Geographical discrimination of extra-virgin olive oils from the Italian coasts by combining stable isotope data and carotenoid content within a multivariate analysis

• δ13C, δ18O and carotenoid content of oils along the Italian coast were analysed.
• Chemometric analysis of all data correctly classified up to the 82% of samples.
• Coupling of IRMS with RSS is a promising tool for food authentication.
• Perspectives of these coupled techniques in traceability studies are discussed.

We have determined the isotopic composition and the carotenoid contents of 38 extra-virgin olive oils (EVOOs) from seven regions along the Italian coasts, by means of isotope ratio mass spectrometry (IRMS) and resonant Raman spectroscopy (RRS), respectively. The application of linear discriminant analysis to our overall results demonstrated the combination of isotope and carotenoid data is a promising method to discriminate EVOOs from production sites that are impacted by similar geographical and climatic parameters. In particular, this dual approach allowed correct classification of 82% EVOO samples, while separate IRMS and RRS investigations were able to discriminate only samples from Sicily and Latium, respectively.