Response surface analysis and process optimization of non-cereal (elephant foot yam, taro and water chestnut) snacks

The present study was conducted to develop non-cereal starch extruded products. The effects of feed moisture (15-21%), temperature (130-170 °C) and screw speed (120-160 rpm) were evaluated on the physical and functional properties of extruded snacks using response surface methodology. Feed moisture and screw speed increased the bulk density and hardness of extruded snacks. Significant decreases in water absorption index and increases in water solubility index were observed with increases in extrusion temperature. The best conditions were determined by numerical optimization. The optimized value for non-cereal snacks for feed moisture is 18.22%, temperature 155.96 °C, screw speed 142.75 rpm and, desirability is 0.75. Verification of results showed decent agreement between the responses of experimental values at certain optimum conditions and the predicted values