Sensory Methods of Texture and Viscosity Measurement

Sensory evaluation is the measurement of a product's quality based on information received from the five senses: sight, smell, taste, touch, and hearing. Sensory texture measurement is perceived primarily by touch, although the eyes and ears can provide information on some important components of the total texture profile of a product. Sensory evaluation offers the opportunity to obtain a complete analysis of the textural properties of a food as perceived by the human senses. A number of processes occur while food is being masticated, including deformation, flow, comminution, mixing and hydration with saliva, and sometimes changes in temperature, size, shape, and surface roughness of the food particles. All of these changes are recorded with great sensitivity by the human senses, but many of them are difficult to measure with instruments. Sensory evaluation is important for product development. It is the best method for evaluating texture of new types of foods in the early stages of development, especially fabricated foods, and for providing a basis on which instrumental methods might later be designed for use as a quality measure and production control. The major steps in the operation of establishing a sensory texture profile are (1) selection of panel, (2) training the panel, (3) establishing standard rating scales, (4) establishing a basic texture profile analysis (TPA) score sheet, and (5) developing a comparative TPA score sheet for each commodity.