The study of functional properties of kiwifruit peel dietary fiber and the bioactivity as well as synergetic prebiotic effects of bound phenolics in it during in vitro gastrointestinal digestion and colonic fermentation.

The structure, functional performance of soluble and insoluble Kiwifruit (Actinidia chinensis Planch) peel dietary fiber (KPDF) as well as abundant bound phenolics (BPs) in them were systematically investigated. It turned out that KPDF conserved outstanding capacities in adsorption and cation exchange. 23 BPs were identified in KPDF, most of which were inaccessible during in vitro gastrointestinal digestion but up to 27.10 % and 57.89 % BPs were released form insoluble and soluble KPDF after 24 h and 12 h colonic fermentation, respectively. Meanwhile, KPDF promoted the reproduction of beneficial bacteria such as Prevotella, Dialister, Faecalibacterium, while reducing the abundances of harmful bacteria such as Collinsella, Dorea, and Gemmiger with BPs contributing to such features. Such results reflected the promoting effects of BPs in the prebiotic effects of functional KPDF, providing theoretical foundation for the further exploration of KPDF as functional nutritional factors in health promotion.