The most common application of membrane filtration in the dairy industry is the treatment of whey from cheese manufacture.

If the whey is to be transported for further processing or to be used as animal feed, it is typically concentrated 1.5 to 3 times in an RO plant. The permeate is used as process or CIP water.

If the whey is concentrated using NF, the retentate is simultaneously demineralised. In certain cases, NF can be used as a cost-effective alternative to RO.

Whey that has been concentrated using RO or NF can be processed directly into whey powder.

UF allows the concentration of whey proteins along with the simultaneous separation of minerals and lactose. A standard UF plant typically produces whey protein concentrate (WPC) with a protein content of 34 to 85%.

By using supplementary techniques, such as chromatography and microfiltration, it is possible to isolate the proteins even further to produce whey protein isolates (WPI).