Abstract:Objective This study aimed to investigate the effects of Lactobacillus plantarum (L. plantarum) fermentation on the metabolism of flavonoids and organic acids in mango juice.Method Six strains of L. plantarum were selected for fermentation of the juice samples from two mango varieties ‘Tainong' and ‘Guiqi'. The mass concentrations of organic acids and flavonoids in the juice samples were determined by ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Orthogonal partial least squares discriminant analysis was employed to compare the metabolites in the mango juice samples fermented with different strains.Result L. plantarum fermentation significantly enhanced the total antioxidant capacity (T-AOC) of mango juice. Furthermore, the composition of organic acids changed significantly, with a significant increase in the mass concentration of lactic acid and decreases of over 99% in the mass concentration of malic acid and over 10% in the mass concentration of citric acid. In addition, a total of 142 flavonoids were detected in both unfermented mango juice and fermented mango juice, with 42 significantly differential metabolites identified after fermentation. The KEGG pathway enrichment analysis of differential metabolites showed that L. plantarum fermentation promoted the enrichment of products related to flavonoid biosynthesis and anthocyanin biosynthesis pathways. Compared with unfermented juice, the fermented juice samples of both mango varieties showed significantly increased mass concentrations of phlorizin, 3,4,2',4',6'-pentahydroxychalcone, apigenin, cyanidin-3,5-O-diglucoside, and pelargonidin-3-O-glucoside and significantly decreased mass concentrations of eriodictyol, luteolin, pinocembrin, pinobanksin, phloretin, quercetin, and 3,4,2',4',6'-pentahydroxychalcone-4'-O-glucoside.Conclusion L. plantarum fermentation significantly affects the levels of organic acids, anthocyanins, and flavonoids in mango juice, enhancing the mass concentrations of bioactive components in fermented mango juice.
