Improving fermentation efficiency and aroma quality of Shanlan Rice wine: Co-fermentation with selected dominant...

Shanlan Qubing (SLQB) is a traditional fermentation starter used in the production of Shanlan rice wine in Hainan, China. However, the open brewing environment and the complex microbial composition of SLQB often affected instability in fermentation performance and product quality. In this study, the physicochemical properties, enzymatic activities, microbial composition, and volatile characteristics of SLQB were systematically investigated. Dominant functional microorganisms were further selected and applied in co-fermentation to explore a controllable strategy for producing high-quality Shanlan rice wine. The results suggested that SLQB provides favorable physicochemical conditions and enzymatic tools for rice wine fermentation. Phenethyl alcohol and 1-nonanol are characteristic volatile compounds of SLQB, potentially dominated by the metabolism of Rhizopus, Saccharomyces, and Pediococcus. Co-fermentation with the selected Lichtheimia ramosa, Saccharomyces cerevisiae, and Lacticaseibacillus paracasei strains from SLQB is a promising strategy for the directed improvement of Shanlan rice wine fermentation. Among these, co-fermentation with L. ramosa G-1, S. cerevisiae MQ-8, and L. paracasei RMQ-25 was identified as the optimal consortium. Compared with SLQB fermentation, this consortium increased ethanol content from 9.57% to 10.47%, preserved characteristic volatile compounds such as octanol and phenylethyl alcohol, and generated unique volatiles such as isoamyl acetate and ethyl undecanoate. This study can lay a foundation for the quality control of SLQB and Shanlan rice wine.