Texture Measurement of Foods

Even before the publication of Special Technical Publication 433 of the American Society for Testing and Materials, it became obvious that the brief treatment given to the principles and techniques for sensory measurement and analysis of texture in that volume was all too brief; hence, a task force of ASTM Committee E-18 was formed to develop an authoritative and comprehensive volume on this most complex and important subject to provide within one cover for the student, researcher, and the food manufacturer, a definition and an understanding of the subject offood texture, as well as sensory and objective methods for its measurement. This most difficult task appeared to be possible only after the task force had obtained the assistance of special ists in the many disciplines involved, and after deciding to limit the dissertation to the measurement of texture of foods only. The task was further clarified when Dr. Finney proposed an outline of six chapters, beginning with one on definition. The second chapter was to be on principles of sensory evaluations, the third on sensory measurements, the fourth on principles of objective evaluation, the fifth on objective measurements, and the final concluding chapter on subjective-objective analogues. The first drafts of these six chapters constituted a symposium on texture presented before a joint session at the 1971 Annual Meeting of the Institute of Food Technology and the American Society for Testing and Materials.

Inhalt
I / Food Texture Definition, Measurement and Relation to Other Food Quality Attributes.- 1. Introduction.- 2. Classification.- 3. Definition.- 4. Measurement.- 4.1. Sensory Quality and Sensory Measurement.- 4.2. Accuracy of Objective Methods.- 4.3. Precision of Objective Measurements.- II / Physiological Aspects of Texture Perception, Including Mastication.- 1. Introduction.- 2. Physiological Basis of Mastication.- 2.1. General.- 2.2. Forces and Deformations Occurring in the Mouth.- 2.3. Chewing-Swallowing Patterns.- 2.4. Tactile Sense Organs and Their Function.- 3. Psychological Implications.- 3.1. Relations Between Instrumental and Sensory Data.- 3.2. Eating Habits.- III / Sensory Assessment of Textural Attributes of Foods.- 1. Introduction.- 2. Terminology Surveys.- 3. Consumer Methods of Nonoral Texture Evaluation.- 4. Sensory Panel Tests.- 5. Preference/Acceptance Tests.- 6. Discriminatory Tests.- 6.1. Threshold Tests.- 6.2. Difference Tests.- 7. Descriptive Tests.- 7.1. Ranking.- 7.2. Rating or Scoring.- 7.3. Multifactor Rating Scales.- 7.4. Texture Profile.- 8. Summary.- IV / Elementary Concepts of Rheology Relevant to Food Texture Studies.- 1. Introduction.- 2. Preliminary Considerations.- 2.1. Solids and Liquids.- 2.2. Force and Deformation.- 2.3. Stress and Strain.- 3. Types of Material Behavior.- 3.1. Elasticity.- 3.1.1. The Ideal Elastic Solid.- 3.1.2. Elastic vs Textural Characteristics of Foods.- 3.1.3. Strength of Food Materials.- 3.2. Viscosity.- 3.2.1. The Ideal Viscous Fluid.- 3.2.2. Viscosity vs Mouthfeel Characteristics of Foods.- 3.3. Plasticity.- 3.3.1. Ideal Plastic Flow.- 3.3.2. Plastic Flow of Foodstuffs.- 3.4. Viscoelasticity.- 3.4.1. Characterizing Viscoelastic Materials.- 3.4.2. Viscoelastic Characteristics of Foods.- 4. Concluding Remarks.- V / Structure and Textural Properties of Foods.- 1. Introduction.- 2. Importance of Correct Test Conditions for Evaluation of Textural Properties.- 3. Interrelationship of Structure and Textural Properties.- 3.1. Ice Cream.- 3.2. Margarine and Butter.- 3.3. Bread and Baked Cakes.- 3.4. Fluid Foods.- 3.5. Fruits and Vegetables.- 3.6 Meat.- VI / Instrumental Methods of Texture Measurements.- 1. Introduction.- 2. General Considerations.- 2.1. Basic Elements.- 2.2. Destructive vs Non-Destructive Techniques.- 2.3. Classification.- 3. Types of Texture Measuring Devices.- 3.1. Penetrometers.- 3.2. Compressimeters.- 3.3. Shearing Devices.- 3.4. Cutting Devices.- 3.5. Masticometers.- 3.6. Consistometers.- 3.7. Viscometers.- 3.8. Extrusion Devices.- 3.9. Miscellaneous.- 3.10. Multiple-Purpose Units.- 4. Standardization of Instruments.- 5. Current Trends.- Appendix 1. Named Instruments Described in the Literature.- Appendix 2. Commercially Available Instruments.- VII / Indirect Methods of Objective Texture Measurements.- 1. Introduction.- 2. Chemical.- 2.1. Moisture Content.- 2.2. Alcohol Insoluble Solids (AIS).- 2.3. Fibrousness.- 2.4. Crude Fiber.- 2.5. Connective Tissue.- 3. Enzymatic.- 4. Microscopic.- 4.1. Non-Staining Techniques.- 4.2. Histological Methods and Staining Techniques.- 5. Physical.- 5.1. Density.- 5.2. Volume.- 5.3. Cell Structure and Openness.- 5.4. Drained Weight.- 5.5. Drip.- 5.6. Press Fluid.- 5.7. Miscellaneous.- 6. Concluding Remarks.- VIII / Psychophysical and Psychometric Measures of Texture.- 1. Introduction.- 2. Dimensions of Perceived Texture.- 3. Scales of Magnitude in Texture.- 4. Interval Scales of Texture Perception.- 5. Ratio Scales of Sensory Texture.- 6. Applications of Sensory Scales of Magnitude.- 7. Outlook.- IX / Quantification of Objective and Sensory Texture Relations.- 1. Introduction.- 2. General Considerations.- 3. Methods for Expressing Relationships.- 4. Correlation and Regression.- 4.1. Scatter Diagrams.- 4.2. Correlation vs Regression Analysis.- 4.3. Improving the Correlation.- 4.4. Rank Correlation.- 5. Multiple Regression.- 6. Non-Linear Relationships.- 7. Sources of Variation.- 7.1. Methods of Fitting Constants.- 7.2. Modification of the Experimental Material.- 7.3. Data Analysis.- 7.4. Correcting for Panel Variability.- 8. Prediction.- 8.1. Correlation and Regression Analysis.- 8.2. Response Surfaces Method.- 9. Analytical, Integrative and Sensory Texture 'Interfaces'.- 10. Interaction Between Texture and Other Quality Attributes.- 11. Recent Approaches.- 11.1. Building of Models.- 11.2. Selection of Test Conditions.- 11.3. 'Isoyphs' Method.- 11.4. Representation in Space.- 11.5. Analysis of Several Associated Dependent Variables.- 12. Conclusions.- General Bibliography by M. C. Bourne.