EFFECT OF EXTRUSION PARAMETERS ON THE PHYSICAL PROPERTIES OF CHICKPEA EXTRUDATES

Abstract

This study evaluated the effect of extrusion processing on the specific mechanical energy and physical properties of chickpea extrudates (expansion coefficient, bulk density and hardness). The experimental data were processed using the response surface methodology with the following parameters: temperature at the exit from the die (120-150 °C), humidity (20-24 %), and screw rotation speed (260-340 rpm). The factors that most influenced product performance were die outlet temperature and feed moisture content, and the interactions between them. A significant correlation was found between hardness and bulk density (positive), hardness and expansion coefficient (negative), and bulk density and expansion coefficient (negative). The desired characteristics (high expansion, low bulk density and hardness) for the chickpea were obtained at a high die outlet temperature, relatively high humidity and a high screw speed.