Ion-Exchange Whey Protein Isolate

While grocery shopping the other day, my wife showed me a product whose first ingredient was ion-exchange whey protein isolate and asked me what that was. My next blog post, I said excitedly.

Let's break that mouthful down into parts.

Mammal's milk contains all the nutrients needed for a baby of that species to survive on even when eating nothing else. Even so, milk is mostly water. Cow's milk, for example, is 87% water. That remaining 13% is known, straightforwardly, as milk solids and has all the fats, proteins, and carbohydrates, along with the mineral nutrients like calcium and potassium. About 27% of milk solids in cow's milk are proteins. There are actually large numbers of different proteins in milk with each animal's milk containing a different spectrum of proteins. Fortunately, for our purposes, we can reduce that complicated chemistry to two major families of proteins, the casein family and the whey family.

The serum (whey) protein family consists of approximately 50% ß-lactoglobulin, 20% α-lactalbumin, blood serum albumin, immunoglobulins, lactoferrin, transferrin, and many minor proteins and enzymes.

Cow's milk is about 80% casein proteins and 20% whey proteins.

If you do the math, whey proteins are only a very small fraction of cow's milk - .13 x .27 x .20 or .007, meaning seven-tenths of one percent of the whole.

That small percentage has large consequences for us. The presence of any milk protein in a food is a warning that those with milk allergies should avoid the food. That's true even though technically some people are allergic specifically to the casein protein rather than the whey protein.

Lactose intolerance involves only the lactose, which is milk sugar rather than protein. But when milk is broken down to components for use in food processing, the first item to separate out is the casein protein. These are curds, as in curds and whey. (The separation takes much additional work to be complete, which is why anybody with a milk allergy is warned against any food with milk protein. An allergy can be triggered by millionths of a percent of protein.)

The whey fraction of the milk, as it's called, consists of much of the liquid and nearly all of the whey protein and lactose. If you remove the liquid you get dry whey protein or whey protein concentrate, anywhere from 29% to 89% whey protein. That can include a lot of lactose. For that reason those of us who are LI are always told to watch out for foods with whey protein if we're avoiding lactose.

For some extra expense, whey protein concentrate can be further purified. When the whey protein content goes over 90% it is known as whey protein isolate. And if you continue the process, all of the lactose can be removed. That's how you can see foods or whey protein supplements that claim to be lactose-free.

How to purify the whey? Two basic processes, one mechanical and one chemical.

Microfiltration and ultrafiltration (MF/UF) are just what they sound like. They sieve the particles in the whey solution for ones that are the right size and shape.

Ion-exchange is the chemical process, or technically a chemical/electrical process since the use of chemicals produce an electric charge on the proteins that can be exploited to separate them.

For our purposes, ion-exchange whey protein isolate is the better bet, since it does a better job of lowering the final lactose content. If it's strictly the protein you're looking for, MF/UF whey protein isolate does a better job of preserving all the good protein fractions.

From the consumer point of view, having an unexplained five word ingredient like ion-exchange whey protein isolate violates all the standards of the "eat simple food that you know" proselytizers.

But it's great column fodder for me. Thanks, food industry!

Information has been taken from:
• The Whey Protein Institutes's FAQ (http://www.wheyoflife.org/faq.cfm#1)
• Cornell University's "Whey Protein" page (http://www.milkfacts.info/Milk%20Composition/protein.htm)
• Neutraceutical World's "Whey Protein Isolates - Production, Composition And Nutritional Facts" by Matthew Deshler(http://www.nutraceuticalsworld.com/contents/view/12743)
• BodyBuildingforYou.com's "How whey protein is made" pages (http://www.bodybuildingforyou.com/protein/whey-protein-processing.htm)