Concentrated, fermented (cultured) dairy products are more popular than ever before, and consumer demand for new products with low fat and high protein is growing rapidly. This rising demand is leading to increased focus on the membrane technologies, which ensure that the desired level of protein remains in the finished product.
Traditionally, concentrated, fermented dairy products have been made by drainage or centrifugation. However, membrane filtration offers an interesting and profitable alternative with several positive characteristics.
The ultrafiltration (UF) membrane separates the feed (e.g. skimmed milk) into two streams, allowing water, dissolved salts, lactose, and acids to pass through it in either direction, while retaining (and thereby concentrating) proteins and fat.
More and more often, products like Greek style yoghurt, skyr, labneh, and quark are concentrated by means of UF, which results in a higher whey protein level in the product – and thus a higher yield - than when processed by centrifuge.
UF concentrates the whey proteins in the fermented product, making it smoother and giving it a soft mouth feel and homogenous texture with an appealing surface.
Unlike separators, which are product specific, an UF plant is extremely flexible, as it can be used for various product recipes, independent of fat or dry matter content. When using separators the final product is “fixed” and any new product development will require investment in a new separator.