Effect of Processing on the Protein Quality of African Yambean and Bambara Groundnut Supplemented with Sorghum or Crayfish in Rats

Abstract

Forty-eight adult Wistar albino male rats (75-128 g) of age 8 weeks were used to study the effect of processing on the protein quality of African Yam Bean (AYB) and Bambara Groundnut (BG) supplemented with sorghum or crayfish. The rats were fed for 10 days. Three out of the ten days were adjustment and the rest for the balance period. Eight diets were formulated and fed to the rats. The mixed protein diets provided 10% protein daily for the entire study period. Casein (CA) was served as a reference protein. The N content of the food, urine and feces were analyzed using AOAC (1980) procedure. As judged by protein quality, rats fed the control diet had significant decreases (p<0.05) in all the parameters tested except for digested N (0.91 g) urinary N (0.11 g) and apparent digestibility (94.79%). Addition of an equal amount of Crayfish (CR) to sorghum (S) as a supplement decreased food intake, N intake and Nitrogen Balance (NB) in both Dehulled African Yam Bean (DAYB) and Soaked Brown Bambara Groundnut (SBBG). Dehulling of White Bambara Groundnut (DWGB) resulted to increases in all the parameters tested except for urinary N (0.05 g) and apparent digestibility (84.68%) as compared to the brown variety. Soaking of White Bambara Groundnut (SWBG) decreased protein quality in all the parameters tested as compared with the brown variety except for Biological Value (BV) (94.12%) and Net Protein Utilization (NPU) (76.92%). As judged by N intakes (1.24 g) digested N (1.05 g) and biological value (95.24%) the DWGB:S₁₈ diet appears to contain much more desirable pattern of Essential Amino Acid (EAA) than the other test diets. The result showed that it could be of great importance to people living in areas where these foods are staple.