Characterization of Italian extra virgin olive oils using 1H-NMR spectroscopy

High-field (600-MHz) proton nuclear magnetic resonance (H-1-NMR) spectroscopy was applied to the analysis of 55 extra virgin olive oil samples from four Italian regions (Campania, Lazio, Sicily, and Umbria) and obtained from different olive varieties. The multivariate statistical analysis (PCA, hierarchical clustering) performed on the normalized intensities of H-1-NMR resonances due to minor components (beta-sitosterol, n-alkenals, trans-2-alkenals, and other volatile compounds) allows a good classification of oil samples obtained from traditional varieties with respect to the region of origin (96% of oils correctly classified). Samples obtained from one new experimental cultivar (FS-17) were not correctly classified, indicating a strong contribution of olive variety on the chemical composition of virgin olive oils. The potential contribution and limits of NMR in the authentication of virgin olive oil geographical origin and variety are discussed.