Concentrates: that are sold for muscle building purposes will usually be up to 70%-80% protein and around 7% fat, 7% lactose and havelow cholesterol counts. They are usually processed via a process called ultrafiltration. Whey is also used in food manufacturing ie: cakes, biscuits and even crisps! Those these powders will be lower in protein. Whey powders can go as low as 30% protein.
Isolates: are processed further to remove the fat, and lactose, they are 90%+ protein by weight. There are two main processes for producing whey protein isolates. CFM™ and ion exchange. CFM isolates are generally considered superior as they are produced under low temperature and low acidic conditions thus helping retain it's biological activity. Ion exchange isolates, while they may have a few more grams of protein than CFM isolates, the important health boosting subfractions found naturally within whey are very much reduced due to it's production process which uses hydrochloric acid and sodium hydroxide to seperate the proteins. As a result, ion exchange isolates usu
ally contains 3 times the sodium of CFM isolates.
Hydrolysates: are partially hydrolyzed,predigested, whey proteins that are therefore more easily assimilated, but their cost is usually higher. Highly-hydrolysed whey may be less allergenic than other types of whey. They are also usually very bitter in taste.
Whey protein powder can be expensive if you just go for the one with all the marketing hype and athlete endorsements! But if you look around and compare prices you'll find it can work out cheaper per gram than most protein food sources!! Additionally the above whey proteins can usually be found in unflavoured versions which avoid all the artificial sweetners and flavourings etc and are usually cheaper too! Another point to remember is whey will generally have 18-24 months shelf life from it's production date so, like most things, it makes sense to buy it in bulk! You'll almost always get a better deal!