Insights into the quality and safety control of traditional Chinese fermented sausages via dynamic profiling of the microbiota and metabolome

Although microorganisms are essential for the production of traditional fermented sausages (TFS), the relationship between microbial activity, their metabolites, and the safety and quality of the final product remains unclear. To address this, the physicochemical properties (including color, pH, a_w, lipid oxidation, and nitrite residue), microbiome composition, and metabolome of TFS were analyzed at different ripening stages (D1, D3, D5, D15, and D25). The findings indicated that D15 represents a critical turning point in the physicochemical parameters of Chinese TFS during ripening, thus delineating two distinct fermentation stages: an former stage (D1 to D15) and a later stage (D15 to D25). Moreover, the microbial communities and metabolic profiles differed markedly between these two phases. Lipid-derived metabolites were predominant during the early phase, whereas proteolytic substances dominated in the later phase. In particular, the genus Weissella showed positive correlations (absolute r > 0.45, p < 0.05) with lipid metabolites such as sphingosine, oleic acid, and linoleic acid, and negative correlations with toxins including 5-fluorouridine, penicillin, and indole. Conversely, Shewanella exhibited the opposite pattern. Thus, Weissella and Shewanella appear to be key microorganisms that significantly influence the quality and safety of TFS by modulating lipid and toxin metabolism. These results contribute to a deeper understanding of the mechanisms underlying quality and safety control in Chinese TFS and provide theoretical support for the future development of healthier fermented meat products. Nevertheless, further validation studies are necessary.

Graphical abstract