Bourne, Malcolm

Food Texture and Viscosity : Concept and Measurement

Preface to the Second Edition xv Texture, Viscosity and Food Introduction 1(1) Importance of Texture 2(2) The Vocabulary of Texture 4(2) Texture and Time of Day 6(1) Defective Textures 7(1) Textural Diversity 8(3) Status of Food Texture Measurements 11(1) Definitions of Texture 12(4) Texture-related Concepts and Their Definitions 16(1) Texture Versus Viscosity 17(1) Texture and Food Processing 18(3) Texture and Health 21(1) Texture and Structure 22(1) Rheology and Texture 22(4) Early History 26(4) Suggestions for Further Reading 30(3) Body--Texture Interactions Introduction 33(1) Importance of the Tactile Sense 34(1) Some Definitions 35(8) The Sequence of Mastication 43(2) Methods and Processes Used for Disintegration of Food 45(3) Rate of Compression between the Teeth 48(1) Soothing Effect of Mastication 49(1) Saliva 49(1) Forces Generated between the Teeth and Palate 50(3) Tracking Food Movement Within the Mouth 53(1) Reasons for Masticating Food 53(2) Nonoral Methods for Sensing Texture 55(4) The Hand 55(2) Sight 57(1) Sound 57(2) Physics and Texture Introduction 59(2) Deformation 61(3) Effect of Lubrication 64(1) Time Aspects of Deformation 65(3) Materials Science 68(3) Young's Modulus 68(1) Shear Modulus 69(1) Bulk Modulus 69(1) Poisson's Ratio 70(1) Interrelations Between Moduli 70(1) Creep Compliance 71(2) Viscosity 73(5) Laminar Flow and Turbulent Flow 73(2) Dynamic Viscosity 75(1) Fluidity 76(1) Kinematic Viscosity 76(1) Relative Viscosity 76(1) Apparent Viscosity 77(1) Shear Stress 77(1) Shear Rate 77(1) Factors Affecting Viscosity 78(3) Temperature 78(1) Concentration of Solute 79(1) Molecular Weight of Solute 80(1) Pressure 81(1) Suspended Matter 81(1) Types of Viscous Behavior 81(6) Newtonian 81(1) Non-Newtonian Fluids 82(1) Plastic (or Bingham) 82(4) Pseudoplastic 86(1) Dilatant Flow 86(1) The General Equation for Viscosity 87(1) Other Flow Equations 88(4) The Power Equation (also known as the Ostwald-de Wael model) 89(1) Herschel--Bulkley Model 89(1) Casson Equation 89(2) Structural Viscosity 91(1) Time Dependency 92(3) Weissenberg Effect (Normal Force) 95(1) Viscoelasticity 96(2) Small Amplitude Oscillatory Testing (SAOT) 98(2) Mechanical Models 100(1) Fracture 101(2) Stress Concentration 102(1) Isotropy and Anisotropy 103(1) Units of Measurement 104(2) Suggestions for Further Reading 106(1) Principles of Objective Texture Measurement Introduction 107(6) Fundamental Tests 108(2) Empirical Tests 110(1) Imitative Tests 111(2) Force Measuring Instruments 113(34) Puncture Test 113(1) Theory of the Puncture Test 114(9) Semi-infinite Geometry 123(1) Base Support for Puncture Test 124(1) The Punch and Die Test 124(1) Factors Affecting the Puncture Test 125(1) Advantages of the Puncture Test 126(1) Compression-Extrusion Test 127(7) Nozzle Extrusion 134(1) Pros and Cons of the Back Extrusion Test 134(1) Cutting-Shear Test 134(4) Compression Tests 138(1) Uniaxial Compression 138(2) Bulk Compression 140(1) Tensile Tests 140(2) Torsion 142(3) Bending and Snapping Test 145(2) Distance Measuring Instruments 147(19) Linear Measuring Instruments 147(1) Penetrometer 148(2) Rebound Distance 150(2) Deformation 152(2) Geometry of the Test Speciman 154(4) Deformation by Acoustics 158(2) Slump Test 160(2) Gravity Current Flow 162(1) Area Measuring Instruments 163(1) Particle Size Distribution 163(1) Volume Measurement 164(2) Time Measuring Instruments 166(1) Work, Energy and Power Measuring Instruments 166(1) Ratio Measuring Techniques 167(1) Multiple Variable Instruments 168(1) Chemical Analysis 169(1) Miscellaneous Methods 170(7) Optical Methods 170(1) Sound 171(1) Ultrasound Tests 172(1) Rollability 172(1) Electromyography 173(1) Electropalatography 174(1) Multiple-point Sheet Sensor (MSS) 174(1) Fractal Analysis and Fast Fourier Transform 174(1) Imperfect Lubricated Squeezing Flow 175(1) Sliding Pin Consistometer (SPC) 176(1) Pendulam Impact Test 176(1) Universal Testing Machines (UTM) 177(5) Speed of Data Acquisition 178(4) Texture Profile Analysis (TPA) 182(5) Accuracy and Precision of Measurement 187(2) Practice of Objective Texture Measurement Introduction 189(1) Force Measuring Instruments 189(24) Hand-Operated Puncture Testers 189(9) Mechanical and Motorized Puncture Testers 198(1) Bloom Gelometer 198(1) Stevens LFRA Texture Analyzer 198(1) Maturometer 199(1) Christel Texture Meter 200(1) Armour Tendrometer 200(1) Other Puncture Testers 201(1) Compression-Extrusion Testers 201(1) FMC Pea Tenderometer 201(1) Texture Press 202(4) Ottawa Pea Tenderometer 206(1) Vettori Manghi Tenderometro 207(1) Firm Tech 2 207(1) Cutting--Shear Test 207(1) Warner--Bratzler Shear 207(3) Pasta Firmness 210(1) Torsion Devices 210(1) Farinograph 211(1) Mixograph 212(1) Bending 212(1) Structograph 212(1) Tensile Testers 212(1) Extensograph 212(1) FTC Texture Test System 213(1) Distance Measuring Instruments 213(11) Bostwick Consistometer 213(2) The Hilker--Guthrie Plummet 215(1) Ridgelimiter 215(1) Penetrometer 216(3) SURDD Hardness Tester 219(1) Haugh Meter 220(2) Baker Compressimeter 222(1) Adams Consistometer and Tue Cream Corn Meter 223(1) USDA Consistometer 223(1) Volume Measuring Instruments 224(2) Loaf Volume Meter 224(2) Succulometer 226(1) Time Measuring Instruments 226(1) BBIRA Biscuit Texture Meter 226(1) Miscellaneous Methods 226(1) Torry Brown Homogenizer 226(1) Multiple Measuring Instruments 227(8) GF Texturometer 227(1) FTC Texture Test System 228(1) Ottawa Texture Measuring System (OTMS) 229(1) Universal Testing Machines (UTM) 229(1) Instron 230(1) TA.XT2 Texture Analyzer 230(1) QTS Texture Analyzers 231(1) Lloyd Texture Analyzer 232(1) Tensipresser 232(3) Viscosity Measurement Introduction 235(1) Capillary Type 235(6) Tube Viscometry 241(1) Orifice Type 242(1) Coaxial Rotational Viscometers 242(3) Cone and Plate and Parallel Plate Viscometers 245(1) Modes of Operation of Rotational Viscometers 246(1) Other Rotational Viscometers 247(1) Paddle Viscometry 248(2) Falling-Ball Viscometers 250(2) Oscillation Viscometry 252(1) Imperfect Lubricated Squeezing Flow 253(1) Back Extrusion Viscometry 253(2) Imitative Viscometers 255(1) Use of One-Point Measurements for Non-Newtonian Fluids 255(1) Suppliers of Rotational Viscometers 255(2) Sensory Methods of Texture and Viscosity Measurement Introduction 257(1) Importance of Sensory Evaluation 257(2) Sensory Texture Profiling 259(17) Selection of Panel Members 259(1) Training of the Panel 260(2) Establishing Standard Rating Scales 262(1) Mechanical Characteristics 262(5) Geometrical Characteristics 267(1) Other Characteristics 268(1) Developing the Basic TPA Score Sheet 268(5) Developing the Comparative Texture Profile Analysis Ballot 273(3) Variations on Sensory Texture Profile Analysis 276(4) Sensory TPA by Consumer Panels 280(1) Repeatability 281(1) The Texture Profile as an Objective Method 282(1) Modifications to Sensory Texture Profile Analysis 283(4) Nonoral Methods of Tactile Texture Measurement 287(4) Use of Sensory Texture Profile Analysis for Nonfood Consumer Products 291(2) Correlation Between Physical Measurements and Sensory Assessments of Texture and Viscosity Introduction 293(1) Two Types of Sensory Assessment 294(2) Psychophysical Models 296(2) Example of a Successful Correlation 298(1) Example of a Variable Correlation 298(2) Matching Sensory Descriptors to Scientific Principles 300(1) Some Physical Properties Are Not Textural Properties 301(2) Effect of Compression Speed 303(2) Uniformity of Sample 305(4) Isotropic Versus Anisotropic Foods 309(1) Effect of Temperature 310(4) Effect of Sample Size 314(1) Integrated Texture Notes 315(3) Some Foods Easily Give High Correlations 318(1) Correlation Graphs 319(4) Commonsense Helps 323(1) Summing Up 323(2) Selection of a Suitable Test Procedure Introduction 325(1) Factors to be Considered 325(4) Instrument of Sensory 325(1) Nature of Product 326(1) Purpose of Test 326(1) Accuracy Required 326(2) Destructive or Nondestructive 328(1) Costs 328(1) Time 328(1) Location 328(1) Eliminate Unsuitable Tests 329(1) Preliminary Selection 329(1) Final Selection 330(2) Refine Test Conditions 332(1) Preparation of the Sample 333(1) Calibration 334(7) Appendix I Suppliers of Texture and Viscosity Measuring Instruments 341(6) Appendix II Effect of Temperature on Texture Measurements 347(6) Appendix III Guidelines and Conditions for Testing Foods 353(16) Table 1 Food Technology Corporation Texture Test System 353(5) Table 2 Instron 358(4) Table 3 TA.XT2 Texture Analyzer 362(7) Appendix IV Examples of Sensory Texture Profiles 369(12) References 381(34) Index 415