Effects of the yeast endogenous β-glucosidase on hawthorn (Crataegus pinnatifida Bunge) wine ethyl carbamate and volatile compounds

In this study, twenty-three commercial yeasts were inoculated into hawthorn ( Crataegus pinnatifida , Bunge (Rosaceae)) extracted juice to explore their fermentation characteristics, β-glucosidase activity, ethyl carbamate production, volatile compounds of resulted wines, along with the relationship of β-glucosidase activity on ethyl carbamate and volatile compounds. β-Glucosidases were yeast and culture medium dependence. However, their activities in wines were merely 9.50 %–30.7 % of that in YM (yeast extract, malt extract) medium. Ethyl carbamate, which was also yeast dependence, was correlated with β-glucosidase (0.426*) whereas less affected by physicochemical indices of hawthron wines. Volatile compounds were not correlated with β-glucosidase activity whereas related to the physicochemical indices. α-Terpineol, which was originally existed in the juice, was increased by the fermentation, while (-) linalool oxide, rose oxide, linalool, terpinen-4-ol, citronellol and nerolidol were newly produced during fermentation. FC9 was the most optimal yeast for hawthorn wine making because of its excellent ethanol production, higher β-glucosidase activity, moderate amounts of volatile compounds, best sensory score and lower EC (5.48 μg/L).