Time-Intensity Methods

Abstract

In general, humans perceived tastes as changing experiences originating in the mouth, which normally existed for a limited time and then either subsided or traniformed into qualitatively different gustatory perceptions. Taste experiences did not begin at the moment of stimulus arrival in the mouth, did not suddenly appear at full intensity, were irifluenced by the pattern of taste stimulation, and often continued well beyond stimulus removal-Halpern, 1991, p. 95. THE APPROACH AND ITS ADVANTAGES Perception of aroma, taste, flavor, and texture in foods is a dynamic, not a static, phenomenon. In other words, the perceived intensity of the sensory attributes change from moment to moment. The dynamic nature of foods arises from processes of chewing, breathing, salivation, tongue movements , and swallowing (Dijksterhuis, 1996). In the Texture Profile method, for instance, different phases of food breakdown were recognized early on, as evidenced by the separation of characteristics into first bite, mastication, and residual phases (Brandt et al., 1963). Wine tasters often discuss how a wine "opens in the glass," recognizing that the flavor will vary as a function of time since opening the bottle and exposing the wine to air. It is widely believed that the consumer acceptability of different intensive sweeteners depends on the similarity of their time profile to that of sucrose. Intensive sweeteners with too long a duration in the mouth may be less pleasant to consumers. Conversely, a chewing gum with long-lasting flavor or a wine with a "long finish" may be desirable. These examples demonstrate how 265 H. T. Lawless et al., Sensory Evaluation of Food