Protein quality of dehulled-defatted African mesquite bean (Prosopis africana) flour and protein isolates

Abstract

In this study, the protein quality of dehulled-defatted African mesquite bean (Prosopis africana) flour and protein isolates obtained using micellization and isoelectric precipitation methods were investigated. The dominant amino acids in the dehulled-defatted Prosopis africana flour and protein isolates included aspartic acid, glutamic acid, leucine and arginine, while the first, second and third limiting amino acids were methionine, threonine and valine/tryptophan, respectively. Amino acid profiles and scores, classifications and ratios, predicted protein efficiency ratios (1.79–2.89), biological (12.61–37.97%) and net protein (15.77–50.84%) values, essential amino acid (63.94–87.02%) and nutritional (23.33–70.78%) indexes showed that the dehulled-defatted P. africana flour and its protein isolates were of high protein quality and could be employed in complementing cereal-based and other similar foods whose proteins are deficient in lysine. Isoelectric precipitation method yielded protein with better nutritional quality compared to the micellization method. P. africana flour and protein isolates could therefore be exploited as protein sources in food formulation for tackling protein malnutrition in Africa.