Fermentation Process Optimization of Strawberry Wine Using the 2-Phenylethanol Tolerant Saccharomyces cerevisiae...

The fermentation of fresh strawberries into fruit wine offers a solution to the seasonal surplus of strawberries. 2-phenylethanol is a key compound influencing the flavor profile of fruit wines, and elevating its content can enhance both flavor complexity and body quality. In this study, we established the optimal process of fermenting strawberry wine using the 2-phenylethanol (3.9 g/L) tolerant S. cerevisiae AFRC01 strain. Under optimal conditions, the 2-phenylethanol content reached 170.06 mg/L, representing a 33% increase compared to the unoptimized process. Wine fermented with S. cerevisiae AFRC01 exhibited reduced astringency and aftertaste alongside enhanced richness and freshness compared with that fermented with S. cerevisiae CICC33253. A further analysis of the gene expression patterns in the 2-phenylethanol synthesis pathway under 2-phenylethanol stress (1.0 g/L) revealed no significant stress-responsive changes in S. cerevisiae AFRC01, suggesting its mechanism of tolerance is minimally associated with regulation of this pathway. Subsequent genome sequencing identified mutations in the glycolytic pathway genes involved in synthesizing phosphoenolpyruvate (the 2-phenylethanol precursor) in S. cerevisiae AFRC01 compared with S. cerevisiae CICC33253. This study provides a foundation for the later promotion and application of 2-phenylethanol tolerant S. cerevisiae AFRC01.