NUTRITIONAL AND ANTIGENIC CHARACTERIZATION OF AN ENZYMATIC WHEY-PROTEIN HYDROLYSATE

The present work was mainly undertaken to describe a method of charact erizing protein hydrolysates suitable for use in enteral formulas. A c ommercial enzymatic whey protein hydrolysate was studied. Its chemical composition, molecular weight distribution, nutritional qualities (as sessed by the measurement of the digestive and metabolic nitrogen util ization in growing rats), and potential antigenicity (by in vitro and in vivo tests) were determined. The large majority of this hydrolysate consisted of small peptides with only a small fraction (7.42%) higher than 10(3) Da but lower than 3 x 10(3) Da. The nutritional quality of the whey protein hydrolysate was good as it resulted in high nitrogen protein utilization and biological value as compared to the protein o f reference (casein plus 5% DL-methionine). However, the protein effic iency ratio was slightly lower for the whey protein hydrolysate as com pared to the control protein. The antigenicity of the whey protein hyd rolysate was about 5 orders of magnitude lower than that of beta-lacto globulin, and it showed therapeutic and prophylactic properties in gui nea pigs sensitized with either the native whey protein or the hydroly sate. The chemical, nutritional, and low antigenic properties of the w hey protein hydrolysate make it appropriate for inclusion in enteral f ormulas, although clinical trials should first be carried out.