Screening of low-alcohol mulberry wine yeast and optimization of fruit wine fermentation process

In order to solve the problems of weak aroma and thin taste of low-alcohol mulberry wine, fruit wine was prepared by grain-fruit blending method using mulberry and malt as main raw materials. Using sensory score and physicochemical indexes of the fruit wine as the evaluation indexes, the yeasts suitable for fermentation of low-alcohol mulberry wine was screened. The fermentation process of the fruit wine was optimized by single factor and orthogonal tests, and the flavor substances in the fruit wine were detected by GC-MS. The results showed that Saccharomycopsis fibuligera N4 was the most suitable strain for the fermentation of low-alcohol mulberry wine, and the fermented wine was more typical in terms of aroma and taste. The optimal fermentation conditions were as follows: fermentation temperature 26 ℃, inoculum 3.0%, initial sugar content 16 °Bx, and the volume ratio of mulberry pulp to wort 4∶1. Under these conditions, the sensory score of the low-alcohol mulberry wine was 89.82, the alcohol content was 5.6%vol, the soluble solids was 6 °Bx, and the reducing sugar content was 2.21 g/L. The body was reddish purple, with the typical aroma of mulberry fruit wine, slightly malt aroma, and rich, coordinated and comfortable mouthfeel. The results of the GC-MS analysis showed that a total of 37 kinds of volatile flavor substances were detected, including phenylethanol with rose-like aroma, amyl acetate with banana aroma, and pineapple ketone with pineapple aroma, and other flavor substances. The study had a certain reference value for improving the quality of low-alcohol mulberry fruit wine.