A new protein isolation process developed by researchers at the University of Wisconsin-Madison, with funding from America's dairy farmers and sponsored by DMI, can make a difference for children with PKU (phenylketonuria), an inherited metabolic disorder that strikes one baby in every 10,000.
Children with PKU cannot metabolize the amino acid phenylalanine, which builds in the bloodstream and can cause brain damage. The PKU diet eliminates high-protein foods such as meat, eggs, cheese, legumes, nuts or even products with regular flour.
GMP, or glycomacropeptide, is one of the only known phenylalanine-free natural proteins. GMP is released when the enzyme chymosin breaks peptide bonds in casein, the major milk protein, during cheese-making. While cheese curds are forming in the vat, the peptide fragment GMP separates into the whey, where it can comprise up to 20% of the whey protein. Ion exchange separates GMP from whey at a purity of greater than 90%. Additionally, GMP has appetite-suppressing properties and also fights tooth decay by preventing the adherence of bacteria on the teeth.