A protein concentrate comes from a technique called ultrafiltration. This technique, when performed cold, does not denature the protein because the milk is not heated. This method consists of using membranes containing microscopic holes to retain the proteins and let the rest, ie water, sugars, fats and minerals, pass through.
The protein powder obtained by this technique contains around 80% protein.
Microfiltration technique: this technique is mechanical and therefore natural. We use the same process as for protein concentrates, but the pores of the membranes are even smaller (0.1 to 10 mg). The protein is thus more purified and can reach 95% concentration. This is the least aggressive technique, and the protein keeps its biological properties. The only negative point about such a protein is its price – this process is expensive.
Ion exchange technique: This is a process of concentration and purification on ion exchange columns. This technique requires the use of chemical elements (chloridic acid…) so as to remove only the protein of interest. It’s an aggressive treatment that removes all lactose, fats and impurities, but the quality of the protein is slightly impaired.
The protein powder obtained by this technique contains around 90% protein.
This technique starts from a protein concentrate or isolate that will undergo hydrolysis, which amounts to digesting the protein chemically to allow the protein to be assimilated very quickly. Thus, casein hydrolysate is comparable to whey hydrolysate in terms of speed of digestion.
The drawback with this technique is the bitter taste that results.