Evaluation of Amino Acid Profile and Protein Quality of Biscuits Produced from Wheat (Triticum aestivum) and Red Kidney Bean (Phaseolus vulgaris L) Flour Blends

This study was carried out to evaluate the amino acid profile and protein quality of biscuit produced from wheat (Triticum aestivum) and red kidney bean (Phaseolus vulgaris L) flour blends. The red kidney bean seed were sorted, cleaned, boiled, drained, oven dried, cracked, dehulled, milled, sieved to obtain the red kidney bean flour. The wheat flour was blended with red kidney bean flour in the ratio of 100:0 (sample A), 90:10 (sample B), 80:20 (sample C), 70:30 (sample D) and 60:40 (sample E) for wheat and red kidney beans respectively and use for the production of biscuits. Biscuits were analyzed for amino acid profile and the protein quality of the biscuits were also determined using standard methods. Casein diet (sample AA) and nitrogen free diet (sample F) where the positive and negative control for the protein quality study. A total of thirty-five (35) weaning albino rats were used for the study. The diets were subjected to amino acid profile and protein quality. The data obtained were subjected to statistical analysis. The results of the amino acid profile were glutamic, tyrosine, arginine, aspartic acid and lysine, had the values, 8.62 g/100g, 6.55 g/100g, 5.43 g/100g, 5.28 g/100g and 5.23 g/100g respectively. The result of the protein quality showed that about 98% of the nitrogen consumed by all the five groups of rats fed with the biscuit diets were absorbed and retained. The biological value ranged from 95.59±0.23 to 98.57±0.46%, the net protein utilization ranged from 90.91±0.17 to 95.04±0.65%, the true protein digestibility ranged from 49.43±6.89 to 86.04±3.04% and the protein efficiency ratio ranged from 1.38±0.31 to 2.54±0.62. Conclusively, this study showed that substituting biscuit with red kidney beans flour increased the amino acid profile and improved the protein quality of the biscuit. Keywords: Amino acid profile, Protein quality, Biscuit, Red kidney beans.