Protein quality evaluation of cowpea-based extrusion cooked cereal/legume weaning mixtures

The protein nutritional quality of cereal/legume mixtures developed with th eoretically optimal nutrient profiles was assessed by determining the indic es; Protein Efficiency Ratio (PER), Net Protein Ratio (NPR) and Protein Dig estibility Corrected Amino Acid Score (PDCAAS). Two formulations (generated by computer-assisted successive approximation) were prepared with 45-50% m aize, 35-40% cowpeas, and either peanuts or soybeans to improve the amino a cid balance and to raise the energy level of the diet. Isonitrogenous diets prepared from these weaning formulations and casein were fed to 21-28 day old Sprague Dawley rats according to the Official PER protocol. Acceptable PERs of 2.1-2.4 were obtained for the diets when casein was adjusted to 2.5 . The True Protein Digestibility of these food formulations ranged from 87. 4-92.1% (that of casein was 96.4%) and the NPR ranged from 3.0-3.3; NPR of the casein diet was 3.5. PDCAAS for the formulations ranged from 0.72-0.82. (C) 2001 Elsevier Science Inc. All rights reserved.