Malodorous compound production driven by microbial succession during Chinese cabbage decomposition

Chinese cabbage is one of the most widely consumed vegetables in China. However, malodorous compounds generated from the decomposition of discarded leaves during harvest and distribution have become a significant environmental concern. This study aimed to identify the key odor compounds produced during Chinese cabbage decompostion and to characterize their associations with microbial community dynamics.

Physicochemical monitoring showed declining total solids and sugars, rising soluble protein, and fluctuating total nitrogen. Gas chromatography-olfactometry-mass spectrometry (GC-O-MS) identified dimethyl disulfide and dimethyl trisulfide as early dominant odorants. The content of dimethyl disulfide increased from 0.53 to 59.29 μg/kg by day 3, while dimethyl trisulfide peaked at 14.08 μg/kg on day 3 and then became undetectable. Indole accumulated to 9.82 μg/kg by day 5 and persisted thereafter, becoming the major malodorous compound in mid-to-late stages. Full-length 16S/ITS sequencing revealed distinct bacterial and fungal succession, with Alcaligenes faecalis dominating (42.25%) at day 11 and Geotrichum silvicola and Candida tropicalis prevailing among fungi. Spearman correlation suggested associations between specific taxa and key odorants. Screening and validation confirmed that Rhodotorula mucilaginosa and Yarrowia lipolytica removed > 99.7% of indole.

Dimethyl disulfide, dimethyl trisulfide, and indole are the principal odor compounds during Chinese cabbage decomposition, with indole dominating the later stages. Microbial succession drives the temporal shift in odor profiles. Rhodotorula mucilaginosa and Yarrowia lipolytica were validated as highly effective indole-degrading agents, highlighting their potential for biological odor mitigation during cabbage decomposition, although their capacity for sulfur-compound removal remains limited. © 2026 Society of Chemical Industry.