Multi-step screening of suitable Saccharomyces cerevisiae strain for lemon wine brewing

Currently, most fruit wines are fermented with commercial wine yeasts or universal Saccharomyces cerevisiae strains, which leads to the problems of thin taste, insufficient flavor, and lack of typicality of fruit wine. In this study, one S. cerevisiae strain (NM-8) was isolated from the spontaneous fermentation broth of lemon, and its fermentation characteristics for lemon wine were compared with three commercial S. cerevisiae strains. The results showed that S. cerevisiae NM-8 displayed a good acidity tolerance under pH 3.2 and 2.8, which reached the maximum cell value during lemon wine fermentation. In addition, the lemon wine sample fermented with NM-8 contained more ascorbic acid (48.22 mg/L), sorbitol (0.96 g/L), and glycerin (4.44 g/L), which performed positive effects on the smoothness and sweetness of lemon wine. Moreover, both its total flavonoid content and DPPH radical scavenging activity were the highest, which were 320.72 mg RE/L (expressed as rutin equivalent) and 66.33%, respectively. Meanwhile, Gas Chromatography-Mass Spectrometry, Gas Chromatography-Ion Mobility Spectrometry, and sensory evaluation were used for the comprehensive analysis of the flavor compounds of four lemon wines. It showed that the lemon wine fermented with NM-8 had the highest sensory score, possibly due to the abundance of flavor compounds and their higher odor activity value. In conclusion, the screened strain S. cerevisiae NM-8 isolated from lemon surroundings with stronger acid resistance was able to brew excellent lemon wine with not only higher taste evaluation score but also stronger antioxidant activity, indicating that NM-8 showed substantial advantages in producing lemon wine.