Sensory and physicochemical impact of proanthocyanidic tannins on red wine fruity aroma

Abstract

AIM: Previous research on the fruity character of red wines highlighted the role of esters [1]. Literature provides evidence that, besides these esters, other compounds that are not necessarily volatiles may have an important impact on the overall fruity aroma of wine, contributing to a masking effect [2][3]. 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.

METHODS: Sensory analysis of numerous aromatic reconstitutions in dilute alcohol solution, including triangular tests, detection thresholds, and sensory profiles, were conducted in order to evaluate the sensory impact of tannins on red wines esters 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 which were correlated with sensory results

RESULTS: Triangular test revealed a significant odor difference between a fruity pool containing esters and the same fruity pool in mixture with proanthocyanidic tannins. The establishment of particular “detection thresholds” revealed that the “detection threshold” of the fruity pool was lower in dilute alcohol solution alone than when supplemented with tannins what demonstrated that tannins had a masking effect on the perception of the fruity pool. Sensory profiles evaluation, showed that the average scores for fruity notes were significantly lower for the fruity pool supplemented with tannins. These results confirmed the sensory importance of tannins. Finally, the evaluation of esters partition coefficient revealed a decrease of the volatility of esters when tannins were present in the matrix, thus corroborating sensory evaluation results.

CONCLUSIONS:

Presence of proanthocyanidic tannins decrease esters volatility, thus reducing orthonasal taster stimulation and consequently impacting red wine fruity notes perception.