Multivariate geostatistical analysis of stable isotopes in Portuguese varietal extra virgin olive oils

Stable isotope contents of carbon, hydrogen and oxygen are known to reflect the geo-climatic conditions under which olives grown. This study aims to unravel the correlation between some of the main geographic variables and the isotopic composition of different Portuguese varietal extra virgin olive oil (EVOO) samples. Thus, the isotopic composition (delta C-13, delta O-18 and delta H-2) of 38 EVOO samples from 11 olive varieties from 2 Portuguese regions (Alentejo and Tras-os-Montes) was studied using an elemental analyzer coupled to an isotope ratio mass spectrometry. Multivariate analysis indicated that bulk delta C-13, delta H-2 and delta O-18 values were enough to significantly (P < 0.05) predict altitude, latitude, longitude, temperature, rainfall, and sea distance. This work showed that the assessment of EVOO isotopic composition give information not only on the geographic origin, but also on the environmental conditions. To the best of our knowledge, this is the first report on bulk isotopic composition of Portuguese EVOOs.