Nutrient and antinutrient composition of extruded acha/Soybean blends

The nutrient and antinutrient composition of raw and extruded blends of acha and soybean was evaluated. Acha and soybean grains were cleaned and milled into flour separately and sieved to pass 0.75-1.00 mm mesh. The moisture content of the flours was determined. Soybean flour was added to acha flour at 25% levels of substitution. The moisture content of the blends was adjusted to 25% levels. The blend was extruded using a Brabender laboratory single-screw extruder (Duisburg DCE-330 model, Duisburg, Germany). Amino acid profile, proximate composition, minerals and some water-soluble vitamins of raw and extrudate samples were determined. The oxalate, saponin, tannin, and phenol, content of raw and extrudate samples were also quantified. The results showed that the amino acids of the raw blend were higher (14.00-50.38 %) than either of the sole flours. Extrusion cooking resulted in the depletion of some amino acids between 2.96 and 40%, with methionine and phenylalanine recording the highest and least losses. As expected, fat content of the blend increased from 2.8 to 8.33% alongside the protein (7.05-14.28%). Extrusion cooking did not have significant (P ≤ 0.05) effect on these parameters. The results for mineral content showed that extrudate zinc, magnesium and chromium content decreased but not significantly (P ≥ 0.05), while iron, nickel, selenium and sodium increased significantly (P ≤ 0.05). Blending acha and soybean raised the water-soluble vitamins content of the feed when compared with the levels of the vitamins in raw acha flour. Extrusion cooking significantly (P ≤ 0.05) decreased these minerals. Blending acha flour and soybean flour at 25% level of soybean flour substitution resulted in dilution of all the antinutrients evaluated. Extrusion cooking further lowered these nutrients with saponin being totally eliminated. © 2010 Wiley Periodicals, Inc.