Operational Conditions and the Stress‐strain Relationship of Solid Foods—theoretical Evaluation1

Many textural evaluation techniques are based on test procedures that involve large compressive deformations and constant deformation rates. These imply that the specimen undergoes a straining history which depends on the specimen length and in which the true strain rate increases progressively. Mathematical simulation of the real conditions in simplified rheological models indicated that single stress‐strain curves may provide misleading information on the true characteristics of the material. I t is shown that the stress‐strain curves of different materials can cross one another a t stmin levels that depend on test conditions. Any comparison under such circumstances may result in inconsistent conclusions. It is suggested that relaxation data may provide the complementary information for the comprehensive characterization of the mechanical properties of foods.