상세정보

The object ofthis text is to examine, and elaborate on the meaning of the established premise that 'taste is a chemical sense.' In particular, the major effort is directed toward the degree to which chemical principles apply to phenomena associated with the inductive (recognition) phase of taste. A second objective is to describe the structure and properties of compounds with varying taste that allow decisions to be made with respect to the probable nature of the recognition chemistry for the different tastes, and the probable nature of the receptor(s) for those tastes. A final objective is to include appropriate interdisciplinary observations that have application to solving problems related to the chemical nature of taste. Taste is the most easily accessible chemical structure-biological activity relationship, and taste chemistry studies, i.e. the chemistry of sweetness, saltiness, sourness, and bitterness, have application to general biology, physiology, and pharmacology. Because it involves sensory perception, taste is also of interest to psychologists, and has application to the food and agricultural industries. The largest portion of the text is directed toward sweetness as, due to economic and other factors, the majority of the scientific studies are concerned with sweetness. The text begins with a prologue to describe the problems associated with the study of taste chemistry. Then, there is an introductory chapter to serve as an overview of the general interdisciplinary knowledge of the subject. It is followed by a chapter on the fundamental chemical principles that apply to taste induction chemistry.

The object ofthis text is to examine, and elaborate on the meaning of the established premise that 'taste is a chemical sense.' In particular, the major effort is directed toward the degree to which chemical principles apply to phenomena associated with the inductive (recognition) phase of taste. A second objective is to describe the structure and properties of compounds with varying taste that allow decisions to be made with respect to the probable nature of the recognition chemistry for the different tastes, and the probable nature of the receptor(s) for those tastes. A final objective is to include appropriate interdisciplinary observations that have application to solving problems related to the chemical nature of taste. Taste is the most easily accessible chemical structure-biological activity relationship, and taste chemistry studies, i.e. the chemistry of sweetness, saltiness, sourness, and bitterness, have application to general biology, physiology, and pharmacology. Because it involves sensory perception, taste is also of interest to psychologists, and has application to the food and agricultural industries. The largest portion of the text is directed toward sweetness as, due to economic and other factors, the majority of the scientific studies are concerned with sweetness. The text begins with a prologue to describe the problems associated with the study of taste chemistry. Then, there is an introductory chapter to serve as an overview of the general interdisciplinary knowledge of the subject. It is followed by a chapter on the fundamental chemical principles that apply to taste induction chemistry.

정보제공 :

CONTENTS
Preface = vii
Prologue = 1
1. CHEMICAL NATURE, PSYCHOLOGY, AND PHYSIOLOGY OF TASTE = 5
  1.1 GENERAL NATURE OF TASTE = 5
    1.1.1 The basic tastes = 5
    1.1.2 Definition of sweetness, saltiness, sourness, and bitterness = 8
    1.1.3 Taste Profiles and taste spectra = 8
      1.1.3.1 Taste profiles = 8
      1.1.3.2 Taste s[ectra = 9
      1.1.3.3 Taste spectra specification for basic tastes = 10
    1.1.4 Morphological receptors for the basic tastes = 12
      1.1.4.1 Distribution of tastes = 12
      1.1.4.2 Distribution of receptors = 12
      1.1.4.3 Response of taste buds to different stimuli = 13
    1.1.5 Taste ' blindness ' = 16
    1.1.6 Taste blocking and modification = 17
      1.1.6.1 Taste blocking = 17
      1.1.6.2 Taste modification = 19
  1.2 TASTE MEASUREMENT = 20
    1.2.1 Threshold determinations = 21
    1.2.2 Comparison tests = 23
    1.2.3 Scaling Procedures = 23
  1.3 PSYCHOPHYSICAL PRINCIPLES = 23
    1.3.1 Psychophysical laws = 24
    1.3.2 Adaptation and cross - adaptation = 29
      1.3.2.1 Cross - adaptation to saltiness = 31
      1.3.2.2 Cross - adaptation to sourness = 32
      1.3.2.3 Cross - adaptation to bitteness = 32
      1.3.2.4 Cross - adaptation to sweetness = 32
      1.3.2.5 Effect of addaptation on other taste qualities = 33
      1.3.2.6 Mechaiosm of adaptation = 33
    1.3.3. Taste of mixtures = 34
  1.4 TRANSDUCTION
  1.5 OVERVIEW OF THE TASTE OF CHEMICALS = 38
    1.5.1 Chemicals that taste sweet, salty, sour, and bitter = 39
    1.5.2 Taste transformations = 41
    1.5.3 Common chemical sense taste attributes = 43
  1.6 CHEMICAL INTERRELATIONS AMONG THE FOUR TASTES = 45
2. TASTE CHEMISTRY PRINCIPLES = 47
  2.1 CHEMICAL EQUIVALENTS = 47
  2.2 WATER SOLUBILITY AND REACTIONS IN WATER = 48
  2.3 pH, pK, AND TOTAL ACIDITY = 49
    2.3.1 Definition of an acid and base = 49
    2.3.2 pH = 50
    2.3.3 pK = 51
    2.3.4 Total acidity = 52
  2.4 MASS ACTION AND CHEMICAL EQUILIBRIA = 52
    2.4.1 Mass action = 52
    2.4.2 Chemical equilibria = 54
      2.4.2.1 Chemical activity = 55
      2.4.2.2 Taste chemical equilibria = 56
  2.5 cHEMICAL kINETICS
    2.5.1 Zero - order reactions = 57
    2.5.2 First - order reactions = 57
    2.5.3 Calculation of first - order velocity constants = 59
    2.5.4 Calculation of First - order equilibrium constants = 60
  2.6 THERMODYNAMICS = 61
    2.6.1 Enthalpy = 61
    2.6.2 entropy = 62
    2.6.3 Significance of free Energy in taste = 63
  2.7 NATURE OF CHEMICAL BONDS AND CHEMICAL REACTIONS = 64
    2.7.1 The covalent bond = 64
    2.7.2 The ionic(electrostatic)bond = 65
    2.7.3 The hydrogen bond = 65
      2.7.3.1 Nature of the hydrogen bond = 65
      2.7.3.2 Strength of the hydrogen bond = 67
      2.7.3.3 Inter - and intramolecular hydrogen bonds = 68
      2.7.3.4 Cooperative hydrogen bonding = 68
    2.7.4 The hydrophobic bond = 69
    2.7.5 van der Waals interactions = 70
    2.7.6 Charge transfer reactions = 72
    2.7.7 Displacement reactions = 72
  2.8 INDUCTIVE AND RESONANCE EFFECTS = 73
  2.9 ISOSTERIC GROUPS = 76
  2.10 TASTE STRUCTURE - ACTIVITY THEORY = 77
    2.10.1 Occupancy theory = 77
    2.10.2 Hit - run theory = 79
    2.10.3 Rate theory = 79
    2.10.4 Inhibition = 79
      2.10.4.1 Competitive inhibition = 80
      2.10.4.2 Noncompetitive inhibition = 81
      2.10.4.3 Uncompetitive inhibition = 81
  2.11 SYMMETRY AND CHIRALITY = 82
    2.11.1 Principles of symmetry = 84
      2.11.1.1 Rotation = 85
      2.11.1.2 Reflection = 87
      2.11.1.3 Rotation - reflection = 87
      2.11.1.4 Rotation - inversion axes = 88
      2.11.1.5 Two - dimensional symmetry point groups = 89
      2.11.1.6 Three - dimensional symmetry point groups = 91
    2.11.2 Dissymmetry and asymmetry = 93
    2.11.3 Chirality = 93
      2.11.3.1 Demonstration of chirality = 94
      2.11.3.2 Classification of symmetry and chirality = 95
      2.11.3.3 The asymmetric carbon atom = 99
      2.11.3.4 Sources of chirality in compounds = 99
        Helical arrays of atoms = 99
        Differential labeling = 100
        Conformational skewing = 100
      2.11.3.5 Chiral operations and specification = 100
      2.11.3.6 Prochirality = 102
    2.11.4 Bilateral symmetry = 106
  2.12 RECOGNITION CHEMISTRY = 108
3. WATER AND INORGANIC COMPOUNDS = 110
  3.1 WATER = 110
    3.1.1 Composition and elemental structure of water = 111
    3.1.2 Hydrogen - bonded structure of water = 112
      3.1.2.1 Continuum models = 112
      3.1.2.2 Mixed and dynamic models = 116
    3.1.3 Hydrogen bonding of water with other functional groups = 119
    3.1.4 Taste of water = 120
  3.2 ALKALI METAL AND HALOGEN SALTS = 120
    3.2.1 Reactivity of the Group I metal salts = 123
    3.2.2 Halogens = 125
    3.2.3 Ionic structure of sodium chloride = 126
    3.2.4 Solution properties of Group I salts = 127
  3.3 LEAD AND BERYLLIUM SALTS = 129
    3.3.1 Salts of beryllium = 130
    3.3.2 Lead acetate(sugar of lead) = 132
  3.4 TASTE OF SALTS = 132
    3.4.1 Sodium chloride = 133
    3.4.2 Potassium coloride = 135
    3.4.3 Lithium chloride = 135
    3.4.4 Lithium sulface = 136
    3.4.5 Potassium sulfate = 137
    3.4.6 Relative sweetness of salts = 137
  3.5 INORGANIC ACIDS = 138
    3.5.1 Hydrochloric acid = 138
    3.5.2 Sulfuric acid = 139
    3.5.3 Phosphoric acid = 139
  3.6 SOURNESS OF INORGANIC ACIDS = 139
4. POLYHYDROXY ALCOHOLS, CYCLITOLS, AND CARBONYL COMPOUNDS = 141
  4.1 ACYCLIC POLYHYDROXY ALCOHOLS = 142
    4.1.1 Ethylene glycol = 142
    4.1.2 Glycerol = 143
    4.1.3 Erythritol = 143
    4.1.4 Arabitol = 144
    4.1.5 Xylitol = 145
    4.1.6 Galactitol = 145
    4.1.7 Sorbitol = 145
    4.1.8 Mannitol = 145
    4.1.9 Maltitol = 145
    4.1.10 Lactitol = 146
    4.1.11 Palatinit = 146
  4.2 CYCLIC SUGAR ALCOHOLS = 146
  4.3 CYCLITOLS = 146
  4.4 hYDROXY CARBONYL COMPOUNDS = 149
    4.4.1 Glycolaldehyde = 150
    4.4.2 Glyceraldehyde = 150
    4.4.3 Dihydroxyacetone = 152
    4.4.4 Importance to structure - activity relationships = 152
5. STRUCTURE, REACTIONS AND PROPERTIES OF SUGARS = 153
  5.1 SIMPLE SUGARS(MONOSACCHARIDES) = 153
    5.1.1 Acyclic structure of the sugars = 154
      5.1.1.1 Fischer projection structures = 154
      5.1.1.2 Specification of the chiral family(D - or L -) = 157
      5.1.1.3 Specification of sugar multiple configuration = 158
    5.1.2 Ring forms of the sugars = 160
      5.1.2.1 Haworth structures = 161
      5.1.2.2 Conformational structures = 164
    5.1.3 Naturally occurring monosaccharides = 168
      5.1.3.1 Arabinose = 168
      5.1.3.2 Ribose = 169
      5.1.3.3 Xylose(wood sugar) = 170
      5.1.3.4 Glucose = 170
      5.1.3.5 Galactose = 170
      5.1.3.6 Manose = 171
      5.1.3.7 Fructose = 171
  5.2 OLIGOSACCHARIDES = 171
    5.2.1 Formation of oligosaccharides = 172
    5.2.2 Oligosaccharide nomenclature = 172
    5.2.3 Naturally occurring oligosaccharides = 172
      5.2.3.1 Sucrose = 174
      5.2.3.2 Lactose = 174
      5.2.3.3 Maltose = 176
      5.2.3.4 Raffinose = 176
      5.2.3.5 Stachyose = 176
      5.2.3.6 α , α - Trehalose = 176
  5.3 REACTIONS OF SUGARS = 177
    5.3.1 Oxidation, reduction = 177
    5.3.2 Reactions of hydroxyl groups = 178
    5.3.3 Mutarotation = 178
    5.3.4 Sucrose inversion = 180
    5.3.5 Caramelization = 183
    5.3.6 Anhydride formation = 184
  5.4 PROPERTIES OF SUGARS = 185
    5.4.1 Water solubility = 185
    5.4.2 Hygroscopicity = 186
    5.4.3 Water activity = 187
    5.4.4 Partition coefficients = 187
6. SWEETNESS AND OTHER TASTE ATTRIBUTES OF THE SUGARS = 189
  6.1 INTRINSIC SWEETNESS OF SUGARS = 189
    6.1.1 Effect of concentration = 189
    6.1.2 Effect of temperature = 191
  6.2 RELATIVE SWEETNESS OF SUGARS = 191
    6.2.1 Glucose = 195
    6.2.2 fructose = 195
    6.2.3 Fructose syrups = 196
    6.2.4 Galactose = 196
    6.2.5 Mannose = 196
    6.2.6 Maltose and maltose / glucose syrups = 196
    6.2.7 Lactose = 197
  6.3 EFFECT OF CONCENTRATION ON RELATIVE SWEETNESS = 198
  6.4 REACTIONS AFFECTING RELATIVE SWEETNESS = 198
    6.4.1 Conventional mutarotation = 198
    6.4.2 Thermal mutarotation = 199
    6.4.3 Inversion of sucrose = 199
    6.4.4 Reversion = 201
    6.4.5 Effect of substitution on sweetness = 202
      6.4.5.1 Methylation = 202
      6.4.5.2 Deoxy - sugars = 205
      6.4.5.3 Chloro - and thio - sugars = 205
      6.4.5.4 Replacement of the ring oxygen atom = 206
  6.5 RELATION BETWEEN STRUCTURE AND TASTE IN THE SUGAR SERIES = 207
  6.6 SUPPLEMENTAL FOOD ATTRIBUTES OF SUGARS = 208
    6.6.1 Stoichiometric association of sugars with water = 208
    6.6.2 Osmotic pressure = 212
    6.6.3 Viscosity = 212
    6.6.4 Boiling point elevation, freezing point depression = 213
7. AMINO ACIDS, PEPTIDES AND PROTEINS = 213
  7.1 STRUCTURE, CLASSIFICATION, AND PROPERTIES OF AMINO ACIDS = 213
    7.1.1 Structure = 213
    7.1.2 Classification = 215
    7.1.3 Reactions and properties of amino acids = 216
      7.1.3.1 Zwitterionic forms = 217
      7.1.3.2 Hydration of zwitterions = 217
      7.1.3.3 Schiff base formation = 218
      7.1.3.4 Side chain free energy(hydrophobicity) = 219
  7.2 PEPTIDES AND PROTEINS = 220
    7.2.1 The peptide bond = 220
    7.2.2 Primary, secondary, and tertiary protein structure = 222
      7.2.2.1 The α - helix = 222
      7.2.2.2 Pleated sheet conformation = 223
      7.2.2.3 Folded and random coil forms = 223
    7.2.3 Denaturation = 225
  7.3 TASTE OF AMINO ACIDS = 226
  7.4 TASTE OF PEPTIDES = 233
    7.4.1 Peptides with sweet taste = 233
      7.4.1.1 L - Aspartic acid peptides = 234
      7.4.1.2 Retro - inverso peptides and amides = 238
      7.4.1.3 Extraordinarily sweet organic substances = 243
    7.4.2 Peptides with bitter taste = 246
    7.4.3 Peptides with sour taste = 246
    7.4.4 Peptides with salty taste = 247
  7.5 TASTE OF PROTEINS = 247
    7.5.1 Miraculin = 247
    7.5.2 Monellin = 248
    7.5.3 Thaumatins = 250
8. ORGANIC COMPOUNDS = 253
  8.1 SWEET ORGANIC COMPOUNDS = 253
    8.1.1 Nitroaniline compounds = 253
    8.1.2 Saccharine = 255
    8.1.3 Sulfamates = 260
    8.1.4 Oximes = 262
    8.1.5 Diphenyl substances = 267
      8.1.5.1 Isocoumarins = 268
      8.1.5.2 Flavone derivatives = 269
      8.1.5.3 Dihydrochalcons = 271
      8.1.5.4 Isovanillyl compounds = 275
    8.1.6 Sesquiterpenes = 277
    8.1.7 Ureas = 277
    8.1.8 Sulfones = 281
  8.2 BITTER ORGANIC SUBSTANCES = 282
    8.2.1 Alkaloids = 283
      8.2.1.1 Strychnine = 283
      8.2.1.2 Brucine = 283
      8.2.1.3 Piperine = 284
      8.2.1.4 Solanine = 284
      8.2.1.5 Ouinine = 284
      8.2.1.6 Caffeine = 284
    8.2.2 Amides and thioureas(thioamides) = 285
    8.2.3 Diterpenes = 286
    8.2.4 Extraordinarily bitter organic substances = 287
  8.3 SOUR AND SALTY ORGANIC SUBSTANCES = 289
    8.3.1 Sourness of organic acids = 291
9. THE COMMON SAPOROUS UNITS FOR TASTE = 292
  9.1 THE COMMON ACIDOPHORE = 292
  9.2 THE COMMON hALOPHORE = 293
  9.3 THE SEARCH FOR THE COMMON GLYCOPHORE = 295
    9.3.1 The glucogene = 295
    9.3.2 The auxogluc and glucophore = 297
    9.3.3 Vibratory and resonationg hydrogen atoms = 297
    9.3.4 The taste couple = 297
    9.3.5 Derivation of the sugar glycophore as AH, B = 298
    9.3.6 Reinicks's oxygen tetrahedra in para position = 298
    9.3.7 Rationalization of the varying sweetness of the sugars = 300
      9.3.7.1 Fischer configurational structures = 301
      9.3.7.2 Hawoth ring structures = 302
      9.3.7.3 Conformational structures = 302
      9.3.7.4 Intramolecular hydrogen bonding in model compounds = 304
      9.3.7.5 Hydrogen bonding in sugars = 307
    9.3.8 The glycol group as an AH, B hydrogen bonding unit = 311
      9.3.8.1 Cyelitols and aldohexoses = 312
      9.3.8.2 Ketohexoses = 316
      9.3.8.3 Sucrose = 320
    9.3.9 AH, B in other sweet compounds = 323
      9.3.9.1 Metal salts = 323
      9.3.9.2 Halogenated hydrocarbons = 325
      9.3.9.3 Polyhydroxy alcohols = 325
      9.3.9.4 Amino acids, amides, peptides, and proteins = 326
    9.3.10 The tripartite glyeophore for sweetness = 330
      9.3.10.1 Chemical nature of the third glycophore component ( γ ) = 330
      9.3.10.2 AH, B, γ in the sugars = 331
      9.3.10.3 Optimum position of γ = 332
    9.3.11 General occurrence of AH, B, in sweet organic compounds = 333
      9.3.11.1 Nitroaniline compounds = 333
      9.3.11.2 Oximes = 335
      9.3.11.3 Saccharine, sulfamates = 338
      9.3.11.4 Halogenated organic compounds = 342
      9.3.11.5 Diphenyl substances = 344
      9.3.11.6 Sesquiterpenes = 347
      9.3.11.7 Ureas = 348
      9.3.11.8 Sulfones = 351
      9.3.11.9 Amino acids and peptides = 351
    9.3.12 General geometry of AH, B, γ = 354
      9.3.12.1 AH, b, γ coordinates = 355
      9.3.12.2 Sweet | bitter | tasteless AH, B, γ coordinates = 356
      9.3.13 Alternatives to AH, B, γ as a common glycophore = 358
      9.3.13.1 An electrophilic nucleophilic unit as the glycophore = 358
      9.3.13.2 General glycophore functions and falilies = 363
      9.3.13.3 AH, B, γ glycosteric groups 371
      9.3.13.4 Electrostatic potentials = 371
  9.4 THE PICROPHORE = 372
10 THE INITIAL CHEMISTRY OF TASTE = 377
  10.1 INITIAL CHEMISTRY OF SOURNESS = 378
  10.2 INITIAL CHEMISTRY OF SALTINESS = 380
  10.3 INITIAL CHEMISTRY OF SWEETNESS = 382
    10.3.1 The concerted bipartite AH, B interaction = 383
    10.3.2 The dynamic(equilibrium) AH, B model = 386
    10.3.3 Multiple AH, B equivalency = 388
    10.3.4 Function of γ = 389
      10.3.4.1 Activation of glycophore and receptor AH, B = 390
      10.3.4.2 Groups with strong inductive effect on AH, B = 394
    10.3.5 Alternatives to the conceryed AH, B chemical interaction = 395
      10.3.5.1 Ionic versus hydrogen bonding mechanisms = 395
      10.3.5.2 Conceryed AH, B as an electrophilic / mucleophilic system = 396
      10.3.5.3 Nonchemical mechanisms for sweetness = 402
  10.4 SPECIAL QUALITATIVE ASPECTS OF THE INITIAL CHEMISTRY OF SWEETNESS = 404
    10.4.1 High - potency sweetness variation with concentration = 404
    10.4.2 The orderly queue = 407
    10.4.3 Solution properties of substances and initial taste chemistry = 408
      10.4.3.1 Molar volume and intrinsic viscosity of substances = 409
      10.4.3.2 Role of water in molecular rccognition = 410
  10.5 INITIAL CHEMISTRY OF BITTERNESS = 410
  10.6 STRUCTURE - ACTIVITY RELATIONSHIPS = 412
    10.6.1 Hansch π and Hammett constants = 414
    10.6.2 The McFaland probability model = 416
    10.6.3 Interaction energy = 419
      10.6.3.1 Electrostatic energy = 420
      10.6.3.2 Polarization energy = 420
      10.6.3.3 Dispersion energy = 420
      10.6.3.4 Repulsion energy = 421
      10.6.3.5 Relation between intersity and binding energy = 421
      10.6.3.6 Correlation of binding energy parameters with taste intensity = 423
    10.6.4 Molecular connectivity = 424
      10.6.4.1 Application of the connectivity terms to alkanes = 430
      10.6.4.2 Significance of connectivity indices = 431
      10.6.4.3 Application of connectivity to nitroaniline and oxime taste = 432
      10.6.4.4 Application to the varying sweetness of the sugars = 433
      10.6.4.5 Sulfamate side chail / connectivity relations = 439
  10.7 KINETIC THEORY = 440
    10.7.1 The beidler equation = 440
    10.7.2 Taste association constants = 440
    10.7.3 Taste dissociation constants = 443
  10.8 MECHANISM(S)OF TASTE INHIBITION = 445
  10.9 RECOGNITION CHEMISTRY VERSUS BINDING AFFINITY = 448
11. SYMMETRY, CHIRALITY AND TOPOLOGY IN TASTE = 449
  11.1 SYMMETRY IN TASTE = 450
    11.1.1 The sour and alkaline tastes = 451
    11.1.2 Saltiness / bitterness = 452
    11.1.3 Sweetness / bitterness = 453
    11.1.4 Symmetry classification of tastes = 456
  11.2 CHIRALITY IN TASTE = 457
    11.2.1 The bipartite glycophore and receptor = 458
      11.2.1.1 D = and L - amino acids = 458
      11.2.1.2 D - amd L - Sugars = 459
    11.2.2 The Tripartite glycophore and receptor = 461
      11.2.2.1 Tripartite glycophore isomers = 462
      11.2.2.2 Specification of the chiral nature of the glycophore and recrptor = 465
      11.2.2.3 Application of chiral glycophore calculations to planar compounds = 466
      11.2.2.4 Application of glycophore calculations to nonplanar compounds = 468
        fructose = 468
        Asparagine = 470
      11.2.2.5 Application to the sweetness / bitterness of amino acids and peptides = 474
      11.2.2.6 Chirality in the α function = 475
  11.3 CHIRALITY PLUS TOPOLOGY IN TASTE = 478
    11.3.1 Mirror image models = 478
    11.3.2 Topological receptor models = 480
  11.4 TOPOLOGY IN TASTE = 483
    11.4.1 The Temussi model for bitterness / sweetness = 484
    11.4.2 The Culberson - Walters model for the sweetness receptor = 488
    11.4.3 The Tinti / Nofre topological model for sweetness = 489
  11.5 SYMMETRY, CHIRALITY AND TOPOLOGY IN RETROSPECT = 491
    11.5.1 Role of bilateral symmetry = 491
    11.5.2 Role of prochirality and prosymmetry = 491
    11.5.3 Role of topology = 492
12. THE TASTE RECEPTOR(S) = 493
  12.1 THE TASTE CELL MEMBRANE = 493
  12.2 PROTEIN NATURE OF THE TASTE RECEPTOR(S) = 495
    12.2.1 Isolation and enzyme studies = 495
    12.2.2 Immunological studies = 495
    12.2.3 Nagure of the protein - tastant interaction = 497
    12.2.4 Hydration of a dynamic menbrane protein receptor model = 498
    12.2.5 protein receptor medels for taste = 499
  12.3 MEANING OF THE TERM ' DIFFERENT RECEPTORS ' = 502
  12.4 SINGLE AND / OR MULTIPLE RECEPTORS FOR EACH BASIC TASTE = 503
    12.4.1 Neurophsiological studies = 503
    12.4.2 Psychophysical studies = 504
      12.4.2.1 Threshold studies = 504
      12.4.2.2 Taste of mixtures = 505
        Sweetness versus saltiness = 508
        Sweetness versus sourness = 510
        Sweetness versus bitterness = 512
      12.4.2.3 Adaptation studies = 512
    12.4.3 Chemical studies = 513
    12.4.4 Mathematical models = 514
    12.4.5 The ehiral nature of taste = 515
  12.5 SINGLE AND / OR MULTIPLE RECEPTORS WITHIN EACH BASIC TASTE = 516
    12.5.1 Neurophysiological studies = 516
    12.5.2 Psychophysical studies = 517
      12.5.2.1 Adaptation studies = 518
      12.5.2.2 Taste of mixtures = 519
    12.5.3 Chmical studies, Including synergism = 520
  12.6 GENERIC RECEPTOR MODEL FOR TASTE = 523
Epilogue = 526
Glossary = 530
References = 539
Author Index = 571
Subject Index = 580