Combined effects of fermentation temperature and Saccharomyces cerevisiae strains on free amino acids, flavor substances, and undesirable secondary metabolites in huangjiu fermentation.

Fermentation temperature (FT) is one of the most critical factors, which can be used to control the growth conditions of S. cerevisiae to obtain excellent final products in winemaking. In this study, we analyzed the responses of six S. cerevisiae strains with different temperature preferences to FT (20 °C, 30 °C, and 35 °C) in huangjiu fermentation. The flavor substances, free amino acids and undesirable secondary metabolites related to huangjiu quality were determined. Results indicated that both S. cerevisiae strains and FT had significant effects on huangjiu fermentation, while the effects were strain-independent and differentiated temperature preferences for different fermentation characteristics. We found that the effects of FT were greater than that of S. cerevisiae strains under the premise of satisfying fermentation completion. Low temperature (20 °C) and high temperature (35 °C) fermentation were possible in the production of differentiated industrial huangjiu styles, while the effects of FT on undesirable secondary metabolites needed to be considered before industrial application. The results showed that a combination of FT with one or more S. cerevisiae strains could be used as a fermentation starter in huangjiu production for different types of products.