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.