BIOLOGICAL EVALUATION OF WHEAT SUPPLEMENTED BY A WHEY-PROTEIN CONCENTRATE OR WHEY CHEESE ON GROWING-RATS

Whey contains proteins of high nutritional value which are valuable as supplements to lower quality proteins, cereal proteins. Procedures for production of concentrates of whey protein have been developed but are generally expensive. Thus, nutritional properties of whey products which are less expensive need evaluation. Whey cheese is a traditional food in Scandinavia, but its protein is considered of low nutritional value. This paper describes determination of biological value and true digestibility on growing rats of mixtures of wheat and whey cheese as well as of wheat and whey protein concentrate. Additions of protein from whey protein concentrate or whey cheese to wheat resulted in mixtures with higher biological values although in most cases whey protein concentrate was as a wheat protein supplement superior to whey cheese. For example, a mixture containing 50% protein from wheat and 50% protein from whey protein concentrate had a biological value of 92, while the corresponding figure for a mixture of 50% wheat protein and 50% whey cheese protein was 75. Nevertheless, the improvement in protein quality after addition of a relatively small proportion of protein from whey cheese to wheat is considerable and probably could be significant in human nutrition. © 1979, American Dairy Science Association. All rights reserved.