Insights into the correlation between bacterial community succession and dynamics of biogenic amines during three types of sufu fermentation

The high protein content in sufu provides a substrate for microorganisms to produce biogenic amines (BAs), thereby posing a potential risk to food safety. The aim of this study was to identify the main BAs produced by different types of sufu (red, white and grey sufu) and investigate the relationship between bacterial diversity and BA production using high-throughput sequencing. The results revealed significant differences in the total BA content of the three types of sufu at the post-fermentation stage, with grey sufu exhibiting the highest total BA content (ranging from 6389.00 mg/kg to 7255.49 mg/kg). The main BAs found in all three types of sufu were tyramine, putrescine and cadaverine. Enterococcus genus produced high levels of tyramine and phenylethylamine in all three types of sufu. The predominant cadaverine-producing bacteria in red sufu was Enterobacter genus, whereas Klebsiella pneumoniae was the primary producer of cadaverine in white and grey sufu. Putrescine was primarily associated with the Bacillus and Enterobacter genera in red and grey sufu. Acinetobacter, Enterococcus and Enterobacter were the common dominant genera during the post-fermentation stage of the three kinds of sufu, which were positively correlated with the production of various BAs. These findings will help to understand the mechanism of BAs production by bacterial communities in different types of sufu to ensure safe production.