Biochemical Evaluation of Protein Quality of Soybean-Fortified Traditional Weaning Foods in Kwara State

Protein-energy malnutrition during the weaning period remains a critical nutritional challenge in Kwara State, where traditional cereal-based weaning foods such as ogi and akamu provide insufficient protein for infant growth requirements. This study evaluates the protein quality of soybean-fortified versions of three traditional weaning foods, ogi, akamu, and pap, using biochemical indices of protein quality assessed in weaning rats as a surrogate model. Fortified weaning foods were prepared at 20 and 30 percent soybean replacement ratios and compared to unfortified controls and a commercial weaning food reference. Male weanling Wistar rats were fed the experimental diets for twenty-one days. Protein quality was assessed by protein efficiency ratio (PER), net protein retention (NPR), biological value calculated from nitrogen balance data, and net protein utilization. Amino acid scoring of each formulation was conducted by HPLC following acid hydrolysis. Results show that soybean fortification at 30 percent significantly improved PER, NPR, biological value, and net protein utilization compared to unfortified cereal controls. The 30 percent soybean-fortified ogi showed PER values (2.18) comparable to the commercial reference standard (2.31). Amino acid profiling confirmed that soybean fortification corrected the limiting amino acid profile of the cereal base, particularly improving lysine and threonine scores. No adverse effects were observed in any dietary group. These findings support the feasibility and nutritional effectiveness of soybean-fortified weaning food formulations for addressing protein malnutrition in infants in Kwara State. Keywords: protein quality, weaning foods, soybean fortification, protein efficiency ratio, Kwara State.