Assessment of Some Anti-Nutritional Factors in Extruded Soybean and Aerial Yam Flour Blend

Abstract

This study assesses the levels of some anti-nutritional factors (ANFs) in extrudates produced from the blend of soybean and aerial yam flours. The soybean and aerial yam flours were blended in a ratio of 3:1 (75% soybean flour, 25% aerial yam flour). The blended soybean and aerial yam flours were then extruded using a laboratory scale single-screw extruder at 33% feed moisture content; 110  barrel temperature and 130 rpm screw speed. The results of the laboratory analysis of the extrudates show that the levels of anti-nutritional factors were 73.80 mg/100g of sample for oxalates; 1.81 mg/100g of sample for tannin; 25.39 mg/100g of sample for phytate; 2.22 mg/100g of sample for hydrogen cyanide (HCN); and 1.64% for alkaloids. This study has shown that the levels of the anti-nutritional factors in the extrudates produced from soybean and aerial yam flours blend are minimal, and are below the FAO/WHO recommended safe level of toxicity to humans, and these anti-nutritional factors can be reduced to the level of non-toxicity, through extrusion processing technology.