Repercussions of Lactiplantibacillus plantarum HYY‐DB9 and Levilactobacillus brevis GIM 1.773 on the degradation of nitrite, volatile compounds, and sensory assessment of traditional Chinese paocai

Summary Paocai, as one of the most widely consumed traditional fermented foods in China, is dominated by lactic acid bacteria (LAB), which exert a significant influence on the dynamics of metabolites, microecological changes, and sensory quality. In this study, five different paocai groups were designed for fermentation using Lactiplantibacillus plantarum HYY‐DB9 (LP), Levilactobacillus brevis GIM 1.773 (LB), a mixture of two LABs (LP + LB), pasteurisation (PST), and natural fermentation (NF). Nitrite content, pH, titratable acidity, viable cell counts (LAB and yeasts), metabolites (organic acids and volatile substances), and sensory evaluation were determined for each group. The results demonstrated that the mixed fermentation with two LABs (LP + LB) significantly reduced nitrite content. Organic acids produced by LAB played a crucial role in the degradation process, particularly lactic acid which exhibited the most pronounced effect on nitrite degradation. Furthermore, artificial inoculation of LAB fermentation resulted in improved taste and flavour of paocai along with increased production of alcohols, esters, and acids compared to traditional natural fermentation. These findings have important implications for enhancing paocai quality control and managing nitrite content while also providing an excellent fermentation agent for fermented paocai.