Tailoring texture for the elderly: theoretical aspects and technological options.

The perception of what is known as "texture" is a result of a variety of primarily mechanical and acoustical events. These are sensed by receptors of different kinds that are unevenly distributed in the sensing organ(s) (tongue, jaws, fingers) and neighboring tissues. The perceived intensity of textural properties is time dependent and can be influenced by other stimuli, notably chemical and thermal. The exact mode in which mechanical and geometrical properties are translated into perceived texture is not known. There are, however, known trends based on empirical observations, and growing understanding of the operation of individual receptors and the physiology and biomechanics of the sensation process itself. This body of knowledge can provide rational guidelines for the development of special products for the elderly and other people with special needs. For example, it is possible to increase fragility and maintain crunchiness or to make chewy foods that require a reduced effort in mastication to minimize fatigue. The technology to make such products is already in place and its future use by the food industry will depend only on marketing opportunities.