Temporal accumulation of biogenic amines and the succession of microbial communities during the soybean paste...

Soybean paste enjoys favor among consumers for its rich taste and unique flavor profile, but the biogenic amines (BAs) content and microbial community structure during its fermentation process remain unclear. This study aimed to explore the dynamic alterations of BAs, physicochemical properties, and microbial community succession during soybean paste fermentation. The results revealed that the total BA concentration reached the highest level of 238.90 mg·kg^-1 on the 14th day of fermentation. A total of seven types of BAs were identified throughout the fermentation stage, with histamine concentration ranking first among all BAs. The production of key BAs like histamine and tyramine can be enhanced by salt concentration, total acid, and amino acid nitrogen. Ligilactobacillus and Staphylococcus were the core genera in the bacterial community, while Aspergillus and Zygosaccharomyces were the main genera in the fungal community. A notable positive correlation was found between Variovorax and Enterococcus and tyramine content, while Histamine and octopamine synthesis was primarily attributed to Exophiala and Ligilactobacillus. These findings will help understand the formation mechanism of BAs that are present in soybean paste, thereby ensuring the safe production of soybean paste.