Effect of extrusion processing on the physical properties of protein rich snacks containing soybean (glycine max)

Abstract

Extrusion cooking is a modern high-temperature short-time (HTST) processing technology which is becoming popular in certain industries because it offers several advantages over other types of cooking processes. This study aimed to evaluate the effect of the extrusion barrel temperature (90, 120 and 150oC), feed moisture content (10, 15, and 20%) and feed ratio (0, 15 and 30% Soybean) on the expansion ratio (ER), water absorption index (WAI), water solubility index (WSI), colour and hardness of the extruded snacks keeping other extrusion conditions constant such as feed rate and screw configuration. The results showed that the extrusion processing conditions and soybean ratio in the mixture had significant effects on the physical properties of the snacks. Under conditions of low feed moisture (10%) and low barrel temperature (90oC) and 30% Soybean snacks with desirable physical properties can be obtained.