Vol. 12, Issue 3 (2023)

Author(s):
Suresh Bhise, Kaur A and Preeti Shukla

Abstract:
The effect of variation in extrusion conditions which includes feed moisture content (14-20%), screw speed (300-500 rpm), and barrel temperature (120-180 ºC) on the functional properties (water absorption index (WAI), and water solubility index (WSI), fat absorption capacity (FAC), foaming capacity (FC) and sensory properties (color, appearance, flavor, overall acceptability and textural characteristics) of an expanded soybean snack was investigated. Extruded snacks were prepared by substituting maize flour with developed texturized flour of soybean at 0-40% levels. Protein content increased to 14.64% in the snacks, thus prepared with 10% texturized soybean meal as compared to that of control i.e. 7.55%. Fibre content increased while protein digestibility improved with an increased level of incorporation of texturized defatted soybean flour. Increasing feed moisture content resulted in extrudates with lower expansion, lower WAI, higher WSI, higher hardness, and lower sensory acceptability. An increase in screw speed caused a slight reduction in density and hardness of soybean extrudate. The positive influence of feed moisture on screw speed was observed whereas barrel temperature exhibited a negative influence on WAI. The negative coefficient of linear terms moisture and screw speed indicated that WSI decreased with an increase in these variables. Between thus higher moisture content in the extrusion process which lowered WSI values could diminish protein denaturation.