VIII. SURFACE AREA OF ADSORBENTS 99
IX. SPECIAL ISOTHERM EQUATIONS 102
Acknowledgment 105
References 105
CHAPTER 3. RECENT DEVELOPMENTS IN TECHNIQUES FOR OBTAINING COMPLETE SORPTION ISOTHERMS 108
I. INTRODUCTION 108
II. APPARATUS AND METHODS 111
III. CONCLUSIONS 126
ACKNOWLEDGMENTS 127
REFERENCES 127
CHAPTER 4. WATER VAPOR SORPTION ISOTHERMS ON MACROMOLECULAR SUBSTRATES 130
I. INTRODUCTION 130
II. DETERMINATION OF ISOTHERMS 132
III. THEORETICAL ANALYSIS OF ISOTHERMS 134
IV. VARIATIONS OF SORPTION BEHAVIOR 152
V. CONCLUSION 158
References 160
CHAPTER 5. MOISTURE SORPTION HYSTERESIS 162
I. INTRODUCTION 162
II. THE THEORETICAL BASIS OF SORPTION HYSTERESIS 163
III. PRACTICAL ASPECTS OF MOISTURE SORPTION HYSTERESIS IN FOODS 183
IV. FUTURE RESEARCH 193
References 194
CHAPTER 6. EFFECT OF WATER ACTIVITY AND SORPTION HYSTERESIS ON RHEOLOGICAL BEHAVIOR OF WHEAT KERNELS 198
I. MATERIALS AND METHODS 199
II. EXPERIMENTAL PROCEDURE 200
III. RESULTS AND DISCUSSION 203
IV. CONCLUSION 214
Acknowledgments 216
References 216
CHAPTER 7. EVALUATION OF CRITICAL PARAMETERS FOR DEVELOPING MOISTURE SORPTION ISOTHERMS OF CEREAL GRAINS 218
I. CHARACTERISTICS OF CEREAL GRAINS 218
II. PUBLISHED SORPTION ISOTHERMS FOR CORN 222
III. COMMENTARY ON PREVIOUS STUDIES 225
IV. A DEFINITION FOR MOISTURE SORPTION ISOTHERMS 226
V. FACTORS INFLUENCING EQUILIBRIUM MOISTURE CONTENT 226
References 239
Section 2. Bound Water 242
CHAPTER 8. WATER BINDING ON STARCH: NMR STUDIES ON NATIVE AND GELATINIZED STARCH 242
I. INTRODUCTION 242
II. RELAXATION TIMES OF WATER IN STARCHES 244
III. ANISOTROPIC MOBILITY OF WATER 248
IV. SWELLING, RETROGRADATION, AND FREEZE-THAW BEHAVIOR 259
ACKNOWLEDGMENTS 263
REFERENCES 263
CHAPTER 9. PULSED NMR AND STATE OF WATER IN FOODS 266
I. INTRODUCTION 266
II. METHOD AND MATERIALS 267
III. RESULTS AND DISCUSSIONS 269
IV. CONCLUSIONS 283
REFERENCES 283
CHAPTER 10. DETERMINATION OF BINDING ENERGYFOR THE THREE FRACTIONS OF BOUND WATER 284
I. INTRODUCTION 284
II. BINDING ENERGY 285
References 297
CHAPTER 11. HYDRATION AROUND HYDROPHOBIC GROUPS 300
I. INTRODUCTION 300
II. AMOUNT OF HYDROPHOBIC HYDRATION 301
III. ADIABATIC COMPRESSIBILITY OF HYDROPHOBIC HYDRATION 304
IV. TEMPERATURE DEPENDENCE OF HYDROPHOBIC HYDRATION 305
V. CONCLUSION 309
Acknowledgments 311
References 311
Section 3. Solute Mobility in Aqueous Systems andWater - Membrane Interactions 314
CHAPTER 12. SOLUTE MOBILITY IN RELATION TO WATER CONTENT AND WATER ACTIVITY 314
ACKNOWLEDGMENTS 334
REFERENCES 334
CHAPTER 13. USE OF ELECTRON SPIN RESONANCE FOR THE STUDY OF SOLUTE MOBILITYIN RELATION TO MOISTURE CONTENT IN MODEL FOOD SYSTEMS 338
I. INTRODUCTION 338
II. THE SPIN PROBE ESR TECHNIQUE 339
III . METHODS 345
IV. RESULTS 348
V. DISCUSSION 357
VI. CONCLUSION 363
Acknowledgments 364
References 364
CHAPTER 14. A THERMODYNAMIC MODEL FOR TERPENE-WATER SOLUTIONS 366
I. INTRODUCTION 366
II. THERMODYNAMIC MODEL FOR SPARINGLY SOLUBLE COMPOUNDS IN WATER 367
III. DISCUSSION 386
IV. CONCLUSION 391
Acknowledgment 391
References 393
CHAPTER 15. HYDRATION OF BIOLOGICAL MEMBRANES 396
I. INTRODUCTION 396
II. HYDRATION OF BIOLOGICAL MEMBRANES 397
III. SPECTROSCOPIC STUDIES 406
IV. ROLE OF BOUND WATER IN BIOLOGICAL MEMBRANE STRUCTURE 419
ACKNOWLEDGMENTS 422
REFERENCES 423
CHAPTER 16. STRUCTURES OF WATER IN AQUEOUS SYSTEMS 426
I. INTRODUCTION 426
II. STRUCTURE OF LIQUID WATER 426
III. AQUEOUS SOLUTIONS 431
IV. THE "HYDROPHOBIC" BOND 431
V. HYDRATION OF ORGANIC MOLECULES 433
VI. ELECTROLYTE SOLUTIONS 435
VII. HYDRATION OF BIOPOLYMERS 440
VIII. MECHANISM OF DESALINATION MEMBRANES 448
IX. MECHANISM OF BOUND WATER 450
REFERENCES 452
Section 4. Influence of Water on Chemical Structure and Reactivity 454
CHAPTER 17. THEORETICAL STUDIES OF WATER IN CARBOHYDRATES AND PROTEINS 454
I. INTRODUCTION 454
II. SOME SPACE-FILLING PEPTIDE MODELS 455
III. WATER-PEPTIDE STUDIES WITH DREIDING STEREOMODELS 459
IV. "OPEN-CHAIN" PEPTIDES AND ADDITIONAL OBSERVATIONS ON WATER 460
V. PROTEIN MODELS WITH HEXAGONAL PAPERS 466
VI. WATER AND PROTEIN AGGREGATION 468
VII. MODEL STUDIES OF WATER-CARBOHYDRATE INTERACTIONS 474
VIII. A PROPOSED ROLE FOR GLYCEROL AND OTHER MONO- AND DISACCHARIDES IN SOME LIVING SYSTEMS 480
IX. CONCLUSIONS 483
ACKNOWLEDGMENTS 483
REFERENCES 484
CHAPTER 18. HYDRATION OF MILK PROTEINS 486
I. INTRODUCTION 486
II. WATER VAPOR SORPTION 487
III. SORPTION AND PROTEIN SWELLING AND CONFORMATION 494
IV. BOUND OR UNFREEZABLE WATER 499
V. DAIRY PROCESSING AND MILK PROTEIN HYDRATION 500
VI. CONCLUSION 505
References 506
CHAPTER 19. PROTEASE ACTION ON PROTEINS AT LOW WATER CONCENTRATION 508
I. INTRODUCTION 508
II. PEPTIDE SYNTHESIS WITH PROTEASES 510
III. PLASTEIN REACTION 512
IV. AMINOLYSIS VERSUS HYDROLYSIS 517
V. PROTEASE-CATALYZED AMINOLYSIS OF PROTEINS 520
VI. CONCLUSION 527
References 528
Section 5. Influence of Water Activity on Chemical Reactivity andStability of Foods 530
CHAPTER 20. AUTOXIDATION-INITIATEDREACTIONS IN FOODS 530
I. INTRODUCTION 530
II. WATER AND FOOD STRUCTURE 533
III. PEROXIDIZING LIPIDS 536
IV. PRESENT AND FUTURE STUDIES 543
REFERENCES 546
CHAPTER 21. INFLUENCE OF WATER ACTIVITY ON STABILITY OF VITAMINS IN DEHYDRATED FOODS 550
I. INTRODUCTION 550
II. FAT-SOLUBLE VITAMINS 551
III. B COMPLEX VITAMINS 557
IV. ASCORBIC ACID 571
References 584
CHAPTER 22. FORMATION AND DECOMPOSITION OF BROWNING INTERMEDIATES AND VISIBLE SUGAR-AMINE BROWNING REACTIONS 586
I. INTRODUCTION 586
II. FORMATION OF BROWNING INTERMEDIATES AS AN EARLY INDICATION OF MAILLARD REACTION IN PRODUCTS OF PLANT ORIGIN 591
III. FORMATION AND DECOMPOSITION OF BROWNING INTERMEDIATES AND VISIBLE BROWNING IN MODEL SYSTEMS 609
IV. CONCLUSIONS 618
REFERENCES 621
CHAPTER 23. THE NONENZYMATIC BROWNING REACTION AS AFFECTED BY WATER IN FOODS 624
I. INTRODUCTION 624
II. GENERAL EFFECTS OF WATER ON BROWNING 625
III. GENERAL SCHEME FOR NONENZYMATIC BROWNING REACTIONS 630
IV. EFFECTS OF WATER ON PROTEIN QUALITY LOSS 649
Acknowledgments 666
References 666
CHAPTER 24. ACCELERATION OF CHEMICAL REACTIONS DUE TO FREEZING 670
I. INTRODUCTION 670
II. REACTIONS IN A FROZEN SOLUTION 678
III. TT EXAMINATIONS OF CURED AND UNCURED PORK BELLIES 681
IV. T-TT EXAMINATION OF VIENNA SAUSAGES 686
V. APPLE AROMA 688
VI. ACCELERATION OF CHEMICAL REACTIONS DUE TO FREEZING 692
VII. CONCLUSIONS 695
References 696
Section 6. Influence of Water Activity on Food Quality and Stability 698
CHAPTER 25. THE FORMS AND ENERGY OF MOISTURE BINDING IN FOODS AS A BASIS FOR CHOOSING RATIONAL METHODS FOR PROCESSING AND STORAGE 698
INTRODUCTION 698
II. MOISTURE BINDING ENERGY 698
III. THERMODYNAMIC CHARACTERISTICS OF MOIST MATERIALS 708
IV. MASS EXCHANGE CHARACTERISTICS OF A MOIST MATERIAL 717
V. THE CHOICE OF RATIONAL METHODS OF FOOD PROCESSING 720
VI. INFLUENCE OF WATER ON PRODUCT PROPERTIES 722
VII. ELECTROMAGNETIC FIELD EFFECT ON MOIST MATERIALS 727
References 729
CHAPTER 26. WATER ACTIVITY AT SUBFREEZING TEMPERATURES 732
I. INTRODUCTION 732
II. DEFINITION OF WATER ACTIVITY AT SUBFREEZING TEMPERATURES 733
III. PLOTTING OF aw VALUES OBTAINED AT SUBFREEZING TEMPERATURES 738
IV. TEMPERATURE DEPENDENCE OF atT VALUES 744
V. MEANING OF aw VALUES AT SUBFREEZING TEMPERATURES 745
VI. SUMMARY 749
ACKNOWLEDGMENTS 750
REFERENCES 750
CHAPTER 27. TRADITIONAL TECHNIQUES IN JAPAN FOR FOOD PRESERVATION BY FREEZING, THAWING, AND DRYING 752
I. INTRODUCTION 752
II. KORI-TOFU 753
III . HARUSAME 755
IV. AGAR 756
V. KORI-MOCHI 757
VI. KORI-KONNYAKU 759
VII. SUMMARY 760
Acknowledgments 760
References 761
CHAPTER 28. STATE OF WATER IN SEA FOOD 762
I. INTRODUCTION 762
II. WATER CONTENT IN FISH AND SHELLFISH 763
III. STATE OF WATER IN FISH MUSCLE OF VARYING FRESHNESS 764
IV. STATE OF WATER IN KAMABOKO 773
ACKNOWLEDGMENTS 781
REFERENCES 781
CHAPTER 29. ROLE OF WATER IN WITHERING OF LEAFY VEGETABLES 784
I. FRESH VS. COMPRESSED DRY VEGETABLES 785
II. VISCOELASTIC PROPERTIES OF WITHERED LEAFY VEGETABLES 789
III. EVAPORATION OF WATER FROM HARVESTED LEAFY VEGETABLES 801
REFERENCES 808
CHAPTER 30. INFLUENCE OF WATER ACTIVITYON THE MANUFACTURE AND AGING OF CHEESE 810
I. INTRODUCTION 810
II. aw MEASUREMENT IN CHEESE 811
III. INFLUENCE OF WATER ACTIVITY ON STARTER CULTURES USED IN CHEESE MANUFACTURE 813
IV. INFLUENCE OF aw ON HYDROLYSIS OF CHEESE PROTEINS 818
V. RELATIONSHIPS BETWEEN aw AND CHEESE COMPOSITION 821
VI. WATER ACTIVITY AND CHEESE DEFECTS 825
ACKNOWLEDGMENTS 829
REFERENCES 829
Section 7. Influence of Water Activity on the Behavior ofMicroorganisms 832
CHAPTER 31. THERMAL PROPERTIES OF WATER IN RELATION TO MICROBIAL CELLS 832
I. INTRODUCTION 832
II. EXPERIMENTAL 833
III. THEORETICAL 836
IV. DISCUSSION 838
References 842
CHAPTER 32. SPECIFIC SOLUTE EFFECTS ON MICROBIAL WATER RELATIONS 844
I. INTRODUCTION 844
II. BACTERIA 848
III. YEASTS 855
IV. MOLDS 860
V. MECHANISMS 861
VI. CONCLUSIONS 870
REFERENCES 872
CHAPTER 33. MICROBIOLOGY OF MEAT AND MEAT PRODUCTS IN HIGH- AND INTERMEDIATE-MOISTURE RANGES 874
I. INTRODUCTION 874
II. HURDLE EFFECT AND FOOD PRESERVATION 875
III. aw AND MICROORGANISMS 879
IV. aw OF MEAT SURFACES 894
V. HIGH-MOISTURE MEATS 898
VI. FROZEN MEATS 907
VII. INTERMEDIATE MOISTURE MEATS 909
VIII. SHELF-STABLE PRODUCTS 918
References 927
Index 936