Yuhan Zhang

The bacterial microbial community composition during wine fermentation is a key contributor to wine quality and flavor. However, studies on the regulatory effects of different grape varieties and co-fermentation processes on the microbial community structure and their synergistic mechanisms remain limited. In this study, Cabernet Sauvignon (CS) was subjected to single-variety fermentation and used as the base wine for co-fermentation with three other grape varieties—Marselan (CSMN), Merlot (CSMT), and Cabernet Gernischt (CSCG)—to systematically compare the differences in the microbial community composition and their effects on the production of metabolic compounds. The results showed that, compared with single-variety fermentation, co-fermentation significantly increased the α-diversity of microbial communities (the Shannon index increased) and exhibited significant differences in β-diversity (PERMANOVA analysis, R² = 0.421, p < 0.001). A neutral model analysis indicated that co-fermentation had a significant impact on microbial community assembly mechanisms, with the contribution of neutral processes to community assembly increasing from 45.5% (in the CSCG process) to 62.3% (in the CSMT process). A microbial co-occurrence network analysis revealed that co-fermentation enhanced the network complexity of microbial communities and strengthened the synergistic interactions between microbial taxa. A metabolic compound analysis revealed that co-fermentation significantly enhanced the production of key aroma compounds, resulting in increased concentrations of isoamyl acetate, ethyl hexanoate, linalool, and geraniol. These findings highlight the differences in microbial communities and their synergistic mechanisms among co-fermented grape varieties, providing theoretical guidance and practical insights for optimizing co-fermentation processes and improving wine quality.

Potassium bitartrate (KHT) crystallization, as the dominant factor compromising wine colloidal stability, necessitates advanced control strategies beyond conventional thermodynamic approaches. The formation of tartrate crystals is influenced by various factors, including temperature, pH, and the concentration of tartrate salts. Traditional methods of tartrate stabilization, such as cold stabilization and ion-exchange resins, while effective, are associated with high energy consumption and significant environmental impact. In recent years, with the growing emphasis on green and sustainable development, researchers have begun exploring more environmentally friendly innovative technologies. This review examines the factors affecting tartrate crystallization and their implications for wine quality, detailing traditional stabilization techniques as well as newer methods involving protective colloids and stabilizers. Special attention is given to recent advancements in green technologies, such as plasma surface modification, the use of zeolites as wine processing aids, and the synergistic application of algal polysaccharides. Finally, the paper outlines future directions for tartrate stabilization technology, underscoring the importance of green and sustainable practices in the wine industry.