Metabolic variation in sea buckthorn berries during yearly natural fermentation via non-targeted metabolomics

This study used UPLC-MS-based non-targeted metabolomics to explore the metabolic changes and identify potential targets in yearly fermented sea buckthorn berries from Mount Wutai over 1–4 years of natural fermentation. A total of 520 metabolites were identified, including 241 core differential metabolites and 311 feature-important metabolites during fermentation based on traditional analysis supplemented by random forest algorithm. Pathway enrichment analysis revealed that the annotated core differential metabolites were predominantly enriched in flavone and flavonol biosynthesis, phenylalanine, tyrosine, and tryptophan biosynthesis, as well as phenylalanine metabolism. Important metabolic pathways network analysis suggested that astragalin, phenylalanine, and pyruvate may serve as potential targets for investigating variations in the flavonoid and flavonol biosynthesis pathways, as well as amino acid biosynthesis. Further studies are warranted to validate these targets in controlled fermentation systems. Thus, these findings provide comprehensive insights into the variation of bioactive components and time-dependent effects in sea buckthorn berries during 1–4 years of natural fermentation and offer potential strategic guidance for the targeted development of sea buckthorn berry-based functional products. • A total of 520 metabolites were identified during the yearly natural fermentation of sea buckthorn berries from Mount Wutai through UPLC-MS-based non-targeted metabolomics. • Traditional analysis, supplemented by random forest algorithm, revealed 241 core differential metabolites and 311 feature-important metabolites during fermentation. • The 241 core differential metabolites were enriched in 145 KEGG pathways, with 20 significantly altered (P < 0.05), primarily including flavone and flavonol biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis, as well as phenylalanine metabolism. • Astragalin, phenylalanine and pyruvate are proposed as be potential targets for further investigation of variations in relevant pathways.