Numerous dried dairy ingredients are produced from whey, the liquid drained off during cheesemaking.
“The component we most want to isolate and harvest from whey — protein — is at a very low concentration,” said Lloyd Metzger, PhD, professor and chair of dairy education at South Dakota State University, and director of the Midwest Dairy Foods Research Center, Brookings, SD. “Whey is primarily water and lactose. It is only about 0.8% total protein,” he observed.
Separation technologies can isolate specific components of whey or any other fluid milk stream. These methods produce concentrated forms of micro and macro nutrients with unique functional and nutritional properties.
For example, bakers know that lactose, a reducing sugar unique to milk, enhances browning. Lactose is not fermented by yeast. Rather, it enters into the Maillard browning reaction with amino acids and caramelizes readily under the influence of oven heat.
When it comes to whey proteins, some companies make cheese just to purify the whey. They sell the cheese to marketers and distributors and focus their efforts on producing whey ingredients.
Dr. Metzger spoke this summer at Alpha Summit 2015, a whey protein conference held at Jerome, ID, sponsored by Davisco, Eden Prairie, MN, a business unit of Agropur Inc., Longueuil, QC. He explained the differences and similarities of separation technologies, including membrane filtration and ion-exchange, and how the two can be used in combination to isolate and purify desirable components of whey.
“Ion exchange yields protein fractions with fewer impurities,” he said. “The presence or absence of these impurities impacts amino acid profile as well as the ingredient’s solubility, heat stability, gelation and foaming properties.”
Davisco manufactures a range of ingredients including whey protein concentrate (WPC) and whey protein isolate (WPI). The company commercialized its ion-exchange technology about five years ago to manufacture a proprietary WPI with a leucine content of 13.1%, which is much higher than the 11% found in most WPI ingredients. Leucine, an amino acid, is associated with promoting muscle health, making WPI attractive for sports nutrition products like protein bars and muffins.
The company now uses the technology to isolate and purify other components of milk, most notably alpha-lactalbumin, the primary protein in human milk.In addition to being used in infant formula to more closely mimic mothers’ milk, alpha-lactalbumin has potential in mood-enhancing foods. This is because it is uniquely rich in tryptophan, the precursor to the neurotransmitter serotonin that has been shown to affect mood. Studies show that alpha-lactalbumin improves morning alertness and, in the evening, assists with focusing and attention. Think wake-me-up muffin and finals’ night snack crackers.