A rice grit-corn grit-chickpea flour blend was used as a model feed system for extrusion. Response surface methodology was used to study the effects of level of incorporation of cassava flour in feed composition (5-25%), feed moisture (12-16%), screw speed (1000-1400 rpm) and barrel temperature (80-120°C) by using a single screw extruder. Among the independent variables, feed moisture was found to be the most influential (p<0.05) to bulk density (BD), water solubility index (WSI) and water absorption index (WAI). Cassava flour level affected lateral expansion (LE) most significantly, however, temperature affected all the dependent variables equally at p<0.05, while screw speed altered significantly BD, WSI and WAI only.
Key words: Single screw extrusion, response surface methodology, rice and corn grit, chickpea flour, cassava flour.