Physio-Chemical and Sensory Properties of Protein-Fortified Extruded Breakfast Cereal/Snack Formulated to Combat Protein Malnutrition in Developing Countries

Protein malnutrition is prevalent in the developing parts of the world and children are the most affected. Millet, beans, and rice mixed with soymeal flour were processed to produce an extruded product using a single screw extruder. The Central Composite Design (CCD) of the Response Surface Methodology at varying temperatures (190-275°C) and screw speeds (60-110 rpm) was used to obtain best extrusion conditions to develop a protein-enriched extruded product with desirable physio-chemical and sensory properties. Sensory properties were evaluated in terms of color and overall visual acceptability of the extruded products using a nine-point hedonic scale. The results suggested that the two extrusion variables, barrel temperature and screw speed, influenced the extrudate physio-chemical and sensory properties. The fat absorption capacity and water solubility index were unaffected by the extrusion variables. The best extrusion condition was obtained at a screw speed of 60 rpm and a barrel temperature of 190°C based on expansion ratio, bulk density, water holding capacity, texture, color and overall visual acceptance of the extruded products. This study demonstrated that acceptable extruded products with higher protein content can be prepared from varying blends of millet, beans and rice flour under optimized extrusion conditions by incorporating up to 30% of soymeal flour. This is the first attempt to produce a soymeal-based protein enriched extruded product with millet and beans that can be included in a child’s meal as a breakfast cereal or a snack to fight protein malnutrition.