SUPPLEMENTARY EFFECT OF EGG-WHITE PROTEIN ON THE UTILIZATION OF SOY PROTEIN ISOLATE IN GROWING RATS

Although the effectiveness of the replacement of soy protein with egg white protein is widely accepted, much is unknown about the relationship between the replacement ratio and the quality improvement of mixed protein. Therefore in this experiment, we studied the relationship in rats fed 10% protein diet by weight for 21 days. The dietary proteins were soy protein isolate, egg white protein, casein, and 30, 50 and 70% replacement of soy protein isolate by egg white protein. The results of food intake, body weight gain, nitrogen balance, carcass protein, plasma aminogram, biological value, net protein utilization and protein efficiency ratio showed that the quality of soy protein was improved as compared to that of egg white protein and casein by the replacement of 70% and 30-50%, respectively.