Influence of ageing on lees on polysaccharide glycosyl-residue composition of Chardonnay wine

The influence of different ageing conditions on lees, and in particular of lees obtained with and without a rough raking, on polysaccharide glycosyl residues of Chardonnay wine is addressed in this work. Methanolysis and derivatization procedures of ethanol precipitated polysaccharides, followed by gas-chromatography coupled to mass spectrometry, allowed the determination of all the main sugars known to constitute wine polysaccharides. The aging on lees led to an increase of the contents of all the glycosyl residues, except for both galacturonic acid, whose concentration slightly decreased, and glucose and myo-inositol, which were not affected by the ageing process. Results suggest that the use of aging on lees without a rough raking enriched wine of mannoproteins meanwhile contributing to the solubilization of grape polysaccharides more than aging on lees with a rough raking.