Why an airtight separator is best for product quality

One of the first decisions when considering a new separator is whether to choose one that excludes or allows air to enter during the separation process.

A white door to an airtight separator

Two types of separator dominate the market today: separators that are airtight (also known as closed), and semi-open separators that allow air inside when the product enters and exits the separator.

Airtight separators offer several advantages over semi-open varieties. A prime benefit is that their air-free environment is better at maintaining the quality of the product during the separation process.

“In a dairy context, it’s about contributing to preserving the quality of the milk in the line,” explains Erwin Kaschmieder, senior dairy technologist at Tetra Pak. “An airtight separator reduces the risk of quality degradation.”

Air during production disrupts the membranes surrounding the fat globules in the milk, causing free fatty acids to leak into the product or fat globules to fracture into smaller entities. A closed separation process limits the risk of this happening.

Liberation of free fatty acids can cause lumping issues further downstream and also raises the risk of oxidation, which can have a negative impact on the sensory properties of the product.

Limiting the risk of free fatty acid liberation is important throughout the milk processing line – all the way from farmer to end product.

This is a key consideration for dairies, whether they are producing skimmed milk or milk for cheese or powder production.

Because airtight separators have no air interface and no air pick-up, they deliver a gentle separation treatment that ensures the lowest fatty acid leakage and best product quality as a result.

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