U.S. Dairy Products > Milk Proteins > Milk Protein Categories

Milk Protein Isolate

MPIMilk protein isolate (MPI) is produced by filtration methods (ultrafiltration and diafiltration) that capture essentially all the casein and whey proteins contained in the raw material stream of the finished product. This results in a casein-to-whey-protein ratio equivalent to that of the original milk (approximately 80:20) without combining separately produced casein (caseinate) and whey proteins. MPIs have a minimum of 90% protein (generally in the range of 90% to 91% protein by weight).

Composition of Milk Protein Isolate (MPI)

ProductProtein %Fat %Lactose %Ash %Moisture %
MPI 89.5 min* 2.50 max 5.0 max 8.0 max 6.0 max

(*)  Protein content over 80% is reported on a dry basis, all other parameters are reported "as is" aAmerican Dairy Products Institute proposed standards, 2014    

On the Label

Product labeled as MPI must contain a minimum of 89.5% protein.  

Typical Applications

MPIs are commonly used in value-added products like dietetic formulations, high-protein clinical formulations and nutritional bars.