Purified whey proteins provide several health enhancing benefits, making them well suited for clear bottled drinks (think protein-fortified 7UP), nutraceutical foods, infant formulas and other applications. Until recently, the challenge has been finding an economical means of separating whey proteins on a large scale.

Researchers at the Wisconsin Center for Dairy Research (WCDR) at the University of Wisconsin-Madison, have recently developed a process concept known as "whey refinery" to manufacture as many as five different purified whey proteins rather than just one, as is currently the practice.

With the whey refinery method, protein from the incoming crude whey stream is captured all at once onto an ion exchanger and washed free of lactose, minerals and fat. Removing non-essential ingredients and reducing the volume of solutions to be processed downstream increases throughput, capacity and the selectivity of downstream separation processes, thereby reducing costs.

"The process fractionates proteins from whey rather than concentrating them from whey, as would be the case ultrafiltration," explained Mark Etzel, associate professor of food science and chemical engineering at University of Wisconsin. "We can fractionate whey into five different proteins simultaneously, one at a time, or in any combination."

He noted that dairy protein fractions such as lactoferrin (LLF, lactoperoxidase (LP) and whey protein isolates (WPI) have been successfully separated with this technology, resulting in unique cost benefits. Because integrated separation allows for specific proteins to be separated on an "as needed" basis (depending on market value and demand) the separated whey proteins are more cost-stable.

Etzel said the technology may be useful in developing specialty foods. "People with the genetic defect phenlyketouria, or PKU, are sensitive to the amino acid phenlylalanine and, as a result, must adhere to zero- or low-protein diets," Etzel explained. "With the whey refinery process, we could fractionate the glycomacro peptide -- the one protein that does not contain phenylalanine -- and use it as an ingredient in foods for people with PKU."

Etzel added that the "whey refinery" process is still in the prototype stage.