Effect of Autoclaving on Nutrients, Phenolics, Antioxidants, and Enzyme Inhibitory Properties of Dioclea reflexa Seed Flours

This study examined the impact of autoclaving on the nutritional, phytochemical, phenolic, antioxidant, and enzyme inhibitory properties of three varieties of Dioclea reflexa seed flours: light brown (LB), dark brown (DB), and black (B). Each variety was evaluated in raw form and after autoclaving for 10 and 30 min. Autoclaving led to a reduction in protein content, with the light brown variety maintaining the highest levels (24.94 to 21.44 g/100 g). Significant decreases in phytates (87.2%) and trypsin inhibitors (69.4%) were observed, especially in the light brown variety. Autoclaving significantly enhanced total phenolic content, particularly in the black variety, which showed the highest increases in catechin, quercetin, and chlorogenic acid. However, these increases were not accompanied by proportional improvements in antioxidant activity, indicating alterations in phenolic functionality. The light brown variety retained the highest antioxidant capacity based on the metal chelation assays. Enzyme inhibition studies revealed that autoclaving markedly improved α-amylase and α-glucosidase inhibitory activities, with the light brown variety showing the highest inhibition after 30 min (86.98% and 68.31%, respectively). These findings support the potential of autoclaved D. reflexa flours, especially the light brown and black varieties, as functional food ingredients for glycemic control.