The influence of tannin and tannin with salivary protein on the volatility and the perceived intensity of ethyl hexanoate in a wine-like solution

Abstract

The present study investigated the influence of tannin and tannin-mucin interaction on the volatility and the perceived aroma intensity of ethyl hexanoate at 300 µg/L. Data from the instrumental analysis showed that, without mucin, with the increase of tannin concentration, the headspace concentration of ethyl hexanoate was decreased (from 0 to 0.6 g/L of tannins) and then increased (from 0.6 to 16.2 g/L of tannins), in which at 16.2 g/L of tannins, the headspace concentration of ethyl hexanoate measured by HS-SPME-GC-MS was almost the same as found in the control sample that had no tannin. With mucin added to the samples, at higher tannin concentrations, the influence of tannins on the volatility of ethyl hexanoate was disrupted, resulting in the decreased volatility of ethyl hexanoate in the tannin samples with mucin. Sensory experiments were carried out using the method provided by ASTM E679. The results from the sensory experiments illustrated that increasing tannin concentration significantly increased the proportion of panelists (n=36, at 5% significant criterion) correctly choosing the tannin sample as the odd sample. The addition of mucin did not significantly change the sensory responses from the panelists. The group best estimated threshold (BET) values obtained before and after the addition of mucin did not show a significant difference (P>0.05). Therefore, it seemed that the perception changes detected by the panelists were not the result by the changes in the volatility of ethyl hexanoate.