Beta-glucosidase activity of wine yeasts and its impacts on wine volatiles and phenolics: A mini-review

Beta-glucosidase is an important enzyme for the hydrolysis of grape glycosides in the course of winemaking. Yeasts are the main producers of β-glucosidase in winemaking, therefore play an important role in determining wine aroma and flavour. This article discusses common methods for β-glucosidase evaluation, the β-glucosidase activity of different Saccharomyces and non- Saccharomyces yeasts and the influences of winemaking conditions, such as glucose and ethanol concentration, low pH environment, fermentation temperature and SO2 level, on their activity. This review further highlights the roles of β-glucosidase in promoting the release of free volatile compounds especially terpenes and the modification of wine phenolic composition during the winemaking process. Furthermore, this review proposes future research direction in this area and guides wine professionals in yeast selection to improve wine quality.