Proceedings of the 16th Weurman Flavour Research Symposium E. Guichard & J.L. Le Quéré (Eds): Proc. 16th Weurman Flavour Research Symposium, 2021. DOI: 10.5281/zenodo.5946914 Impact of non-volatile compounds on volatiles perception: How proanthocyanidic tannins affect red wine fruity aroma? MARGAUX CAMELEYRE, Georgia Lytra and Jean-Christophe Barbe 1Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, Université de Bordeaux, F33882 Villenave d’Ornon France margaux.cameleyre@wanadoo.fr Abstract Previous research on the fruity character of red wines highlighted that the perception of a “fruity pool” of esters was modified by the presence of fruity or non-fruity compounds with synergistic and/or masking effects. Moreover, some works described that non-volatile compounds may have an important impact on wine perception, but also on odorant compounds volatility. The goal of this work was to assess the olfactory consequences of a mixture between esters and proanthocyanidic tannins, through sensory and physico-chemical approaches. Sensory analyses including triangle tests, detection thresholds, and sensory profiles, were conducted in order to evaluate the sensory impact of pure tannins on red wines “fruity pool” perception. Then, the impact of these non-volatile molecules on esters volatility, and thus taster stimulation, was evaluated thanks to the determination of partition coefficients. Triangular test revealed a significant difference on global perception between the fruity pool containing esters and the same fruity pool in mixture with proanthocyanidic tannins. Sensory profiles evaluation showed fruity notes perception were significantly lower for the fruity pool supplemented with tannins compared to the fruity pool alone in dilute alcohol solution. These results confirmed the sensory importance of some non-volatile compounds on odour perception. Finally, esters partition coefficient evaluation revealed a decrease of the volatility of esters when tannins were present in the matrix, thus corroborating sensory evaluation results. Proanthocyanidic tannins decrease esters volatility when they are added in the matrix, thus reducing orthonasal taster stimulation and consequently reducing red wine fruity notes perception. Such a study should be extended to other wine tannins and anthocyanins, including their concentration ranges, to assess the impact of the phenolic matrix on red wines aroma perception. Keywords: red wine, fruity aroma, non-volatile matrix, perceptive interaction Introduction Wine is a very complex aromatic matrix, composed of more than a thousand volatile compounds. This diversity of chemical families gives wine its tremendous aromatic complexity [1]. In red wines, Pineau et al. (2009) showed that at least part of the fruity aroma of red wines resulted from perceptive interactions between several aromatic compounds, particularly ethyl esters and acetates, even if they were present at concentrations below their olfactory thresholds [2]. Thus, these authors identified a 13-ester fruity pool that characterized Bordeaux red wine aromas. Many other examples of perceptive interactions have been highlighted, with synergistic or masking effects on the fruity aromatic expression of wines [3, 4]. The perception of volatiles during sensory analysis is strongly related to the distribution of aromas between the matrix and the gas phase, and may be related to perception during food consumption; thus, the composition of the matrix may considerably influence the rate of release to the gas phase [5, 6]. Various studies have shown the impact of wine compounds on global perception. However, to date, no study has elucidated the role of polyphenols in the fruity perception of red wines, nor in the fruity compounds released from the matrix to the gas phase. Describing the perception mechanism, Berglund et al. (1976) suggested that perceptive interactions occur at four different levels [7]. The first is described as pre-sensory intera