Casein - the key to improved cheese production

A more direct method of measuring casein in cow and buffalo milk has been developed in Italy using Fourier Transform Infrared (FTIR) analysis.

In Italy 80% of the country’s milk supply is used for making cheese. The casein content is therefore of great interest. For instance, in long-ripened hard cheeses such as Grana Padano and Parmigiano Reggiano, a 0.1% variation of the casein number (casein / total proteins) translates into 0.30 kg more or less cheese for every 100 kg of milk processed.

For many years, this casein number, where casein is calculated as a fixed percentage of the total protein content, was considered to be an adequate indicator. More recently, work by Italian laboratories has shown that there is significant variation in the relationship between total protein and casein. This has led to the development of a more direct method.

Using the FTIR MilkoScan FT, milk testing laboratories like the Istituto Zooprofilattico Sperimentale della Lombardia in Brecia are now measuring casein directly. The laboratory has offered casein as a payment parameter for milk cooperatives since 2003. This gives a more accurate measurement of casein for payment purposes, rewarding farmers who can deliver high casein milk. Casein is also an important parameter for measuring high-value buffalo milk used to make buffalo mozzarella.

Dr G. Bolzoni who is responsible for the National Reference Centre of cow's milk quality at the Istituto Zooprofilattico Sperimentale della Lombardia says: "Since 2003, we have been analyzing the casein content of about 120.000 samples of bulk milk with annual averages between 2,55 and 2,64 g/100ml; that means casein index variations between 0,762 to 0,781.The experience gained over the years has highlighted that the casein content varies during different periods of the year, depending especially on the source of the milk. This makes the casein value determination based on a mathematical approach from the protein content in the milk inadequate."

More about the Istituto Zooprofilattico Sperimentale della Lombardia can be found at: www.bs.izs.it

Published:
2006-11-02