Differences between MPC/MPI milk proteins
MPC/MPI milk proteins have gained prominence in the food industry and specialised nutrition due to their high biological value and diverse applications. Although both are derived from milk and share the natural combination of casein and whey protein, their filtration and concentration processes result in significant differences in protein content, solubility, and end use. Understanding these variations is key to choosing the most appropriate option depending on the objective, whether it be enriching foods, formulating supplements, or developing low-lactose products.
What is MPC and what is MPI?
Milk protein concentrate (MPC) is obtained by ultrafiltration of skimmed milk, resulting in a powder containing between 40% and 90% protein, including both casein and whey protein in the natural proportion found in milk (~80% casein and 20% whey). It tends to retain more minerals, lactose and fat than an isolate, although at reduced levels depending on the degree of concentration.
Milk protein isolate (MPI) has a purity of over 90% protein, with almost all lactose and fat removed. Although it retains the combination of casein and whey, the protein structure can make it difficult to dissolve.
Functional advantages and applications
- MPC combines slow digestion (casein) and fast digestion (whey), ideal for food applications where natural texture and emulsion are desired, such as ice cream, yoghurt, bars, or sauces.
- MPI provides high protein content with minimal lactose, useful in sports supplements or high-performance formulas.
Nutritional and compositional comparison
- Protein content:
- MPC: 40–90%, depending on the grade.
- MPI: ≥ 90%, typically between 90% and 91%.
- Lactose and fat:
- MPC contains moderate levels, especially in lower protein versions.
- MPI retains minimal amounts (<5%) of both lactose and fat.
Solubility and functionality
MPC usually has better rehydration and solubility, thanks to the presence of lactose, which helps to separate powdered proteins or foods. In contrast, MPI can present solubility difficulties after storage, as the almost complete absence of lactose and structural modifications make it difficult to dissolve.
From a functional point of view, MPC provides emulsification, thermal stability, foaming, viscosity and improved texture in products such as yoghurts, ice cream and food bars. MPI, due to its high purity, is used especially in supplements, health products and foods with high protein density without excess carbohydrates.
Common applications of MPC/MPI milk proteins
- MPC: ideal para aplicaciones alimentarias (bebidas lácteas, barras proteicas, helados, quesos reconstituidos, etc.).
- MPI: perfect for sports supplements, medical nutrition, weight management products, or high-protein formulas that are lactose- and fat-free.
Comparative table of milk proteins
| Característica | MPC (Milk Protein Concentrate) | MPI (Milk Protein Isolate) |
|---|---|---|
| Proteína total (%) | 40 %–90 % | ≥ 89,5 %–≈ 91 % |
| Lactosa / grasa | Presente, menos en MPC de alta proteína | Mínima (< 5 %) |
| Solubilidad / rehidratación | Buena (especialmente variedades intermedias) | Puede ser difícil con el tiempo |
| Funcionalidad | Emulsionante, espumante, texturizador | Menor funcionalidad culinaria, más enfoque nutricional |
| Usos típicos | Alimentos enriquecidos, bebidas, postres | Suplementos, barras proteínas, nutrición clínica |
| Costo relativo | Más económico | Más costoso por mayor pureza |
Which one should you choose depending on your objective?
- Functional food formulations: choose MPC if you are looking for texture, emulsion or foaming together with protein content.
- Sports supplementation or low-lactose nutrition: choose MPI, as it offers maximum protein with minimal lactose and fat.
- Balance between functionality and nutrition: Intermediate MPC can offer a good middle ground.
Frequently asked questions about MPC and MPI proteins
Does MPC contain casein or only whey?
It contains both types of protein in natural proportions (≈ 80% casein / 20% whey).
Is it true that MPI is more difficult to dissolve?
Yes, the lack of lactose and possible structural changes can hinder its solubility, especially after storage.
What does MPC contribute to food at a functional level?
Improves emulsions, thermal stability, foaming, viscosity, and texture in multiple food products.
Why is MPI preferred for low-lactose products?
Because its filtration process removes most of the lactose, leaving very low levels that make it suitable for people with lactose intolerance.
Which type offers the best cost/performance ratio?
The MPC offers greater functional versatility at a lower price; the MPI is superior when purity and concentrated protein are prioritised.