Four dairy proteins with similar names and different jobs. How they are made and where each one fits.
The names follow a simple logic. Whey proteins come from the liquid left after cheese making. Milk proteins come from skimmed milk itself and contain both casein and whey. Concentrate and isolate describe how far the protein has been purified.
Whey protein concentrate
WPC is graded by protein content, most often WPC 34/35 and WPC 80. The lower grades are used in bakery, dairy desserts and confectionery. WPC 80 is the workhorse of sports nutrition.
Whey protein isolate
WPI is filtered further, to around 90% protein or more, with most lactose and fat removed. It is used in clear protein drinks, low-lactose products and bars where every gram of protein counts.
Milk protein concentrate and isolate
MPC keeps casein and whey in the ratio found in milk, with grades commonly from MPC 42 to MPC 85. It is used to raise yield in cheese, to thicken high-protein yoghurt and in nutritional beverages. MPI is the same idea taken to about 90% protein.
How to choose
Start from the protein level you need on the label, then consider behaviour. Whey proteins dissolve clear and digest quickly. Milk proteins are heat-stable, give a creamier body and digest slowly. Price also matters: the higher the protein, the higher the cost per tonne.