Wine aroma improvement using a β-glucosidase preparation from Aureobasidium pullulans

Area of Science:

• Enology
• Enzymology
• Microbiology

Background:

• Microbial beta-glucosidases are crucial for enhancing wine aroma.
• Limited enzyme activity under winemaking conditions hinders their application.

Purpose of the Study:

• To evaluate the production of beta-glucosidase (Ap-β-gl) from Aureobasidium pullulans.
• To assess the enzyme's suitability for winemaking conditions.
• To investigate its potential in releasing wine aroma compounds.

Main Methods:

• Submerged fermentation was used for enzyme production.
• Enzyme characterization included optimal pH, temperature, stability, and ethanol tolerance.
• Gas chromatography/mass spectrometry analyzed the hydrolysis of glycosidic terpenes.

Main Results:

• Maximum enzyme synthesis occurred after 96 hours with cellobiose.
• Ap-β-gl exhibited optimal activity at pH 5.5 and temperatures of 45°C and 70°C.
• The enzyme demonstrated stability across a wide pH range, low temperatures, and ethanol tolerance.
• Hydrolysis of glycosidic terpenes released significant amounts of free terpenols.

Conclusions:

• Aureobasidium pullulans produces a beta-glucosidase (Ap-β-gl) with characteristics suitable for winemaking.
• Ap-β-gl effectively releases aroma-enhancing terpenols, indicating strong potential for wine applications.