Optimization of the extrusion process for the production of ready-to-eat snack from rice, cassava and kersting's groundnut composite flours

- Snack was produced from rice, cassava and kersting's groundnut composite flours.
- Proximate and functional properties of composite flour were optimized.
- The optimum flour blends were extruded.
- Extrusion process conditions were optimized using response surface methodology.
- The extruded ready-to-eat snack was subjected to microbial analysis.

Ready-to-eat extruded snack made from optimized composite flour comprising rice, cassava and kersting's groundnut flours was produced. The experimental design for the statistical optimization of the composite flour was carried out using optimum mixture model of response surface methodology. The responses were the proximate and the functional properties. The variables were percentages rice, cassava and kersting's groundnut flours. Experimental design for the extrusion process was also carried out using central composite design of response surface methodology. The variables were moisture content, barrel temperature and screw speed while the responses were throughput, lateral expansion and residence time. The result showed that the optimum composite flour blends consisted 58 g/100 g, 33 g/100 g and 9 g/100 g of rice, cassava and kersting's groundnut flours respectively. The optimum composite flour consisted 21.88 g/100 g protein, 8.15 g/100 g fat, 15.5 g/100 g moisture, 0.75 g/100 g fibre content, 1.97 g/100 g ash, 51.77 g/100 g carbohydrate, 0.805 g/cm3 BD, 2.0 g/g WAC, 2.21 g/g OAC and 7.0 WSI. For the extrusion process, the optimum conditions were 20 g/100 g moisture content, 120 rpm screw speed and 97 °C. Microbiological analysis of the product showed that it is safe.