WPC is much less heat stable than MPC. When WPC is heated under ultra-high temperatures or retort conditions, the native whey unfolds and aggregates, causing gelling. Whey proteins also denature and lose solubility when exposed to ultra-high temperatures. As a result, WPCs cannot be used in large amounts in applications where a high heat step is needed in processing of a product, such as RTDs.
MPCs are primarily casein based and have high heat stability. Casein in MPC is in micellar form, or spherically shaped molecules while in water. A small amount of complex polyphosphate needs to be included in the formulation to retain heat exposure-induced casein micellular aggregation.
In addition, heat exchanger fouling due to poor heat stability can shorten processing run times, increase cleaning costs and negatively impact overall production efficiencies for dairy ingredient end-users. With MPC/MPI having considerably better heat stability, it is much better suited for RTDs or other high-heat applications.