Assessment of protein nutritional quality and effects of traditional processes: A comparison between Ethiopian quality protein maize and five Ethiopian adapted normal maize cultivars

The present study was designed to quantitatively measure and compare the levels and variations of total protein, individual amino acids, and computed protein efficiency ratio (C-PER) in raw and traditionally processed products of one recently released quality protein maize (QPM BH542) with four high-yield maize hybrids, namely flint BH660, semi-dent BH140, Pioneer 30H83, and Pioneer 30697, as well as one local maize cultivar. The total protein content was variable among the cultivars ranging from 7% for BH660 to 8.6% for Pioneer 30H83, 8.9% for BH140, 9.8% for QPM BH542, 10.1% for local maize cultivar, and 11.8% for Pioneer 30697, respectively. However, the QPM BH542 maize protein proved to be higher in nutritional quality than common maize proteins because it contained 30% to 82% more lysine, higher levels of arginine, tryptophan, histidine, threonine, cysteine, and valine. As a result, the QPM BH542 amino acid profile gives a good balance of total essential amino acids, limited only in lysine, and has a C-PER ratio of 2.2 compared to 1.14, 1.2, 1.4, 1.66, and 1.67 for Pioneer 30697, local, BH-140, BH660, and Pioneer 30H83, respectively. The various traditional processes of maize have no significant effect on the protein nutritional quality of the new quality protein maize. Hence, the widely dissemination of it in agricultural cultivation as well as consumption by the general population is recommended.