Isoscapes of carbon and oxygen stable isotope compositions in tracing authenticity and geographical origin of Italian extra-virgin olive oils.

The authentication and verification of the geographical origin of food commodities are important topics in the food sector. This study shows the spatial variability in δ 13 C and δ 18 O of 387 samples of Italian extra-virgin olive oil (EVOO) collected from 2009 to 2011. EVOOs’ δ 13 C and δ 18 O values were related to GIS (Geographic Information System) layers of source water δ 18 O and climate data (mean monthly temperature and precipitation, altitude, xerothermic index) to evaluate the impact of the most significant large-scale drivers for the isotopic composition of Italian EVOOs. A geospatial model of δ 18 O and δ 13 C was developed for the authentication and verification of the geographical origin of EVOOs. The geospatial model identified EVOOs from four distinct areas: north, south-central Tyrrhenian, central Adriatic and islands, highlighting the zonation of the expected isotopic signatures. This geospatial approach can be used to define a protocol for analyzing the isotopic composition of EVOOs in order to certify their origin and prevent food fraud. Limits and perspectives of the model are discussed. [ABSTRACT FROM AUTHOR]