Vacuum-steam pulsed blanching enhances drying, nutrient retention, and anti-nutritional factor reduction in Vigna...

This study evaluates vacuum-steam pulsed blanching (VSPB) as a pretreatment for Vigna unguiculata pods, focusing on drying kinetics, nutritional quality, and anti-nutritional factors. Pods underwent 0-4 VSPB cycles, followed by hot air drying at 50, 60, and 70 °C. VSPB reduced peroxidase activity to 4.8 %, enhancing enzyme inactivation. Texture analysis revealed an 85.6 % reduction in hardness, while the Midilli model provided the best description of drying kinetics (R² ≥ 0.9979). Specific energy consumption decreased by up to 40 % at 70 °C for blanched samples. VSPB preserved ascorbic acid, vitamin A, and chlorophyll, reduced lignin by 29.63 %, and lowered lectins from 71.01 to 8.88 Hu/mg. Folate retention declined with increased cycles. SEM and TEM analyses revealed microstructural and ultrastructural disruptions enhancing moisture diffusivity. VSPB proves effective in reducing anti-nutritional factors and retaining nutrients, offering a promising pretreatment for Vigna unguiculata with potential industrial applications.