On fundamental issues in texture evaluation and texturization—A view

Irrespective of the geometry and other factors, the human motor sensory system creates and processes signals in a manner that is qualitatively different from those produced by stiff mechanical testing machines. This is primarily because the tissues own deformability and rheological properties play a major role in the stimulus generation. Consequently, and unlike in man-made machines operating in their designed load range, the sensory sensitivity depends on both the rheological properties of the tissues involved and those of the specimen. Also, the sensory response to a mechanical stimulus is non linear and can be affected by adaptation and fatigue. Sensory evaluation and material science have different vocabularies and many sensory textural attributes are difficult to express in universal mechanical terms. It is, therefore, proposed to deepen the involvement of material science in texture studies and to relate the distribution of sensory responses to well defined and measurable mechanical properties like stiffness, toughness, elasticity and brittleness.Since textural differences are frequently accompanied by other organoleptic differences, hydrocolloids offer a unique way to create and control the mechanical properties of model and real foods with minimal effect on their flavor and color. Such foods, at least in principle, can reveal how mechanical properties are perceived. They can also help establish the human sensitivity to various mechanical properties thus helping the food industry not only to create and control desirable textural characteristics, but also to establish rational tolerance margins to the mechanical properties of its products.