Characterisation of authentic Italian extra-virgin olive oils by stable isotope ratios of C, O and H and mineral composition

The paper shows the isotopic ratios (13C/12C, D/H, 18O/16O) in oil and extracted glycerol and the mineral composition of authentic PDO and PGI Italian extra-virgin olive oils, officially collected from 2000 to 2005 ( N = 539 ) to establish a national databank. 13C/12C and 18O/16O increased from Trentino to Sicily, each year distinguishing Northern Italy from Sicily and Calabria. Significant differences were found among the years and in some cases also between PDOs from the same region. 13C/12C and 18O/16O in bulk oil were significantly correlated with those in glycerol. D/H, measured in 2005 for the first time in oil, showed promising geographical discrimination capability. The content of 26 elements – Li, Rb, Cs, La, Ce and Yb rarely reported in the literature – was measured in well settled 2005 oils after ultrasound acid extraction.