Whey protein is essentially the uncurdled liquid remains of milk that coagulates after the cheese has been strained out. Whey is made out of amino acids, which are the building blocks of protein. There are eight essential amino acids that the body cannot make on its own and must be obtained through the diet—including a ninth made from the others. The Whey Protein Institute states that whey is useful for its ability to build muscles, support bones and improve immune function, in addition to its nutritional components, but before it reaches the consumer, whey must be processed first. The ion exchange is one optional way to process whey.
According to Medline Plus, an ion is an element or molecule with an electrical charge. Most atoms have a neutral charge because the negatively charged electrons and positively charged protons are at an equilibrium. But if the total number of electrons changes in relation to the number of protons, then the atom will acquire a charge in either direction. A positively charged ion is called a cation. A negatively charged ion is called an anion. Some atoms are more likely to pick up a charge than others—for example, a hydrogen atom with a single proton is very common—so they are predictable by nature.
The purpose of an ion exchange device, as its name implies, is to exchange ions between two solutions or substances. One such example is electrolytes, which are electrically conductive substances that contain a number of free ions. Common electrolytes include sodium, potassium, calcium, chloride and bicarbonate. This action allows the substances in the whey liquid to be separated according to their basic electrical charge.
Two chemicals are used to achieve separation: hydrochloric acid and sodium hydroxide, both of which are used to form a solution that exchanges ions with the whey protein. It's somewhat similar to the effects of a water softener. The electrical charge of the proteins then attaches them to the resins of the reaction vessel.
The intent of an ion exchange process is to purify and concentrate whey protein. The typical protein content of whey powder can range between 35 and 95 percent. The more it is purified, the higher the concentration it will be. In addition, ion exchange techniques cost only about a fifth as much as a physical filtration system, in which the whey protein is strained from its surroundings.
Because of the chemical reagents used, such as hydrochloric acid, pH sensitive factions of the whey protein material may become denatured. This means that the amino acids are degraded. Some of the components often denatured include immunoglobulins—or antibodies—glycomacropeptides and other important immune system agents that boost anti-viral and anti-microbial activities. Some essential amino acids may also be lost, in addition to the ability to improve the absorption of vitamins and minerals in the digestive process.