Process Optimization for Development of Extruded Snack from Brown Rice-Amaranth-Moringa Seed Powder Blend

The study was aimed at utilizing brown rice, germinated amaranth and moringa seed powder in the development of nutritious extruded product. The extruded product was optimized by employing Response Surface Methodology using Central Composite Rotatable Design (CCRD). The experiment consists of three independent variables each having five different levels. The process variables were selected as feed moisture content (8-16%), blend ratio of brown rice flour: germinated amaranth flour: defatted moringa seed powder (50:45:5, 50:40:10, 50:35:15, 50:30:20 and 50:25:25) and barrel temperature (100-140ºC). Optimization was done on the basis of product responses i.e. bulk density, expansion ratio and hardness. The values of bulk density, expansion ratio and hardness of extruded products ranged between 0.06 to 0.35 g/cm2, 2.30 to 3.34 and 497.48 to 1425.17 g, respectively. The optimum values of extrusion conditions obtained through numerical optimization were blend ratio (50:30:20), feed moisture content (12%) and barrel temperature (1300C). The corresponding predicted values for bulk density, expansion ratio and hardness was 0.0964 g/cm3, 3.33 and 617.16 g, respectively with desirability 0.912. Whereas the corresponding experimental values for bulk density, expansion ratio and hardness were 0.0939 g/cm3, 3.35 and 635.56 g, respectively. Thus, it is concluded that the brown rice, germinated amaranth and defatted moringa seed has potential to be incorporated in the development of nutritious extruded snacks.