Whey Protein Isolates and Microfiltration
Whey Protein Isolates (WPI) are at a higher level than WPCs. They are created during a process by which WPC is purified by “isolating” the highly soluble protein found in whey from the fat and lactose leaving less than 1% lactose and less than 2% of the fat found in the WPC, and by completely removing the damaged protein, salt, etc. There are two main processes by which WPI is produced, and due to different temperature, pressure, etc. applied the two methods yield very different end products.
The original ion exchange, or “column method,” consists of pumping whey through a column impregnated with a special resin that causes different ions from the protein to bond or stick to the resin and the remaining impurities flow through the column and are discarded. The main problem with ion exchange is that some of the beneficial protein fragments will not bind to resin and will be discarded as they also flow through the column. Steps will then be taken to add this protein back in, but sodium is inadvertently added as well.
This can result in a high sodium content in the final product, as well as up to 10% denatured protein, proteins that have been damaged and are not beneficial to the body. The benefits of the Ion Exchange process is that it is able to remove nearly all the fat and lactose creating a product that is up to 90% pure compared to WPC that can only be 85% at its highest quality. A newer method uses microfiltration it usually does not cause the denatured protein.
Microfiltration WPI, one of the highest quality protein supplements, is produced by starting with high quality milk sourced WPC and filtering under low temperature and low pressure allowing only soluble protein to pass through leaving salt, fat, lactose and denatured proteins behind.
The next step is to dry this crystal clear liquid to create a powder, and here is one of the steps where manufacturers can go astray. The only way to create a superior product is to let the liquid dry into a powder by using a low temperature dryer. A low temperature dryer is a very expensive and slow way of creating a powder from the crystalline liquid.
Many manufacturers opt to use a high temperature dryer as it is much faster and cheaper. The whole idea of running the WPC through a membrane was in part to remove denatured protein, so why add a step that takes your product backwards?
