Hydrolysis and sorption by Saccharomyces cerevisiae strains of Chardonnay grape must glycosides during fermentation

Different Saccharomyces cerevisiae strains were tested for their ability to hydrolyse glycosyl–glucose (G–G) compounds present in Chardonnay must during alcoholic fermentation. The determination of glycosyl–glucose during the course of the alcoholic fermentation of Chardonnay grape must revealed that S. cerevisiae is able to hydrolyse G–G during alcoholic fermentation in wine conditions. The extent of hydrolysis vary from 17 to 57% of the initial glycoside concentration. In order to confirm that decrease in G–G concentration during alcoholic fermentation is due to hydrolytic action and not to sorption phenomenon, in the first experiment, an analysis of the osidic part of Chardonnay must glycosides before and after alcoholic fermentation confirmed the ability of yeast to hydrolyse G–G. In the second experiment, we determined the ability of yeast to sorb G–G. Our results show that no more than 5% G–G were sorbed by yeast.