Theoretical Analysis of the Relationship Between Mechanical Hardness and Its Sensory Assessment

ABSTRACT “Hardness” is mainly perceived through the forces that the fingers, jaws or tongue exert. Since the mechanical resistance of the tissues involved is often comparable in magnitude to that of the, tested object, the mechanical sensitivity must decline at a level determined by the resistance of both tissue and object. Sensory response to mechanical stimulus starts at zero, ends up in saturation or pain and ought to have certain mathematical properties. Superposition of the response intensity and the mechanical sensitivity reveals a theoretical relationship between mechanical hardness and its sensory assessment. This relationship implies that scatter in hardness sensory scores is theoretically inevitable and that there must be a certain hardness range for which each organ has maximum sensitivity.