Investigation of process and product parameters for physicochemical properties of rice and mung bean (Vigna radiata) flour based extruded snacks.

PR 106 and SML 668 cultivars of rice and mung bean respectively, were studied for their potential to serve as a nutritious snack with improved protein quality and quantity. The effect of extrusion conditions, including feed moisture content (14-18%), screw speed (400-550 rpm) and barrel temperature (130-170°C) on the physicochemical properties (bulk density, water absorption index (WAI), water solubility index (WSI) and hardness) was investigated. The replacement of rice flour at 30% level with mung bean flour for making extruded snacks was evaluated. Pasting temperature increased (84-93 °C) while peak viscosity (2768-408 cP), hold viscosity (2018-369 cP), breakdown (750-39 cP), setback (2697-622 cP) and final viscosity (4715-991 cP) decreased with increasing mung bean flour addition. Increasing feed moisture lowered the specific mechanical energy (SME), WAI and WSI of extrudates whereas increased bulk density and hardness. Higher screw speed had linear positive effect on SME of extruder and negative linear effect on WAI. Positive curvilinear quadratic effect of screw speed was also observed on WSI and density. Higher barrel temperature linearly decreased the SME, density and hardness of extrudates. Developed extrusion cooked rice-mung bean snacks with increased protein content and improved protein quality along with higher dietary fibre and minerals have good potential in effectively delivering the nutrition to the population.