Evaluation of pomegranate (Punica granatum) peel for bioaccessibility of polyphenols and prebiotic potential using in vitro model

Abstract

This research evaluated the bioaccessibility of polyphenols and prebiotic potential of pomegranate peel powder (PPP) on an in vitro model of static gastrointestinal digestion (IVD) combined with a colonic fermentation assay using L. acidophilus. After the IVD, the TPC, TFC, FRAP, DPPH-RSA, and ABTS-RSA were significantly different (p ≤ 0.05) at each digestion phase. Furthermore, the recovery of TPC and TFC after intestinal digestion was profoundly affected (p ≤ 0.05) by salivary or gastric digestion phases by 52.47 and 20.34%, correspondingly. The bioaccessibility values were 34.40 and 30.35%, respectively. Residual intestinal digestibility index (RID) values were 34.36 and 14.16%, respectively. There was a strong correlation (between polyphenolic compounds and antioxidant capacity at each digestion phase. PPP is revealed to be an excellent source of microbial substrates at the level of the large intestine; hence, it is a potential prebiotic. Moreover, PPP is an excellent source of fiber and has high functional properties; thus, it might be utilized in the food industry as a functional ingredient or as a nutraceutical that promotes health.

Keywords

• In vitro digestion
• Bioaccessibility index
• Prebiotic
• Fruit peel
• Antioxidants