Characterization of metabolites of elderberry juice fermented by Lactobacillus bulgaricus BNCC336436 and Streptococcus thermophilus ABT-T using LC–MS/MS

Elderberry fruits are rich in nutrients and health-promoting bioactive compounds, meaning they are ideal substrate for lactic acid bacteria (LAB) fermentation. However, there is a lack of study on the compounds change of elderberry juice (EJ) fermented by LAB. This research used untargeted metabolomics to evaluate the changes of metabolites of EJ after fermented by Lactobacillus bulgaricus BNCC336436 and Streptococcus thermophilus ABT-T. Multivariate statistical analysis was applied to investigate significantly different between the unfermented and fermented EJ ( p < 0.05). Subsequently, 86 marker metabolites were identified by LC–MS/MS. The results showed that 16 phenolic compounds, 15 amino acids and derivatives, 11 sugars and derivatives, 10 fatty acids and derivatives, 6 organic acids and 28 other compounds were identified as marker metabolites between unfermented and fermented EJ. The content of total phenolic, total amino acids and derivatives tented to increase after fermentation, whereas the content of sucrose, l -fucose, l -malic acid, tartaric acid and citric acid decreased. The bioactive compounds of EJ were changed after lactic acid bacteria (LAB) fermentation, which provided a new choice for the development and utilization of EJ in the future.