Phytochemical profile, bioactivity and prebiotic potential of bound polyphenols released from Rosa roxburghii fruit pomace dietary fiber during in vitro digestion and fermentation.

Abstract

The aim of this study was to elucidate the liberation and phytochemical profile of bound polyphenols present in dietary fiber (RPDF) isolated from Rosa roxburghii fruit pomace during in vitro-simulated digestion and colonic fermentation. The variation in the biological activity and prebiotic potential of the released polyphenols from RPDF was investigated. The results showed that the bound polyphenols were released from RPDF at a higher ratio during colonic fermentation than gastrointestinal digestion. The released polyphenols showed antioxidant activity and α-glucosidase inhibitory activity. The in vitro colonic fermentation assay showed that compared with dephenolized RPDF (DP-RPDF), RPDF exhibited a significantly stronger prebiotic effect by lowering the Firmicutes to Bacteroidetes (F/B) ratio at the phylum level, increasing the relative abundances of beneficial bacteria at the genus level, and improving the production of short chain fatty acids (SCFAs). These findings indicate that the bound polyphenols may act as important functional food ingredients that can contribute to the biological properties of RPDF. In addition, this study provides new insights into the high-value utilization of Rosa roxburghii fruit pomace, which will reduce the wastage of resources and greatly contribute to environmental protection.