Exploring the polyphenolic profile and antioxidant potential of three durian ( <i>Durio zibethinus</i> M.) cultivars

Abstract Durian (Durio zibethinus Murr.) is a tropical fruit valued for its rich nutritional composition and distinctive aroma. The increasing demand for durian pulp has resulted in a steady increase in production; however, this expansion has led to generation of large quantities of non-edible by-products. Increasing amounts of peel and seed waste have prompted interest in their possible conversion into value-added products. This study aimed to compare the antioxidant capacity and the polyphenolic profile from four different parts (peel, endocarp, pulp, and seed) across three durian cultivars. Our results demonstrated that total phenolic content (TPC) ranged from 0.63 to 32.81 mg gallic acid equivalent/g on a dry weight (DW) basis, with the greatest values in seed samples and the lowest in pulps. Total flavonoid content followed the same pattern as TPC and ranged from 0.16 to 0.91 mg quercetin equivalent/g DW. We further confirmed the high correlation between phenolic content and antioxidant potential in all durian parts, suggesting polyphenols might be the major contributor to their antioxidant capacity. We tentatively identified 51 phenolic compounds through liquid chromatography-electrospray ionization (ESI)-quadrupole time-of-flight mass spectrometry analysis, with phenolic acid and flavonoids being major compounds identified in durian. Five polyphenolic compounds were quantified, including epicatechin (0.157–0.946 mg/g), catechin hydrate (0.309 mg/g), epigallocatechin (0.468 mg/g), 3,4-dihydroxyhydrocinnamic acid (0.084 mg/g), and 4-hydroxybenzoic acid (0.036 mg/g) through high-performance liquid chromatography coupled with diode array detection.