Dairy processors are constantly searching for new ways to increase product yield without compromising on the things that matter most: efficiency and quality. Membranes enable manufacturers to achieve this goal, especially as innovations like anti-fouling chemistries push yield potential higher.

Ultrafiltration (UF), microfiltration, reverse osmosis (RO) and nanofiltration systems have long helped dairy processors to capture protein and solids that might otherwise be lost. Yet, actual yield is strongly influenced by feedstock pretreatment, operating conditions and overall system design.

A 2025 study published in Foods examining whole-milk ultrafiltration showed that controlled ultrafiltration temperature and homogenization improved protein retention, maintained higher flux over time and minimized fouling. These results reinforce that yield gains are not just influenced by membrane material, but also upstream processing conditions.

Jon Goodman, ZwitterCo’s vice president of food processing and specialties, and Scott Brown, business development manager, explain, “Maximizing product yield may potentially mean different things to different processors. We interpret this by asking, ‘How might a customer increase the total value of product they produce using the same piece of equipment and the same fixed costs?’”

Goodman and Brown note that membranes can contribute to increased value in three main ways:

• More operating hours between cleanings, leaving more time for preventative maintenance, increased production hours or other higher-value activities.
• Higher operating flux, offering increased product quantity with the same solids, or the ability to produce higher-value products with higher solids.
• Reducing product loss, which is generally focused on protein loss.

The ZwitterCo executives suggest a few key membrane properties are essential to success:

• How easily a membrane may be cleaned.
• Membranes that offer a higher sustainable average flux.
• Membranes that pass less protein over time.

For whey processors, UF and RO are essential for producing high-value ingredients, such as whey protein concentrates and isolates.

“Membranes have nearly 40 years of proven performance in the dairy industry and remain the most effective, cost-efficient technology for producing high-value dairy-based ingredients,” Goodman and Brown explain. “This extends beyond the membranes themselves to the entire membrane process; system and process design, including diafiltration, cleaning and operational excellence by processors.”

A 2024 study published in Membranes reported that integrating ultrafiltration, nanofiltration and diafiltration in whey processing produced WPC (whey protein concentrate) with around 88% protein while enabling significant water reuse. The study also noted improvements in throughput and protein recovery compared with conventional systems, showing that optimized membrane processes can improve both protein yield and sustainability in high-volume dairy operations.

Choosing the right membrane

Membrane choice can greatly impact productivity, especially in plants that are near capacity or face persistent cleaning challenges. Goodman and Brown point out that membrane choice has the greatest impact for these plants, as well as operations looking to increase value without investing in new equipment. In fact, the 2024 Membranes study confirms that system design and membrane selection together propel yield and operational efficiency.

Membrane evolution, historically, has been incremental: small gains in surface area, spiral construction and durability. But the latest advancements in anti-fouling chemistries are enabling step-change productivity improvements, according to ZwitterCo’s executives.

Goodman and Brown explain: “Most developments today focus on chemistries that are more anti-fouling and may be cleaned faster and easier than conventional membranes. This shift marks a meaningful departure from the long period when membranes were nearly all the same, and much of the industry’s progress depended on process design rather than the membranes themselves.”

Anti-fouling innovation continues to drive productivity gains. Today’s membranes enable shorter cleaning procedures by eliminating steps from the program, saving precious time at the plant. These gains can be further enhanced with updated cleaning programs, Goodman and Brown state.

Benefits for dairy plants

Even more attractive is the potential for higher sustainable operating flux. The limiting factor for operating flux is the formation of a gel layer on the membrane surface, which becomes thicker at higher solids (and is why flux is much lower at the back end of systems than the feed end), Goodman and Brown say. “Proteins stick less to an anti-fouling membrane than to conventional chemistries, just like eggs stick less on a Teflon-coated frying pan than on a cast iron skillet. In production systems, higher operating flux has been observed and attributed to the formation of a thinner gel layer on anti-fouling membranes.”

By optimizing both membrane and overall process conditions, processors can see direct benefits at the plant. Fewer cleaning interruptions translate to less unnecessary downtime, as well as optimized resource usage. Higher sustainable flux increases throughput without the significant investment of new equipment. The 2025 Foods study reinforces that controlled process conditions maintain higher flux and reduce fouling, directly improving operational efficiency.

Membrane technology continues to drive yield improvements in dairy processing, benefiting protein recovery, reducing cleaning time and minimizing product loss. Advanced membranes, especially those with anti-fouling properties, enable dairy processors to extract greater value from each liter of milk or whey. As membrane technology continues to evolve, integrating these innovations with operational best practices promises strong gains for both efficiency and profitability. DF