Potential use of grape and wine polysaccharide extracts as fining agents to modulate the volatile composition of Viura wines

Abstract

This paper describes for the first time the use of grape derived polysaccharide extracts as potential fining agents to modulate the volatile composition of Viura white wines. Polysaccharide extracts were obtained from white grape pomace, red wine pomace, white must, red must, white wine, and lees from white wine. Except for higher alcohols, the extracts from white pomace, red pomace and white lees increased the content of most volatile compounds after one and twelve months of bottle aging. They could be used to enhance fruity and floral aromas and reduce unpleasant aromas, showing as good modulators of white wine aroma. The presence of mannoproteins, glucans, non-pectic polysaccharides, and low molecular weight polysaccharides increased the content of most volatile families. Polysaccharides of medium molecular weight showed negative correlations with volatile contents. Our results support the use of winemaking by-products to obtain valuable polysaccharides, contributing to the circular economy.

Keywords: Aroma; Grape-by products; Homogalacturonans; Mannoproteins; Polysaccharides rich in arabinose and galactose; Rhamnogalacturonans.