Integrated multi-omics elucidates the microbial-metabolite interplay governing antioxidant capacity in mung bean sour liquid.

Background: Mung bean sour liquid (MBSL) is a traditional fermented food, yet the microbial-metabolic basis of its antioxidant capacity is unclear. This study employed integrated metagenomics and metabolomics to elucidate the dynamic formation of antioxidant biomarkers during fermentation.

Results: The mid-fermentation stage (6-12 h) was critical for antioxidant development, marked by peak accumulation of key biomarkers such as phenyllactic acid, epigallocatechin and catechin. Antioxidant activity [2,2-diphenyl-1-picrylhydrazyl/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] (DPPH/ABTS) significantly increased during this period, reaching 77.4% and 74.5% by 24 h. These changes were directly correlated with specific Lactobacillus spp. (e.g. Lactobacillus curvatus and Lactobacillus mudanjiangensis). Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed stage-specific metabolic reprogramming, from early activation of amino acid/lipid metabolism to late-phase downregulation of central carbon metabolism. Correlation networks further linked these Lactobacilli to key carbohydrate-active enzymes (CAZy), such as glycoside hydrolases.

Conclusion: This study decipheedr the microbial-driven metabolomic remodeling that governs antioxidant capacity in MBSL, demonstrating a clear temporal alignment between key metabolite accumulation and functional enhancement. This work decodes the scientific basis of its traditional value and establishes a robust foundation for its targeted optimization and development as a health-promoting functional beverage. © 2026 Society of Chemical Industry.