Are different heat treatments used in manufacturing MPCs?

YES. Different MPC manufacturers follow their own, unique processing methods. Just as milk powders can vary in heat exposure and heat damage from one manufacturer to another, MPCs can vary from one manufacturer to another. Milk powders are graded according to their heat exposure/damage by assaying the powders for undenatured whey protein nitrogen. The powders are usually classified into low heat (treatment), medium heat (treatment), or high heat (treatment) classifications. A low heat powder would have the least damage from heat while a high heat powder would contain very little, or no undenatured whey protein. The same testing methods can be used to compare heat exposure/damage of MPC powders. The Hungarian Dairy Research Institute, pioneers of MPC manufacture, compared Idaho Milk Products’ MPC 80 to competitive brands from around the world. They used the American Dairy Products Institute (ADPI) Method for Determination of Undenatured Whey Protein Nitrogen in Nonfat Dry Milk (modified to reflect the higher protein content of MPC) to compare heat exposure of the varying MPC powders. By the ADPI testing method, a low heat milk powder is considered to contain a minimum of 6.0 mg undenatured whey protein nitrogen per gram of powder. A medium heat milk powder will contain from 1.51 to 5.99 mg undenatured whey protein nitrogen per gram of powder and a high heat milk powder contains 1.50 mg undenatured whey protein nitrogen or less per gram of milk powder. The results showed that Idaho Milk Products’ MPC had been exposed to significantly less heat than the competitive powders, yielding undenatured whey protein nitrogen values (15 mg per gram of powder) that were almost double that of the next nearest competitor (8 mg per gram of powder). Idaho Milk Products’ MPC had two and a half times the undenatured whey protein of the average competitor MPC (6 mg per gram of powder). At least half of the MPC powders tested by the Hungarian Dairy Research Institute assayed as medium heat powders.