Nanofiltration and Its Components- Whey Processing

Nanofiltration (NF) is a cutting-edge membrane filtration technology used extensively in food and dairy processing. Operating between ultrafiltration and reverse osmosis, nanofiltration allows the selective passage of monovalent ions and small organic molecules while retaining larger solutes such as proteins, lactose, and minerals.

NF membranes typically operate under medium to high pressures (5–40 bars) with pore sizes between 0.5 to 2 nanometers, offering superior separation performance. These membranes are ideal for partial demineralization, volume reduction, and concentration processes in the dairy industry—making them a go-to solution for food technology consultants and engineering experts in dairy plant design.

Membrane Design In NF

The spiral-wound membrane configuration is most commonly used in NF systems due to its compactness and high surface area. Each membrane module includes:

Two polymeric membrane layers
A permeate channel spacer
A porous conductive support to facilitate liquid flow

This structure enables effective retention of high-molecular-weight compounds while allowing salts and smaller molecules to pass through efficiently.

Nanofiltration (NF) in dairy Industry

Nanofiltration has become indispensable for food processing consultants involved in:

Whey concentration
Whey demineralization
Lactose recovery
Production of WPC and WPI

Its ability to operate continuously with high separation efficiency makes it a cost-effective and energy-efficient solution for dairy manufacturers.

Nanofiltration (NF) in Whey processing

Dairy-suitable NF-membranes have a high permeability for (monovalent) salts (NaCl, KCl) but an extremely low permeability for organic compounds (lactose, proteins, urea) with a molecular weight higher than 300 Da.

Whey is the most important byproduct/liquid residue of cheese, yogurt, and casein production and includes a high concentration of valued organic matter. Whey accounts for 80-90 percent of the total volume of milk and contains roughly half of the nutrients found in whole milk: lactose, soluble protein, vitamins, and minerals. It needs to be demineralized before consumption for humans or animals.

Whey is concentrated by evaporation (EV) and then demineralized by electrodialysis (ED) and/or- ion exchange in industrial processes. Nanofiltration (NF) is a great alternative for the partial demineralization of whey.

1. Whey concentration

NF membranes allow volume reduction by increasing dry matter from ~6% to 18–25%. This process significantly reduces transportation costs and storage volumes.

Key advantages:

Removal of monovalent salts (e.g., NaCl, KCl)
Retention of nutritional components like lactose and proteins
Improved efficiency over traditional evaporation (EV)

2. Partial Whey Demineralization

Demineralization improves whey’s nutritional profile for human and animal consumption. NF effectively:

Removes excess sodium, potassium, and chlorides
Retains valuable organic compounds (proteins, vitamins)
Prepares whey for further treatment via electrodialysis (ED) or ion exchange

This method aligns with GMP standards and is favored by food manufacturing consultants for large-scale production.

3. Final Concentration of WPC or WPI

After ultrafiltration (UF), NF membranes are used to:

Further concentrate whey protein concentrates (WPCs) with 35–80% protein
Produce whey protein isolates (WPI) with >92% protein

This step reduces spray drying energy costs, increases plant capacity, and enables production of high-purity protein powders for sports and nutrition sectors.

4. Lactose recovery

NF assists in:

Concentrating lactose from whey/permeate
Reducing mineral content, improving crystallization efficiency
Achieving higher-purity lactose powder

This process is widely recommended by consultancy firms for the food industry focused on maximizing by-product value.

Benefits of NF over EV+ED

Simultaneous concentration and demineralization

Lower energy consumption

Reduced wastewater generation

Cost savings in plant operation and maintenance

Conclusion

Nanofiltration (NF) is transforming the dairy sector through sustainable, efficient, and scalable separation techniques. By integrating NF systems, food processing consultants and food engineering experts can deliver:

Cleaner whey streams
Enhanced protein products
Efficient lactose extraction

With growing demand for high-purity, functional dairy ingredients, NF is a vital technology for any modern food manufacturing plant.

References

PMG Engineering | Build World-Class Food Factories | Article | Nanofiltration and Its Components- Whey Processing

Membrane Design In NF

Nanofiltration (NF) in dairy Industry

Benefits of NF over EV+ED

Conclusion