Engineering Properties of Foods

Front Cover......Page 1
Preface......Page 4
The Editors......Page 6
Contributors......Page 8
Table of Contents......Page 10
 I. Introduction......Page 24
  B. Density......Page 25
  C. Porosity......Page 27
  D. Surface Area......Page 28
  A. Density Measurement......Page 29
  B. Measurement Techniques of Porosity......Page 37
  C. Surface Area......Page 38
  A. Predictions of Density......Page 39
  B. Predictions of Porosity......Page 45
  C. Prediction of Surface Area......Page 48
 List of Symbols......Page 56
 Subscripts......Page 57
 References......Page 58
 I. Introduction......Page 64
 II. Rheological Classification of Fluid Foods......Page 65
  A. Rheological Models for Viscous Foods......Page 70
  B. Rheological Models for Viscoelastic Fluid Foods......Page 79
  A. Solution Viscosity......Page 82
  B. Physicochemical Approach......Page 83
  A. Fundamental Methods......Page 84
  B. Empirical Methods......Page 94
  C. Imitative Methods......Page 95
 V. Flow of Fluid Foods in Tubes......Page 104
  A. Isothermal Flow of Fluids in Tubes......Page 105
 List of Symbols......Page 112
 Greek Symbols......Page 113
 References......Page 114
 I. Introduction......Page 124
  A. Introduction......Page 125
  B. Some Simple Tests......Page 127
  C. Rheological Modeling......Page 131
  D. Creep......Page 132
  E. Relaxation......Page 134
  A. Introduction......Page 136
  B. Theoretical Considerations......Page 137
  C. Application of Resonance......Page 143
  D. Application of Direct Stress–Strain Tests......Page 146
  A. Failure in Solid Foods......Page 149
  B. Glass Transition of Solid Foods......Page 151
  A. Introduction......Page 155
  B. Texture Profile Analysis......Page 156
  C. Texture (Shear) Press......Page 158
  E. FMC Pea Tenderometer......Page 159
  G. Other Empirical Methods......Page 160
 VI. Conclusions......Page 161
 References......Page 162
  A. The Importance of Thermal Properties for the Quality and Safety of Foods......Page 172
  B. Modeling and Optimization of Processes......Page 173
  C. Computerized and On-Line Databases......Page 174
 III. Density......Page 175
 IV. Specific Heat Capacity......Page 177
  B. Specific and Latent Heat of Fats......Page 179
  A. Predictive Equations......Page 180
 VI. Measurement Methods for Thermal Conductivity......Page 183
  A. The Basis of Operation of the Needle Probe......Page 184
  A. Compressibility and Thermal Expansion......Page 188
  B. Glass Transitions......Page 189
 Symbols, Names, and Dimensions......Page 190
 References......Page 191
 I. Introduction......Page 198
  A. Initial Freezing Point and Unfrozen Water......Page 199
  D. Enthalpy......Page 200
  F. Thermal Diffusivity......Page 201
 III. General Observations on the Reliability of Experimental Data......Page 204
  A. Prediction of Unfrozen Water During Freezing of Foods......Page 207
  B. Limitations of Predictive Models......Page 222
 Greek Symbols......Page 223
 References......Page 224
 I. Introduction......Page 232
  B. Interaction between Infrared Radiation and Food Materials......Page 233
  D. Emission and Emissivity......Page 235
  E. Reflection, Absorption, and Transmission......Page 237
  F. Absorptivity and Emissivity......Page 241
  G. Attenuation or Extinction......Page 242
 III. Use of the Radiative Properties in Modeling of Heat Transfer......Page 243
 IV. Measurement of Radiative Properties of Foods......Page 244
  A. Radiative Property Data for Water, Ice, and Water Vapor......Page 247
  C. Spectral Variation of Radiative Property Data: Potato Tissue as an Example......Page 248
  D. Moisture Dependence of Radiative Property Data......Page 250
  E. Temperature Dependence of Radiative Property Data......Page 251
  F. Dependence of Radiative Property Data on Food Structure......Page 253
  G. How Processing Can Change Food Radiative Properties......Page 254
  H. Summary: Use of Radiative Property Data in Modeling......Page 255
 References......Page 258
 I. Introduction......Page 262
 II. Thermodynamics of Food–Water Systems......Page 263
  A. Chemical Potential and Phase Equilibria......Page 265
  B. Fugacity and Activity......Page 267
  C. Water Activity in Foods......Page 269
  D. Measurement of Water Activity......Page 275
  E. Adjustment of Water Activity......Page 279
  F. Moisture Sorption Isotherms......Page 284
 III. Sorption Energetics......Page 295
  A. Differential Quantities......Page 296
  B. Integral Quantities......Page 299
  C. Hysteresis and Irreversibility......Page 304
  D. Kinetic Aspects......Page 310
 IV. Dehydration Principles and Processes......Page 311
  A. Drying Behavior......Page 313
  B. Constant-Rate Period......Page 316
  C. Falling-Rate Period......Page 318
  D. Equilibrium Moisture Content......Page 324
  E. Energy Requirements......Page 327
 V. Conclusion......Page 330
 List of Symbols......Page 331
 Greek Symbols......Page 332
 References......Page 333
 I. Introduction......Page 350
  A. Vapor–Liquid Equilibria......Page 352
  B. Gas–Liquid Equilibria......Page 356
  C. Liquid–Liquid and Liquid–Solid Equilibria......Page 358
  D. Gas–Solid and Vapor–Solid Equilibria......Page 359
 III. Diffusion......Page 361
  A. Diffusion in Gases......Page 362
  B. Diffusion in Liquids......Page 363
  C. Diffusion in Solids......Page 364
  D. Estimation of Diffusivity in Solids......Page 368
  A. Mass Transfer Coefficients......Page 372
  B. Penetration Theory......Page 374
  C. Analogies of Heat and Mass Transfer......Page 375
  D. Effect of Surfactants......Page 376
  A. Moisture Transport......Page 377
  B. Diffusion of Solutes......Page 383
  C. Diffusion of Aroma Compounds......Page 385
  A. Extraction......Page 387
  B. Distillation and Gas Absorption......Page 389
  C. Crystallization......Page 391
  D. Food Packaging......Page 393
 List of Symbols......Page 395
 References......Page 396
 I. Introduction......Page 404
  A. Case I: Preferential Sorption of Water at the Membrane–Solution Interface......Page 405
  B. Case II: Surface Force–Pore Flow Model; Generation of Interfacial Surface Force Parameters and Their Application......Page 412
 III. Problems in Membrane Separation and Concentration of Liquid Foods......Page 426
  A. Application of Water Preferential Sorption Model......Page 429
  B. Application of Transport Equations to Real Fruit Juice Concentration......Page 444
  C. Application of Transport Equations for the Concentration of Green Tea Juice......Page 449
  D. Some Illustrative Examples of the Surface Force–Pore Flow Model......Page 454
  E. Some Data on the Ultrafiltration of Proteins......Page 460
  F. Application of Pervaporation in the Recovery and Concentration of Food Flavors......Page 468
  A. Dairy Product Industry......Page 470
  B. Beverage Industry......Page 472
  C. Edible Oil Industry......Page 473
 V. Conclusion......Page 475
 List of Symbols......Page 476
 Greek Symbols......Page 477
 References......Page 478
 I. Introduction......Page 484
  A. Theory of Electrolytic Conductivity......Page 485
  B. Relations between Electrical Conductivity and Other Transport Properties......Page 488
  C. Effect of Temperature......Page 489
  D. Effect of Electric Field Strength......Page 490
  E. Effect of Ingredients......Page 491
  A. Effect of Microstructure......Page 497
  B. Effects of Temperature and Electric Field Strength......Page 498
  C. Effect of Frequency......Page 505
  D. Ingredient Effects......Page 510
  A. Models for Effective Electrical Conductivity......Page 511
  B. Effects of Solids in Tube Flow......Page 513
 VI. Methods of Measurement of Electrical Conductivity......Page 515
 Greek Letters and Other Symbols......Page 519
 References......Page 520
 I. Introduction......Page 524
 II. Basic Principles......Page 525
 III. Measurement Principles......Page 532
  B. Short-Circuited Line Technique......Page 533
  C. Open-Ended Probe Technique......Page 534
  E. Free-Space Transmission Technique......Page 535
  G. Six-Port Reflectometer Using an Open-Ended Coaxial Probe......Page 536
  J. Cavity Perturbation Technique......Page 537
  K. Summary of Dielectric Property Measurement Techniques......Page 540
  A. Frequency Dependence......Page 541
  A. Frequency Dependence in Food Materials......Page 544
  B. Temperature Dependence in Water, Salt Solutions, and Foods......Page 545
  A. Moisture Dependence......Page 554
  B. Dielectric Properties of Carbohydrates......Page 556
  C. Dielectric Properties of Proteins......Page 561
  D. Dielectric Properties of Fat......Page 564
  E. Dielectric Properties of Meats......Page 565
  F. Dielectric Properties of Fish and Seafood......Page 566
  G. Dielectric Properties of Fruits and Vegetables......Page 568
  H. Dielectric Properties of Dairy Products......Page 570
 VI. Dielectric Properties of Insect Pests......Page 573
  A. Baking......Page 574
  E. Storage......Page 577
 IX. Assessment of Food Quality by Using Dielectric Properties......Page 578
 References......Page 580
 I. Introduction......Page 590
  A. Speed of Sound, Density, and Elastic Moduli......Page 592
  B. Amplitude and Attenuation......Page 594
  C. Impedance, Reflection, and Refraction......Page 596
  D. Doppler Shift Frequency and Velocity......Page 597
 III. Ultrasonic Measurement Techniques......Page 598
  A. Ultrasonic Methods......Page 599
  B. Transducer Selection......Page 603
  A. Composition......Page 605
  B. Phase Transitions......Page 617
  C. Texture......Page 620
  D. Viscosity......Page 622
 V. Conclusion......Page 626
 Greek Symbols......Page 627
 References......Page 628
 I. Introduction......Page 634
 II. Fundamental Considerations......Page 637
  A. Primary Kinetic Models......Page 638
  B. Secondary Kinetic Models......Page 642
 III. Measurement Techniques......Page 644
  A. Microbial Inactivation......Page 646
  B. Enzyme Inactivation......Page 648
  C. Texture Degradation......Page 649
  D. Color Degradation......Page 650
  E. Flavor Degradation......Page 652
  F. Nutrient Degradation......Page 653
 References......Page 656
 I. Introduction......Page 668
  A. Respiration and Fermentation......Page 669
  B. Measurement Techniques......Page 678
 III. Applications......Page 686
 List of Symbols......Page 694
 References......Page 695
 I. Introduction......Page 702
  A. Definitions......Page 703
  B. The Gibbs Adsorption Equation......Page 705
  C. The Contact Angle......Page 707
  D. Effects of Adsorbed Layer Composition and Structure on Interfacial Energy......Page 713
  A. Evaluation of the Contact Angle......Page 716
  B. Evaluation of Liquid Surface Tension......Page 717
  C. Evaluation of γ[sub(L)][sup(d)] and γ[sub(S)][sup(d)]......Page 719
 IV. Surface Property Data......Page 720
 References......Page 722
 I. Introduction......Page 726
 II. Physiological Basis of Color......Page 727
  A. Spectrophotometry......Page 728
  B. Tristimulus Colorimetry......Page 734
  C. Specialized Colorimeters......Page 735
 IV. Presentation of Samples......Page 737
 V. Research and Quality Control Approaches......Page 740
 VI. Color Tolerances......Page 743
 VII. Development of Instruments......Page 746
 VIII. Conclusion......Page 749
 References......Page 750
Index......Page 756