Effects of Pomelo Peel-Derived Dietary Fibers on Simulated Intestinal Digestion and Fermentation of Fish Balls In Vitro

Abstract

The effects of pomelo peel-derived dietary fibers (total dietary fiber, cellulose, and microcrystalline cellulose) on in vitro simulated gastrointestinal digestion and fermentation characteristics of silver carp fish balls were systematically investigated. Our findings revealed that pomelo peel dietary fibers significantly enhanced protein digestibility (highest increased by 18.58%), free amino acid content (most elevated by 13.27%), and slow digestion starch content (highest increased by 64.97%) in fish balls, suggesting an improved nutritional quality of fish balls. Moreover, pomelo peel-derived dietary fibers increased the content of short-chain fatty acids in the digestive fish balls at the late stage of fermentation (48 h) and caused changes in gut microbiota with reducing the ratio of Firmicutes to Bacteroidetes (F/B), the abundance of Escherichia-Shigella and Streptococcus, and increasing the levels of probiotics Bacteroides and Phascolarctobacterium. These suggested that pomelo peel-derived dietary fibers could promote the digestive characteristics of fish balls, effectively exerting prebiotic effects by regulating gut microbiota. The results could provide a scientific basis for the enhanced modification of intestinal digestion and fermentation of fish balls with dietary fibers.