Optimisation of a Multi-Millet Ready-to-Eat Extruded Snack with Digestibility and Nutritional Perspective

A blend of flours of Finger millet, Pearl millet and Foxtail millet was attempted to get a nutritionally superior product. The in-vitro starch digestibility of the flours was studied and the blend of flours was used to develop an extruded ready-to-eat snack using response surface methodology. The aim was to achieve a product with optimum extrusion in terms of expansion ratio and a best flour blend to have better digestibility and the overall sensory acceptance of the product. The central composite rotatable design with flours of three millets (as independent variables) was studied with 20 design points against the three crucial responses namely, expansion ratio, digestibility and sensory acceptability of the extruded product. The quadratic models were best fit in case of digestibility and expansion ratio while for the sensory score linear model was found suitable. The equations obtained were validated for the predictability of responses. The proximate composition, mineral and fibre profile of the product revealed its nutritional strength. The product being a ready-to-eat snack has excellent potential for its commercialisation as the raw materials are not costly and are readily available locally.