Impact of in Vitro Simulated Digestion and Fecal Fermentation on Stability, Antioxidant Capacity and Bioaccessibility of Phenolic Compounds from Lycium Barbarum L. VAR. Auranticarpum K. F. Ching

Abstract

Lycium barbarum L. var. auranticarpum K. F. Ching (also called yellow wolfberry) is an important wolfberry variety, but little is known concerning its phenolic profile and bioaccessibility during gastrointestinal digestion (GID) and colonic fermentation. In this study, phenolic extracts were prepared from the fruits of four varieties of yellow wolfberry and Huangguobian (HGB) showed the highest total phenolic/flavonoid contents and antioxidant capacity. Moreover, four representative phenolic monomers were identified in all samples though significant content variations existed. The bioaccessibility of phenolic compounds from HGB was investigated using a simulated digestion-fermentation model. After GID, the bioaccessibility of total phenolics increased by 11.18%, while that of total flavonoids decreased by 12.49%. Notably, the phenolic extracts remarkably modulated the microbial composition, elevated the concentration of total short-chain fatty acids (SCFAs) and lowered the pH value. This is the first study reporting the profile, antioxidant capacity and bioaccessibility of phenolic extracts from yellow wolfberry.

Keywords: Yellow wolfberry, phenolics, flavonoids, Gastrointestinal digestion, SCFAs, Gut microbiota