Comparative chemometric analysis of fluorescence and near infrared spectroscopies for authenticity confirmation and geographical origin of Argentinean extra virgin olive oils

Extra virgin olive oil (EVOO) is widely used in gastronomy because of its healthy properties, and is a candidate to be adulterated with other vegetable oils to reduce costs. This work shows the results of applying near infrared (NIR) and fluorescence excitation-emission matrix spectroscopies, coupled to chemometric tools, to authenticate and validate the geographic origin of Argentinean EVOO samples. For each spectral data set, principal component analysis (PCA) was applied to both first-order NIR and second-order fluorescence data, partial least squares-discriminant analysis (PLS1-DA) to NIR data, and the multidimensional version of the latter (NPLS-DA) to fluorescence data. The results of the study of sixty EVOO samples of known and unknown registered designation of origin (RDO), as well as artificial samples adulterated with other edible oils, showed that: (1) fluorescence spectroscopy was unable to determine the RDO of all EVOO samples, in contrast to NIR (100% classified correctly), and (2) fluorescence data provide only slightly better results than NIR spectroscopy to detect EVOO adulterations with other vegetable edible oils.