Effect Of Extrusion Condition And Defatted Soybean Inclusion On The Physico-Chemical, Invitro Digestibility And Sensory Acceptability Of African Breadfruit (Treculia Africana) Blends

Abstract

Effects of extrusion condition and defatted soybean inclusion on the physico-chemical, invitro starch and protein digestibility and sensory acceptability of African breadfruit blends were studied. The experiment had two levels of treatments: blends I and II. Blend I was composed of African breadfruit-undefatted soybean-corn flours; while blend II had African breadfruit-defatted soybean-corn flours. The two flour blends were brought to 21% moisture content by water addition through material balance and separately extruded at 1400C barrel temperature, 140rpm screw speed in a Brabender laboratory single screw extruder fitted with 2mm die nozzle diameter. Extrusion cooking condition and defatted soybean inclusion did not significantly (p>0.05) affect the iron and zinc contents of the extrudates. The molybdenum content was significantly (p<0.05) reduced; while the manganese content was significantly (p<0.05) increased on extrusion. Extrusion cooking condition significantly (p<0.05) increased the protein digestibility by 3.12% and 22.77% in extruded blends I and II respectively; while there was a reduction in invitro starch digestibility from 68.23 to 70.43% and from 56.27 to 72.86% in extruded blends I and II respectively. Extrusion cooking condition and defatted soybean inclusion did not significantly (p>0.05) affect the physical properties (extrudate temperature, flow rate, plug flow, extrudate diameter, deformation strength and expansion ratio) of the extrudates. Extrusion cooking condition and defatted soybean inclusion did not significantly (p>0.005) differentiate the acceptability of the two extrudates. Their general acceptability was rated the same.