Melting Temperatures of Extruded Products with Texturized Proteins

Abstract

Thermal properties of new extruded products with texturized properties were examined using Differential Scanning Calorimetry (DSC). Corn-texturized protein systems were extrusion-cooked in a twin-screw extruder with varying feed rate (0.7-1.9 g/s), screw speed (150-250 rpm), extrusion temperature (150 to 260 degrees C), and feed moisture content (13 to 19 g/100g wet basis). Four different texturized legume flours, namely bean, chickpea, kidneybean, and lentil were mixed with corn grits. A simple mathematical model was used to correlate the melting transition temperature with the extrusion conditions and moisture content. As expected, phase transition behaviour and thermal properties of the corn-water-legume system depend significantly on product temperature, feed moisture and corn/legume ratio and less on screw speed and feed rate.