Attività Beta-glucosidasica di lieviti isolati da vinacce rosse per la produzione di grappa

"Beta-glucosidase activity of yeasts isolated from red grape marcs destined to Grappa production"

The glucosidasic activity of microorganisms contributes to the aroma of wines and distillates through the hydrolysis of the odorless glycoconjugates compounds, concentrated in the grapes, which release free terpenols and other aromatic compounds . The grappa, a typical Italian alcoholic drink, is obtained from the distillation of marcs, consisting mainly of grape skins, after a period of variable storage. This work was aimed at analyzing the beta-glucosidasic activity of marcs isolated yeast strains from grapes of different origin (Muscat and Prosecco) or subjected to technological processing. The beta-glucosidasic activity was tested using a method, especially developed, based on the emission of a fluorescent signal from a molecule containing a glycosidic bond. The tests were carried out by reproducing the typical conditions of the enological environment and allowed to quantify rapidly the enzyme activity of a large number of yeasts.