Development of Groundnut Meal Incorporated Rice–Corn Flour Based Extruded Snack-Food

Abstract

Response surface methodology based at three levels and four factors central composite rotatable design was employed to develop groundnut meal (GM) incorporated extruded snack-food using twin screw extruder. The effect of GM incorporation (15–25%), moisture content of extruder feed (14–18%), screw speed (300–330 rpm) and barrel temperature (110–130 °C) on responses like expansion ratio (ER), breaking strength (BS), water solubility index (WSI) and overall acceptability (OAA) score of extrudates. A second-order polynomial model was used to study and explain the relationships between the responses and independent variables. GM content was found to be the most significant variable as it affected negatively ER and OAA (p < 0.01) while positively BS (p < 0.01) and WSI (p < 0.1). Moisture content significantly affected negatively on ER (p < 0.05), WSI (p < 0.01), OAA (p < 0.05) and positively on BS (p < 0.01). Screw speed significantly affected negatively ER (p < 0.05), OAA (p < 0.01) and positively BS (p < 0.05). Barrel temperature did not affect significantly on the responses within experimental levels. By employing graphical superimposition GM content of 20%, moisture content of 15%, screw speed of 309 rpm and barrel temperature of 130 °C were optimized. Extruded snack-food at optimized variables showed higher protein and fiber content as compared with control.