No abstract

Paired feeding studies with rats have shown that the increased protein efficiency ratio resulting from the addition of 20% water to a 9% protein purified diet was not due to increased protein consumption. It was shown further that when sucrose was the source of carbohydrate, increments of water addition of from 5 to 35% resulted in increases in the protein efficiency ratio of casein. Furthermore when cornstarch or dextrin was used as the carbohydrate source an increased PER was not obtained with casein when 20% water was added, but was observed when 50% water was added. The effect of adding 20% water to a dry purified diet containing sucrose as the carbohydrate was also observed when isolated soybean protein, cottonseed protein or enriched white flour was used as the source of protein.