Influence of Extrusion Condition and Defatted Soybean Inclusion on the Functional and Pasting Characteristics of African Breadfruit (Treculia Africana) Flour Blend

Abstract

Influence of extrusion condition and defatted soybean inclusion on the functional and pasting characteristics of African breadfruit-Soybean-Corn flour blends was studied. The two blends were separately brought to 21% moisture content by water addition through material balance and extruded at 140⁰C barrel temperature, 140rpm screw speed in a single screw extruder fitted with 2mm die nozzle diameter. Functional properties such as bulk density, water absorption capacity, foam capacity and emulsion capacity increased from 0.61 to 0.75g/cm³, 2.19 to 2.88g_water/g_sample, 9.66 to 12.33% and 13.53 to 16.79% respectively with extrusion condition and defatted soybean inclusion. However, gelation capacity was decreased with defatted soybean inclusion. Extrusion condition and defatted soybean inclusion significantly (p<0.05) reduced the peak viscosity, trough, final viscosity and setback values of the extrudates. Extrusion condition and defatted soybean inclusion did not influence pasting time and temperature of the extrudates. The decreased viscosity values of the extrudates are an indication of their potential in infant food formulation.

Keywords: African breadfruit, Soybean, Corn, Extrusion cooking, Functional and pasting properties.