Varietal authentication of virgin olive oil: Proving the efficiency of sesquiterpene fingerprinting for Mediterranean Arbequina oils

Abstract

Virgin olive oil (VOO) is a highly appreciated product fundamental in the Mediterranean diet. Since its sensory attributes are greatly influenced by the olive cultivar, the varietal authentication of VOOs is needed to protect consumers from misleading information. The present study aims to evaluate the suitability of sesquiterpene hydrocarbon (SH) fingerprint as VOO cultivar marker beyond geographical, agronomical and processing conditions. The study was mainly focused on Mediterranean Arbequina oils. SH profile of more than 400 VOOs from 6 counties and 38 different cultivars and coupages was analysed by Headspace Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS). Partial Least Square-Discriminant Analysis (PLS-DA) classification models were built with the aligned chromatograms. A binary PLS-DA model was built to distinguish 'Arbequina' oils from those of other cultivars (non-'Arbequina' class) and it was externally validated. The results of the external validation showed a 95.1% of overall correct classification confirming the suitability of SH fingerprint as a screening method for the authentication of Arbequina VOO. Also, the discrimination capacity of SH fingerprinting to authenticate VOOs from other cultivars was preliminary explored and promising results were obtained.