Impact of Different Drying Techniques on Parkia timoriana Pods: Physicochemical, Nutritional, and Bioactive Insights...

Parkia timoriana (Yongchak) is a nutrient-rich, underutilized tree bean widely consumed in northeast India and used traditionally against various ailments. In this study, the different parts of P. timoriana pods (outer pulp [OP], seeds, and whole pods) were processed through four different drying techniques: sun-, oven-, microwave-, and freeze-drying. Further, the study aimed to evaluate the effect of these drying techniques on the physicochemical and nutritional properties of P. timoriana pods, along with the antioxidant and antidiabetic potential of their extracts. In addition, a computational approach, incorporating molecular docking and molecular dynamics simulation, was conducted on 42 previously reported bioactive compounds of P. timoriana pods against α-amylase as target protein, with acarbose as reference. The findings indicated that the seeds of P. timoriana showed the highest protein (31.73 mg/100 g dry weight [DW]) and fat (21.48 mg/100 g DW) contents, whereas carbohydrate (42.59 mg/100 g DW), crude fiber (22.40 mg/100 g DW), and ash (10.40 mg/100 g DW) contents were highest in OP. Moreover, highest phenolic contents (47.68 mg GAE/g), with stronger 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging (IC₅₀: 19.12 µg/mL) and α-amylase inhibitory (IC₅₀: 319.55 µg/mL) activities, were observed in OP extracts. Among the drying methods, sun- and freeze-drying provided higher yield, better rehydration, physical stability, enhanced antioxidant properties, and α-amylase inhibition. All the dehydration methods showed good retention of all the minerals. Further, molecular docking and MD simulation determined stigmasterol (-9.5 kcal/mol) as the potential inhibitor against α-amylase. This study can be helpful in the future utilization of the pods as food additives and as dietary supplements for managing diabetes. PRACTICAL APPLICATION: This study validated the nutritional, physicochemical, and antidiabetic properties of Parkia timoriana pods through in vitro and in silico approaches. These pods can be helpful in the future utilization in functional food development as nutrient-rich food additives and dietary supplements for managing diabetes. This study also concluded that sun- and freeze-drying techniques proved to be commercially beneficial in increasing the shelf life and preserving the nutritional quality of P. timorina pods.