Lactic acid bacteria fermentation drives metabolic remodeling to enhance anti-hyperuricemic potential and flavor quality of Portulaca oleracea juice

Fermentation by lactic acid bacteria (LAB) has been shown to boost health benefits and enhance flavor. This study investigated the impact of Limosilactobacillus fermentum HNU022, Pediococcus acidilactici HNU323 and Limosilactobacillus fermentum HNU054 fermentation on Portulaca oleracea juice (POJ). The result revealed fermentation boosted organic acids, antioxidant activities, and xanthine oxidase (XOD) inhibitory activity. The study using non-targeted metabolomics found 823 metabolites with differences, primarily concentrated in 5 pathways. Among them, isoflavonoid-related metabolites were upregulated, while purine metabolites were downregulated. The molecular docking results indicated that strong interactions between key metabolites and XOD‌. Electronic-tongue analysis showed improved flavor richness and reduced saltiness. In summary, lactic acid fermentation enhances the nutritional value, bioactivity, and flavor characteristics of POJ. Although molecular docking and in vitro activity assays indicate its antioxidant effects and XOD inhibitory capacity, these data still have certain limitations before in vivo activity studies are conducted for validation.