Mixed-fermentation effects of co-fermentation with Hanseniaspora uvarum and Saccharomyces cerevisiae on the flavor quality of Ziyan tea wine.

Ziyan tea wine is an anthocyanin-rich fermented beverage with distinctive colour and flavor. In this study, we compared single and mixed yeast fermentation. Co-fermentation with S. cerevisiae and Hanseniaspora uvarum at a ratio of 1:1 significantly increased the sensory score compared with S. cerevisiae monoculture. Enartis Ferm Aroma White and H. uvarum at a ratio of 1:2 also produced a high sensory score, but the difference from Enartis Ferm Aroma White monoculture wasn't significant. HS-SPME-GC-MS and spectrophotometric analyses showed that co-fermentation changed the volatile profile of Ziyan tea wine. Some co-fermentation treatments had higher levels of floral and fruity aroma compounds (e.g., nerol, isoamyl acetate) and lower levels of volatile acids (e.g., nonanoic acid, octanoic acid), leading to a more balanced fruity and floral aroma profile. Overall, co-fermentation changed the volatile composition and sensory properties of Ziyan tea wine and may provide a useful method for improving tea wine quality.