Stable isotope ecophysiology and spatial analysis in tracing authenticity and geographical origin of Italian extravirgin olive oils

Authentication and verification of geographical origin of food commodities are relevant topics in the food sector. This study shows the spatial variability in ?13C and ?18O of 387 samples of Italian extra-virgin olive oil (EVOO) collected from 2009 to 2011. EVOOs' ?13C and ?18O values were referred to GIS layers of source water ?18O and climate data (mean monthly temperature and precipitation, elevation, xerothermic index) to evaluate the impact of the most relevant large-scale drivers on Italian EVOOs' isotopic compositions. A geospatial model of ?18O and ?13C for authentication and verification of the geographical origin of EVOOs was developed. The geospatial model resolves EVOOs from four distinct areas: north, south-central Tyrrhenian, central Adriatic and islands, highlighting a zonation of the expected isotopic signatures. Such a geospatial approach appears promising in defining a protocol analysis of EVOOs' isotopic compositions, in order to certify their origin and prevent food frauds. Limits and perspectives of the model are discussed.