Cultivar discrimination, fatty acid profile and carotenoid characterization of monovarietal olive oils by Raman spectroscopy at a single glance

Monovarietal extra virgin olive oils (EVOOs) from Olea europea trees grown in the same experimental orchard have been characterized by Raman spectroscopy combined with chemometrics. Linear discriminant analysis of the EVOO Raman spectra correctly classified up to 94.4% of samples, as a function of the cultivar, at four different maturation stages. The sensitivity of Raman spectroscopy to the oil cultivar is due to the genotypic dependence of the olive oil composition in terms of both carotenoid and fatty acids. Thus, using gas chromatography as the reference technique, models for predicting the oleic, palmitic and linoleic acid content are obtained combining Raman spectra and partial least squares regression analysis. Evidences that a similar approach could be implemented also for carotenoid characterization are provided.