Study of physicochemical stability of anthocyanin extracts from black peanut skin and their digestion enzyme and adipogenesis inhibitory activities

In this study, the physicochemical stability, and the digestive enzymes inhibitory potential of anthocyanins in black peanuts skins (BPS) were evaluated. Cyanidin-3-O-sophoroside (C3So) and cyanidin-3-O-sambubioside (C3Sa) were identified as the main anthocyanins in BPS. The anthocyanins extract showed a certain level of heat resistance. During the storage period (37 degrees C for 4 weeks), anthocyanins were stable and with a projected half-life of 66.59 days when the pH was 2.5. These results indicated that the anthocyanin from BPS presented higher thermal stability. Moreover, Anthocyanin-rich extracts could inhibit the main digestive enzymes, with the IC50 values were 185.1 mu g/ml (pancreatic lipase), 123.4 mu g/ml (alpha-amylase), and 82.75 mu g/ml (alpha-glucosidase), respectively. The in vitro cell study also indicated anthocyanins from back peanut skin showed a strong antiadipogenesis potential in 3T3-L1 cells by inhibiting the expression of the key adipogenic transcription factors and related genes. This research highlights the opportunity that black peanut skin could be considered as a promising resource of anthocyanins as a natural food colorant with multifunction properties.