Lactic fermentation enhances sensory quality and nutritional properties of fruit juice, though its comprehensive impact on sea buckthorn through Lactiplantibacillus plantarum fermentation (LPF) remains unreported. This study used volatolomics and metabolomics to explore mechanism of lactic fermentation improving flavor. LPF reduced total acidity (from 24.01 g/L to 15.79 g/L), increased total flavonoid by 20.35% and polysaccharide contents by 55.64%. It also increased the quantity of volatile compounds (from 36 to 41). β-Damascenone and ethyl isovalerate were key aroma compounds, while the increase of phenylethyl alcohol and phenylacetaldehyde improved sweet, fruity, and floral aroma. The rise of adenosine, hypoxanthine, and ornithine through purine metabolism pathways enhanced umami, the enlargement of pyridoxine, pyridoxamine, and tyramine through Vitamin B6 and tyrosine metabolism pathways increased richness, and the elevated glycyrrhizin, melezitose, and maltotetraose enhanced sweetness. This study provides insight into improving sea buckthorn flavor and direction to produce high quality products.

Keywords: Lactic fermentation; Metabolic pathways; Metabolomics; Sea buckthorn; Volatile compounds.