I've had people confused and ask about the different filtration processes, so here it is:
Ionic Exchange processing involves separating proteins based on their electrical charge. Two chemicals are used to achieve this: hydrochloric acid and sodium hydroxide. Ion Exchange processing costs only about 1/5 as much as setting up microfiltration. However, because of the chemical reagents used, pH sensitive fractions are damaged and some amino acids are denatured--noticeably, the glycomacropeptides, immunoglobins, and alpha lactalbumin. These are the valuable and health promoting fractions lost in Ion Exchange process. This results in higher concentration of other fractions such as beta-lactoglobulin--known as whey's least interesting and most allergenic subfraction..
One benefit of Ion Exchange is that it yields the highest protein levels and has less fat/lactose of any whey processing method (on a gram-for-gram basis), but this is a heavily marketed ploy to get consumers to buy these, despite the disadvantages stated above.
Microfiltration uses high tech ceramic membranes to filter the whey. No chemical regents are used so majority of biological fractions are intact without being damaged. Ultrafiltration is a similar method to the microfiltration but uses smaller pores with higher pressure. By using membrane filters, undesirable components (fat/lactose) are filtered out. The particles are separated based on their molecular size and shape. The advantage of this process includes:
-Minimal denaturing of protein
-Preserved biological fractions
-Better amino profile
CROSS FLOW MICROFILTRATION (CFM):
One of the best methods in the market today. CFM is patented and owned by Glanbia (one of the largest dairy industry that recently bought Optimum Nutrition). Therefore, there is an added cost for manufacturers to use this method--resulting in higher price. Once again, very similar to microfiltration but is kicked up a notch to produce an isolate that is greater than 90% protein with no fat or lactose, and leaves almost 100% of the protein and the important peptides intact. The CFM includes the advantage of micro/ultrafiltration plus:
-Contains more calcium and less sodium
-Highest level of undenatured protein