Chemical composition, amino acid profile, anti nutritional factors (ANFs) and protein quality factors of different thermally (extrusion, cooking, toasting and roasting) processed soybeans (Glycine max) for broiler diets were evaluated in this study. Dry Matter (DM) percentage ranged from 79.00 to 91.25% while Crude Protein (CP) percentage ranged from 12.51 to 28.34%. Crude Fibre (CF) values were highest with toasting (28.34) while cooking gave the lowest value (12.51). Ether Extract (EE) highest value was obtained in cooked soybeans (19.50%) while the least (9.72%) was obtained in extruded soybeans. Total ash percentages ranged from 4.27 to 4.46% while NFE percentage ranged from 13.75 to 26.31%. Ca and P percentage values were high (1.08 and 0.33%) in roasted and extruded respectively. Amino acid profiles (g/100 g protein) values for lysine ranged from 2.40 to 5.1, while cystine had values ranging from 0.64 to 0.88. Methionine value were highest (1.02 and 1.14) in cooking and roasting and least in extrusion (0.52) while phyenylalanine values ranged from 3.06 to 4.26. Reduction due to treatment was observed in Trypsin Inhibitor Activity (TIA) and phytic acid and cooking methods was highest for TIA (85%), extruded soybeans (60.59%), toasted and roasted soybeans were similar (52.44% and 53.75%). Reduction in phytic acid was highest with roasted soybean (71.7%), followed by 70.73% in cooked soybeans, toasted soybean was least (48.12%). Urease assay values ranged from 0.02 to 0.09 (ΔpH) and cooked soybean had highest protein solubility index of 83.40%. Phytic acid and Trypsin Inhibitor Activity (TIA), phytic acid and percentage reduction in TIA, Protein Solubility Index (PSI) and phytic acid, TIA and percentage reduction in TIA were correlated. Protein quality and TIA inactivation was more preserved and effective with cooking method.
M.M. Ari, B.A. Ayanwale, T.Z. Adama and E.A. Olatunji, 2012. Evaluation of the Chemical Composition and Anti Nutritional Factors (ANFs) Levels of Different Thermally Processed Soybeans. Asian Journal of Agricultural Research, 6: 91-98.