Valorization of tropical fruit peel powders: Physicochemical composition, techno-functional properties, and in vitro antioxidant and antidiabetic activities

Abstract

This study aims to evaluate the physico-chemical composition, techno-functional properties and in vitro antioxidant and antidiabetic activities of papaya, pineapple and mango peels for their possible use as functional ingredients. The peel powders were found to possess interesting techno-functional properties, high dietary fiber content (37.77 to 62.26%) and phenolic compounds, namely gallic, ferulic, and p-coumaric acid, catechin, quercetin-3-β-d-glucoside and quercetin. They also showed excellent antioxidant activity, as determined by ABTS (3.63 to 29.8 µM TE/g), DPPH (5.76 to 35.3 µM TE/g), NO (60.67 to 86.35%) and O (17.56 to 50.64%). Mango peel powders presented the best ability to inhibit the activity of the different enzymes evaluated: modest α-amylase inhibition (51.40%), stronger α-glucosidase inhibitory activities (70.32%), and moderate antiglycation potential (57.15%). Peel powders of these tropical fruits make them suitable to be used as food ingredients with possible health benefits, improving intestinal function and controlling hyperglycemia. Further studies require animal models and, subsequently, in humans. Keywords: Bioactivities; Nutritional value; Peels; Techno-functional properties; Tropical fruits