Authentication and traceability of Italian extra-virgin olive oils by means of stable isotopes techniques

Authentication and traceability of Italian extra-virgin olive oils by means of stable isotopes techniques Certificazione e tracciabilità di oli extravergini di oliva italiani attraverso tecniche isotopiche Silvia Portarena, Marco Lauteri, Olga Gavrichkova, Enrico Brugnoli CNR - Istituto di Biologia Agroambientale e Forestale, Via G. Marconi 2, 05010, Porano, Italy The aim of this study was to discriminate, by means of Isotope Ratio Mass Spectrometry (IRMS), extra-virgin olive oils originated from different areas of Italy. About 377 samples of extra-virgin olive oils from nine different Italian regions, ranging from North to South, and from three different years of production (2009, 2010 and 2011) were analysed. The statistical analysis of data shows a correlation among oil ?13C and ?18O, latitude, mean annual temperature and mean annual precipitation of the different. No correlations were found concerning the mentioned variables versus both elevation and longitude. The effect of year of oil production was found significant, especially for ?18O. As expected, the olive oil samples from Sicilia and Sardegna resulted more enriched in 13C and 18O than those produced in Lombardia. The results highlights a clear trend to cluster oil samples in relation to the different climatic areas of origin. Furthermore, possible differences in the isotopic compositions of olive oil samples from different varieties, were investigated within geographically homogeneous areas. The obtained results indicate that several cultivars from the same areas are discriminated on the basis of ?13C and ?18O values of the corresponding oils. This latter observation suggests that a particular care should be deserved to understand likely differences in ecophysiological characteristics among the different olive genotypes.