Development of a screening method to rapidly discriminate extravirgin olive oil from other edible vegetable oil by means of direct sample analysis with high resolution mass spectrometry.

Extra virgin olive oil is the highest quality olive oil mainly due to its beneficial constituents and nutritional properties. However, olive oil adulteration is a common fraudulent practice by deliberate mislabelling of less expensive oil categories and admixing expensive olive oils with low oils. To protect consumers from such commercial frauds, an easy and fast method to detect the real composition of oil is needed. For this study we used direct sampling analysis (DSA) coupled with a high-resolution mass spectrometer (AxION2 TOF Perkin Elmer) to analyse the fatty acid composition of three types of edible oil: extra virgin olive oil, refined olive oil and seed oil (EVOO, ROO, and SO respectively) to find a marker that could distinguish between them. Good precision in repeatability and reproducibility (RSD% < 15%) was obtained. The fatty acid ratio between the oleic acid/oleic acid dimer was able to distinguish EVOO from the other two types of oil, while the ratio between linoleic and oleic acid was found to discriminate refined oil from seed oil. The development of an easy, fast and cost-effective method can help to limit commercial frauds, increase the number of controlled samples, and enhance food control along the commercial chain. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05063-y.