Impact of autoinducer-2 activity on quality characteristics and bacterial community of fermented sausage

The quality of fermented sausages is significantly influenced by microbial metabolism, with quorum sensing serving a crucial regulatory role. This study investigated the impact of exogenous autoinducer-2 (AI-2) activity on the functional properties of Limosilactobacillus fermentum 332 and the quality of fermented sausages. The results showed that adding AI-2 at concentrations up to 100 μmol/L enhanced the hydroxyl radical scavenging and anti-lipid peroxidation abilities of L. fermentum 332, while decreasing AI-2 activity increased the nitrite degradation rate. Elevated AI-2 activity enhanced sausage texture, reduced water activity, and increased lightness (L^⁎ values), whereas reduced AI-2 activity promoted the enrichment of Limosilactobacillus and Lactiplantibacillus, activating metabolic pathways related to carbohydrate, lipid, and amino acid metabolism. This resulted in increased levels of key volatile flavor compounds, including ethyl hexanoate, linalyl acetate, and ethyl oleate. These findings underscore AI-2's critical role in regulating lactic acid bacteria metabolism, providing insights into improving the quality and sensory characteristics of fermented sausages.