Revealing the variation in activities and material basis of Camellia fascicularis polyphenols during in vitro simulated digestion using widely targeted metabolomics

Camellia fascicularis is widely used as a tea beverage and is famous for its high polyphenol content. However, changes in the activities and material basis of Camellia fascicularis polyphenols (CFP) during digestion are still unknown, limiting the application of CFP in food industry. In this study, the composition and changes in the antioxidant and anti-lipid peroxidation activities of CFP at different digestion stages were investigated using in vitro simulated digestion and metabolomics. The results showed that the total phenolic content of CFP decreased significantly after intestinal digestion, yet maintaining elevated antioxidant levels and anti-lipid peroxidation capabilities, and managing to attenuate oxidative stress-induced cellular damage. Additionally, metabolomics analyses revealed that 13 significantly differential metabolites as the main contributors were characterized to be positively correlated with biological activities during the in vitro simulated CFP digestion. This work offers theoretical bases for developing CFP functional foods or nutritional supplements with multiple potential bioactivities. • Changes in Camellia fascicularis polyphenols (CFP) and activities during digestion. • CFP and its intestinal metabolites showed ameliorative effect on oxidative stress. • A total of 830 phenolic compounds were recognized before and after CFP digestion. • Thirteen notably differential metabolites were positively related to bioactivity.