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, beta-glucosidase activity, ethyl carbamate production, volatile compounds of resulted wines, along with the relationship of beta-glucosidase activity on ethyl carbamate and volatile compounds. beta-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 beta-glucosidase (0.426*) whereas less affected by physicochemical indices of hawthron wines. Volatile compounds were not correlated with beta-glucosidase activity whereas related to the physicochemical indices. alpha-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 beta-glucosidase activity, moderate amounts of volatile compounds, best sensory score and lower EC (5.48 mu g/L).

Automated summary

This study investigated the fermentation characteristics, enzymatic activity, and product features of different commercial yeasts in hawthorn wine. The results showed that the yeast characteristics were closely related to the product features, with FC9 yeast performing the best in hawthorn wine production.