Human oral processing and texture profile analysis parameters: Bridging the gap between the sensory evaluation and the instrumental measurements.

Studies in food oral processing are becoming increasingly important with the advent of the aged society. The food oral processing model of Hutchings and Lillford (Journal of Texture Studies, 19, 1988, 103-115) describes the structural breakdown and lubrication of ingested food before the swallowing stage, and has been revisited in the present article. The instrumental technique texture profile analysis (TPA) purports to mimic the first two bites of mastication and its ease of use has lured some researchers to use it without a critical eye. In this article, we consider inconsistencies in the Hutchings and Lillford model with the hope that it might be further refined. With regard to TPA we question the validity of the data generated and urge authors caution before they publish results from the test protocol. If results are published then the x-axis should be viewed as deformation or strain, and not time. Hardness should be represented by the breaking stress. Adhesiveness should be measured at a medium strain taking into account the surface properties of the plunger. The ratio of the energy estimated by the area under the curve obtained from the second and the first bites (A /A ) should be called recoverability and not cohesiveness.