Authentication of Gemlik olive cultivar using 1H NMR spectroscopy and chemometric analysis

In this study, H-1 NMR spectroscopy was used to discriminate Gemlik olives cultivated in a protected designation of origin (PDO) region from those cultivated in non-PDO regions. For this purpose, 95 Gemlik olive samples (47 from PDO and 48 from nonPDO regions) were collected. H-1 NMR spectral analysis was carried out on the oils extracted from these olive samples. The results of the partial least squares-discriminant analysis showed that olives from the PDO and non-PDO regions could be discriminated on the basis of their NMR profiles. The prediction ability of the model was better when olive samples from the district of Mudanya were included in the PDO group. A detailed analysis of the NMR spectra revealed that PDO olives could be discriminated from non-PDO samples mainly due to their higher terpene content. The outcomes of this study clearly indicated that NMR spectroscopy coupled with multivariate statistical analysis has great potential to be used as an objective analytical measure for the discrimination of Gemlik olives cultivated in PDO and non-PDO regions.