A preliminary study on the potential of front face fluorescence spectroscopy for the discrimination of Moroccan virgin olive oils and the prediction of their quality

Abstract

This study examines the feasibility of using front face fluorescence spectroscopy (FFFS) to authenticate 41 virgin olive oil (VOO) specimens collected from 5 regions in Morocco (Fez/Meknes, Eastern, Northern, Beni-Mellal/Khenifra, and Marrakech/Safi) during 2 consecutive crop seasons (2015–2016 and 2016–2017). By jointly applying factorial discriminant analysis (FDA) to the emission spectra acquired after excitation at 270, 290, and 430 nm, clear discrimination between VOOs according to their geographic origin (96.72% correct classification) and variety (95.12% correct classification) was observed. This trend was confirmed following the application of partial least squares regression (PLSR) to the fluorescence spectra, where excellent prediction of free acidity (R² = 0.98) and peroxide (R² = 0.96) values and good prediction of k₂₃₂ (R² = 0.88), k₂₇₀ (R² = 0.88), and chlorophyll content (R² = 0.89) values were observed.