Skin cell wall ripeness alters wine tannin profiles via modulating interaction with seed tannin during alcoholic fermentation

Abstract

The proportion of seed tannins in wine is higher than that of skin tannins during normal winemaking practices. The interaction between grape skin cell wall and seed tannin could alter seed tannin extraction and wine tannin profiles during winemaking. However, the influence of grape skin cell wall ripeness in the interaction is still unclear. The purpose of this work was to study the influence of grape skins cell wall ripeness on seed tannins extraction and the final wine tannin profiles during alcoholic fermentation. The percentage of seed tannins extraction increases according to the skin cell wall maturity, and the higher the mDP of tannins, the larger the difference of tannins extraction. During alcoholic fermentation, seed tannins are adsorbed to the skin cell wall and desorb gradually into wine. For the final wine, cell wall maturity was positively correlated with tannins concentration and negatively correlated with G%. The results indicate that grape skin cell walls of different ripeness modulate seed tannins profiles in wine by controlling seed tannins release and adsorption-desorption of tannins during alcoholic fermentation.

Keywords: Extractability; Fermentation; Grape; Seed; Skin cell wall; Tannin; Wine.