Effects of Aroma Components and Physicochemical Quality of Mulberry Rice Wine Fermented by Two Saccharomyces cerevisiae

Sake yeast and active wine dry yeast were used as fermentation strains. Mulberry rice wine was fermented by five methods,which were inoculated with sake yeast and inoculated active wine dry yeast,two yeasts were inoculated in different order and simultaneous inoculation of two yeasts. The aroma substances of mulberry rice wine were analyzed using gas chromatography-mass spectrometry(GC-MS),and principal component analysis was used to analyze the main aroma components. The results showed that mulberry rice wine fermented by sake yeast for 7 d and then inoculated with active wine dry yeast continued to ferment had better quality. The physicochemical indexes of rice wine were alcohol content(10.10%vol±0.20%vol),residual sugar content(30.70±0.10 g/L),total acid(6.85±0.08 g/L),volatile acid(0.31±0.05 g/L),sensory score(85.60±0.19).A total of 175 aroma components were detected in the five groups,including 62 esters,30 alcohols,8 acids,11 aldehydes,19 ketones,29 hydrocarbons,and 16 other substances. There were 14 kinds of main flavors in the mulberry rice wine fermented by inoculating sake yeast 7 d and then inoculating active wine dry yeast to continue fermentation. Among them,the relative content of typical aroma component beta-phenylethanol reached 17.88%,which was 2.63~3.96 times higher than that of other four fermentation methods,and the rice wine had a strong aroma,fruity,floral and milky aroma.