Wine Aroma Improvement Using a beta-Glucosidase Preparation from Aureobasidium pullulans

Abstract

Microbial beta-glucosidases have been used for the enhancement of wine aroma. Nevertheless, few enzymes are active in the conditions of winemaking. in this work, the production of a beta-glucosidase by an Aureobasidium pullulans strain (Ap-beta-gl) isolated from grape ecosystems was evaluated. the maximum enzymatic synthesis using submerged fermentation was after 96 h of growth in complex media containing 20 g/L of cellobiose as the sole carbon source. the crude enzyme (Ap-beta-gl) showed optimal pH at 5.5 and two peaks of optimum temperature (at 45 and 70 A degrees C). It showed a wide range of pH stability, stability at low temperatures, and tolerance to ethanol, showing suitable characteristics for winemaking conditions. the hydrolysis of glycosidic terpenes by Ap-beta-gl was studied, and its ability to efficiently release free terpenols was demonstrated by gas chromatography/mass spectrometry. the enzymatic treatment notably increased the amount of monoterpenes, showing good prospects for its potential application for the development of aroma in wines.