Authentication and quantitation of frauds in extra virgin olive oils based on HPLC-UV fingerprinting and multiariate calibration

Abstract

HPLC-UV fingerprinting, obtained on a Zorbax Eclipse XDB-C8 reversed-phase column under gradient elution employing 0.1% formic acid aqueous solution and methanol as mobile phase, was applied to the analysis and characterization of olive oils. More than 130 edible oils, including monovarietal extra-virgin olive oils (EVOOs) and other vegetable oils, were analyzed. Principal component analysis results showed a noticeable discrimination between olive oils and other vegetable oils from raw HPLC-UV chromatographic profiles as data descriptors. In contrast, selected HPLC-UV chromatographic time-window segments were necessary to achieve discrimination among monovarietal EVOOs. Partial least square (PLS) regression was employed to tackle olive oil authentication of an Arbequina EVOO adulterated with a Picual EVOO, a refined olive oil, and a sunflower oil. Highly satisfactory results were obtained after PLS analysis, with overall errors in the quantitation of adulterations of an Arbequina EVOO (down to 2.5% adulterant) below 2.9%.