chapter  7
Food Psychorheology
A Speculation on Difficulties
ByBirger Drake
Pages 8

People who say that food rheology is difficult "because we make it difficult," can be content with having useful descriptions, appropriate tools, and functioning procedures. The permanent importance of rheological attributes is emphasized by Galen's mentioning of the tactile concepts of hardness and softness, stickiness and brittleness, and compactness and porosity. Foods are often inhomogeneous and can have an inner structure that defies our efforts at a true description. A single food structure may behave in a "fractoviscoelastoplastic" way. Handling and chewing foods involves a complicated feedback procedure, in which forces and deformations unconsciously determine each other in rapid succession. Foods are normally consumed under full sensory control, and food texture, resembling food color, food taste, etc., is a typical sensory attribute. Food rheology, therefore, cannot be detached from psychometrics and other branches of the behavioral sciences, of which none is self-evident.