Serum amino acid concentrations in growing rats fed intact protein versus enzymatic protein hydrolysate-based diets.

The aim of this study was to evaluate the effect of the molecular form of dietary protein (native or enzymatically hydrolyzed) on the total serum protein concentrations and the serum amino acid profile of growing rats at weaning. Wistar male rats at weaning were randomly assigned to one of the four isocaloric and isonitrogenous (12% protein equivalent content) diets and fed for 7 days. The protein sources of the diets were: whey protein, casein and their respective hydrolysates. Differences in the serum amino acid profiles exclusively related to the amino acid composition of the protein (casein or whey proteins) were observed, but differences due to their molecular form were not observed. It is concluded that the use of enzymatic hydrolysates of whey proteins and casein has the same effects as their native proteins on nitrogen intake, body weight gain and serum amino acid profile of growing rats at weaning.