Whey Protein Concentrate as a Milk Extender

Whey protein concentrates, having a gross composition equivalent to that of skim milk, were prepared from cheese whey by ultrafiltration and were evaluated as a milk extender. Nutritional and organoleptic data indicate acceptability for such use. Ash values generally were lowered by ultrafiltration averaging 10.5% for cottage cheese whey and 7.5% for its corresponding concentrate. Vitamins and amino acids in protein concentrates were equal or superior to those of skim milk. All essential amino acids were in excess in the protein concentrate as compared with reference protein of the World Health Organization. Feeding trials of rats indicated bioavailability of the dried concentrates was higher than that of both casein and skim-milk powder. Addition of dried concentrate to nonfat dry milk as a 40% blend raised the protein efficiency ratio of the nonfat dry milk from 2.51 to 2.83. Sensory evaluation indicated that up to 40% concentrate from sweet whey or 20% from acid whey can be blended with skim milk without adversely affecting organoleptic quality.