Comparison of the protein nutritional value of food blends based on sorghum, bambara groundnut and sweet potatoes.

The protein quality of four blends based on sprouted sorghum, bambara groundnuts and fermented sweet potatoes had been evaluated by rat feeding experiments; casein served as a reference protein. The test proteins were incorporated to make up 1.6% total nitrogen. There was an inverse relationship between % nitrogen disgestibility and the proportion of sorghum protein in the blend; being highest (89.7%) in the diets based on sorghum:bambara groundnut:sweet potatoes with protein ratios of 52:46:2. This blend proved to be optimum when the biological value (93.6%) and the net protein utilization (84%) were used as protein indices. The findings imply that foods with good protein quality could be formulated from a blend of sorghum-bambara groundnut and sweet potatoes, provided appropriate processing and blending are taken into consideration.