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.