Antioxidant potential of microencapsulated bioactive extracts from durian fruit’s pulp, seed, and peel as food additives

Background Durian pulp consumption is growing rapidly worldwide, but so is the waste it generates: seeds and peels. This study investigates the Total Phenolic Content (TPC) and antioxidant activity of extracts and microencapsulated extracts from the main components of the durian fruit: seed (Dse), pulp (Dpu), and peel (Dpe). Methods The TPC was evaluated by the Folin-Ciocalteu method, and the antioxidant activity was measured using the DPPH, FRAP, and ABTS methods. The phenolic compounds profile was obtained by UPLC-MS/MS. Microencapsulation of durian extracts was achieved by spray drying using gum arabic and polydextrose as encapsulating agents. A Differential Scanning Calorimeter analyzed the thermostability of microcapsules, while the bioaccessibility of phenolic compounds was measured using an in vitro digestion test. Results The seed extracts (18 mg GAE/g DW) showed higher TPC than pulp and peel extracts (1.7 and 6.5 mg GAE/ g DW, respectively). The seed extracts showed the highest antioxidant capacity across all assays (DPPH: 9.9, FRAP: 9.7, ABTS: 9.8 mg TE/g DW) and were strongly correlated with TPC (r = 0.73–0.91, p < 0.001). UPLC results showed that flavonoids (52%) are the predominant polyphenols, followed by phenolic acids (25%), lignans and coumarins (16%), and tannins (6%). Microencapsulation of durian extracts was achieved by spray drying under the optimal conditions of 53.1% gum arabic and 46.9% polydextrose, determined through an experimental design. The microcapsules of the Dse, Dpu, and Dpe extracts were thermostable, whereas the free extracts showed degradation over the temperature range from −4 to 200 °C. The in vitro digestion test showed 69.8–99.7% bioaccessibility of phenolic compounds across the oral, gastric, and intestinal phases, depending on the fruit component, where Dse microcapsules exhibited the highest bioaccessibility. Conclusion The results of this study demonstrate the promising potential of valorizing bioactive compounds from durian fruit and its waste through extraction and microencapsulation for food and pharmaceutical applications.