Test can confirm if your Parmigiano-Reggiano is authentic

Traditional Parmigiano-Reggiano originates from only a handful of Italian provinces and commands twice the price of its generic cousins. However, a parmesan scandal reported in February 2016 highlighted how easy it is to doctor the cheese when it’s grated.

News stories described grated Parmigiano-Reggiano, or parmesan cheese, containing cellulose as a filler as well as different, less expensive cheeses. One product labelled as 100% parmesan reportedly contained none.

For producers and consumers of some of the most expensive kinds, this is a big problem, as there was no way to reassure consumers that the artisanal products were authentic. To address this, the European Union established a system to grant a ‘protected denomination of origin’ (PDO) designation to certain products. In the case of Parmigiano-Reggiano, cheeses with the PDO label must meet certain requirements. For example, they must be made out of milk from cows that are not fed silage, a fermented cereal product often used in animal feed.

Augusta Caligiani and fellow researchers wanted to see if detecting compounds associated with these diets would be an effective way to determine the authenticity of PDO-labelled parmesan.

The researchers analysed more than 300 samples of cheeses using a gas chromatography-mass spectrometry method to see if it could help differentiate cheeses from cows fed silage and those that were not. Their findings, which have been reported in The American Chemical Society’s Journal of Agricultural and Food Chemistry, were that samples of Grana Padano, a cheese similar to parmesan but made with milk from cows allowed to eat silage, contained cyclopropane fatty acids. These fatty acids were not in PDO parmesan samples.

The researchers also could tell if a blend of the two cheeses contained 10% or more of Grana Padano. Because the method is simple and fast, the researchers say it could be used in industry to screen large numbers of samples for potential adulteration.