Protecting Parmigiano: sensor system sniffs out the real thing

Parmigiano Reggiano – commony known as ‘Parmesan’ – is one of Italy’s most iconic cheeses, and as a result one of the most counterfeited worldwide. Now, researchers say they have developed a simple way to separate real from fake.

Their device combines gas chromatography-mass spectrometry (GC-MS) with solid-phase micro-extraction (SPME) and a nanowire gas sensor in a portable ‘artificial nose’, that allows cheeses to be distinguished using the volatile organic compounds (VOCs) that are responsible for their characteristic aroma and flavour.

The team, from the University of Brescia and Institute of Biosciences and Bioresources in Italy and the company Nano Sensor Systems, used the device to analyse 58 VOCs - alcohols, aldehydes, hydrocarbons, esters and ketones – and identified just six that could be used to distinguish Parmigiano Reggiano from cheeses produced in the US and Germany with 80 per cent accuracy, as confirmed by traditional lab techniques.

“The aim of the work is to find an innovative and rapid method that does not destroy the sample under analysis in order to reduce and control fraud,” they write in the Journal of Food Engineering.

Parmigiano Reggiano has Protected Designation of Origin (PDO) status from the European Commission, and its production is restricted to provinces of Parma, Reggio Emilia, Modena, Mantova and Bologna. It is a premium hard cheese with a long aging process (12 to 36 months), and around 3m wheels are produced every year.

Fraudulent copies account for  between 20 and 40 per cent of the market, and the US is a big market for copycat cheeses, say the researchers. They note the Parmigiano Reggiano Cheese Consortium (CFPR) reports that in 2013 100,000 tonnes of cheese sold as Parmesan in the US, while just 6,500 tonnes of genuine Parmigiano Reggiano were exported from Italy to the US.