New dairy standard to improve milk testing accuracy

A key analytical standard for the dairy sector has been updated following joint work between ISO and the International Dairy Federation (IDF).

ISO 9622/IDF 141: 2013, ‘Milk and liquid milk products - Guidelines for the application of mid-infrared spectrometry’ contains guidelines for the testing of milk and milk products with mid-infrared instruments. These instruments are extensively used in laboratories and dairy plants worldwide.

The new version now fully covers the use of Fourier transform infrared (FTIR) technology, which improves the routine compositional analysis of milk, according to Paul Sauvé and Harrie van den Bijgaart, two experts involved in the development of the standard.

“FTIR analysers measure the full mid-infrared spectrum whereas the description in the old standard was limited to traditional wavelengths,” said Sauvé, who is an expert at the IDF.

“This means we can be more accurate with fat and protein measurements and test for more components such as urea and added water.”

This increased accuracy is important for products intended for export and trade and will help set pricing in milk payment schemes, as milk prices vary depending on the fat and protein contents, according Harrie van den Bijgaart, chair of the ISO committee that developed the standard.

“Furthermore, it could lead to the development of new tools to help dairy farmers optimise their herd management; for example, indicators for ketosis and feed efficiency,” van den Bijgaart said.

The fact that multiple parameters can be measured at the same time reduces costs in testing laboratories, the organisations say.

The IDF and ISO have been working together for many years to develop and publish standard methods of analysis and sampling for milk and other dairy products.

“Joint international standards are important to prevent duplication of work in the development of standards and to avoid incongruences,” van den Bijgaart said. “That is what standardisation is all about: reaching consensus between stakeholders in the broadest sense and documenting it.”