Summary
- Whey is increasingly being upcycled into high‑value ingredients, helping processors move beyond treating it as a low‑value by‑product.
- Membrane filtration technologies enable the separation of whey into premium ingredient streams such as proteins, permeates, and mineral fractions.
- Filtration supports reduced‑lactose product development by removing lactose physically, reducing reliance on enzymatic hydrolysis.
- Upcycling whey enhances sustainability and profitability, recovering valuable solids and clean water while diversifying processors’ product portfolios.
Whey is often described as dairy’s ‘liquid gold’, but it isn’t always treated as a valuable side stream.
A by-product of cheese production, whey’s disposal is par for the course for many processors, who may choose to sell it cheaply, incorporate it into animal feed, or dispose of it as waste.
While this routine is still embedded in many global dairy operations today, businesses have been increasingly investing in processing technology to upcycle the by-product into high-value ingredients.
This strategy can help advance sustainability targets; address growing trends such as protein fortification and clean-label, and diversify a company’s product portfolio outside of traditional dairy commodities.
Moving into high-performance ingredients can enable processors to mitigate risk, particularly if commodity price pressures arise or there are tariff headwinds for specific dairy products in certain markets – as is the case with cheese exported from the EU to China currently. In addition, processors such as Fonterra have chosen to focus increasingly on ingredients – having offloaded most of its consumer and branded dairy to Lactalis in a major industry deal.
Membrane filtration systems are the most common way to upcycle liquid whey into high-value ingredients. Different types of technology are used to derive these ingredients, as Fiona Liebehenz, Tetra Pak vice-president, key components, plant solutions & channel management, explained. “By combining microfiltration, ultrafiltration and nanofiltration, dairy processors can separate components based on size and functionality. This facilitates the creation of distinct fractions that can be directed into different markets.”
For example, membrane-based fractionation is a way to turn milk and whey into multiple high-value ingredient streams, as opposed to a single main product plus a low-value by-product. “Milk and whey can be split into high-protein streams: such as micellar casein concentrates or native whey protein fractions,” she said.
Native whey proteins can be used in sports and medical nutrition applications; permeates – in bakery and confectionery; and mineral fractions – in infant formula products. Secondary streams, such as permeates, are rich in lactose and minerals.
“These permeate and mineral fractions are ingredients in their own right: used across confectionery, bakery, beverages, infant nutrition and specialised dietary products,” Liebehenz added.
Membrane filtration also supports the production of reduced-lactose products. Instead of relying on enzymes to break down lactose, manufacturers can use the technology to remove a portion of the lactose physically.
“In ultrafiltration for fermented dairy, proteins are retained while lactose and minerals pass through the membrane,” Liebehenz said. “This method increases protein density, while at the same time, lowering the lactose content in the remaining product stream. It also reduces the need to rely primarily on enzymatic hydrolysis as the main step for lactose reduction, because the formulation shift is achieved through membrane separation first.”
Finally, membrane systems can enhance sustainability. “Reverse osmosis can be used to recover those solids for reuse while producing clean water suitable for recycling in the plant,” she noted.
