Novel contribution to the study of mouth-feel properties in wines

Abstract

In general, there is a well-established lexicon related to wine aroma and taste properties; however mouth-feel-related vocabulary usually includes heterogeneous, multimodal and personalized terms. Gawel et al.
(2000) published a wheel related to mouthfeel properties of red wine. However, its use in scientific publications has been limited. The authors accepted that the approach had certain limitations as it included redundant and terms with hedonic tone and some others were absent. It is of high interest to generate a mouth-feel lexicon and finding the chemical compound or group of compounds responsible for such properties in red wine. In the present work a chemical fractionation method has been developed. Six odorless wine fractions containing groups of compounds with different sensory and chemical properties were isolated. Eighteen fractions (6 fractions x 3 wines) were firstly classified in groups attending to their in-mouth similarities and groups were described (labelled sorting task) by a panel of experts. This task allowed identifying 14 fractions with different in-mouth properties. These odorless fractions were further submitted to a task of vocabulary generation (repertory grid). Terms generated in both sorting task and repertory grid were combined to form categories through a triangulation process. The final list of 23 terms (4 related to taste and 18 to mouth-feel) was employed for the sensory characterization of the 14 fractions by Rate-all-that-apply method with 30 wine experts. ANOVA analyses calculated on the 23 attributes showed significant effects for 20 of them, which confirmed the discrimination ability of the terms and sensory differences among fractions. Further PCA analysis followed by cluster analysis showed 5 groups of fractions with different in-mouth properties: cluster 1 (5 fractions) characterized with terms: sweet, watery, silky, fleshy, oily and greasy; cluster 2 (4 fractions): burning, hot and bitter; cluster 3 (3 fractions): dry, coarse and granular; cluster 4 (1 fraction): dusty and 5 (1 fraction) bitter, sour, puckering, persistent and sharp.