Natural sun drying process of Rugao sausage: Microbial community succession and its crucial role in flavor development.

This study systematically analyzes the dynamic changes in physicochemical properties, microbial community, and flavor compounds of Rugao sausage during the sun-drying process. It identifies the key microbial species that make a key contribution to flavor formation during drying, while also clarifying the relationship between these species and the key flavor compounds of the sausage. The results showed that as the drying process progressed, the moisture content, water activity, and pH of the sausage gradually decreased, while microbial diversity declined. Microbial communities with stronger environmental tolerance, such as lactic acid bacteria, dominated in the sausage. Among them, 10 species, such as Macrococcus caseolyticus and Lactococcus garvieae, became the dominant species. A total of 30 volatile compounds were identified as key flavor substances related to flavor formation during drying. After excluding flavor compounds derived from spice, these included 8 aldehydes, 2 alcohols, 3 ketones, 4 esters, and 2 aromatic compounds. Correlation analysis further revealed a significant correlation between the microbial community and key volatile flavor compounds during drying. After comprehensive analysis, Lactococcus garvieae, Macrococcus caseolyticus, Streptococcus dysgalactiae, and Streptococcus parauberis were identified as the key microbial species for flavor formation. Among these, Lactococcus garvieae and Macrococcus caseolyticus showed a highly positive correlation with several key volatile flavor compounds. This study elucidates the key functional microorganisms that drive flavor formation in Rugao sausage during the sun-drying process, and the findings provide important theoretical support for optimizing traditional production processes and achieving precise, flavor-guided regulation.