Abstract: The volatile flavor compounds of Chinese cabbage pickle fermented with Lactobacillus casei 11MZ-5-1, isolated from naturally fermented Chinese cabbage brine, and the naturally fermented sample were analyzed by high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Meanwhile, the bacterial communities were investigated. It was found that L. casei 11MZ-5-1 fermented pickle contained higher total acid content and lower nitrite content than the naturally fermented one. The contents of the health-beneficial metabolites glycerine, mannitol, 2,3-butanediol and VC were (0.36 ± 0.03), (13.82 ± 0.42), (0.22 ± 0.02) g/L and (445 ± 13.23) mg/kg, respectively, and the relative content of flavor compounds was (91.13 ± 4.29)% in the L. casei 11MZ-5-1 fermented pickle, which were all higher than those in naturally fermented pickle (P < 0.05). These results demonstrated that the 11MZ-5-1 fermented Chinese cabbage pickle were better in term of safety and nutritious value in addition to higher contents of flavor compounds and better sensory quality. Furthermore, the bacterial diversity in the 11MZ-5-1 fermented product was lower than that in the naturally fermented sample (P < 0.05), and L. casei dominated the microbial flora during the fermentation process. Our findings highlight the application potential of L. casei 11MZ-5-1 as a starter culture for industrial production of Chinese cabbage pickle and could be useful for monitoring the production of pickled Chinese cabbage and establishing quality standard.

Key words: pickled Chinese cabbage, Lactobacillus casei, chemical composition, bacterial diversity