Understanding creaminess perception of dairy products using free-choice profiling and genetic responsivity to 6-n-propylthiouracil

Flavor and texture contribute to the perception of creaminess in dairy products, but the nature of this interaction is not well understood. Previous studies on the genetic ability to perceive the bitter compound 6-n-propylthiouracil (PROP) reveal the existence of individual differences in creaminess perception. The objective of the present study was to use PROP-classified subjects to gain insight into this individual variation to better understand the cues for creaminess in dairy products, and to ascertain the contributions of flavor and texture to the integrated perception of creaminess. Ten nontasters and 10 supertasters of PROP participated in the study. Subjects evaluated nine commercial dairy products using Free-Choice Profiling (FCP), a type of descriptive analysis that allows subjects to rate products on individual lists of descriptors. Generalized Procrustes Analysis was used to develop separate consensus spaces for nontasters and supertasters. The models for both groups accounted for ∼54% of the variance in the data and were resolved in two dimensions (a dairy flavor/texture axis and a sweet-sour continuum). The products were arranged in a similar pattern along the dimensions in both models. However, nontasters used a limited number of simple terms (sour, sweet, milky and mouthcoating) to describe the products, whereas supertasters used a more complex vocabulary (rich, buttery, creamy, light, grainy, gritty and sandy). The model for nontasters gave equal weight to the sweet-sour and dairy flavor/texture dimensions (28 and 26% variance, respectively); whereas, the model for supertasters relied more heavily on the dairy flavor/texture dimension (34% variance), and less so on the sweet-sour dimension (20% variance). These data suggest that the overall impression of creaminess was similar for nontasters and supertasters, but the cues the two groups used to judge creaminess differed.