A green sorptive extraction method (HiSorb-TD-GC-MS) for determining the extra virgin olive oil (EVOO) aroma profile

Abstract

A headspace high sorptive extraction (HS-HiSorb) Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS) method was developed and optimized for the determination of the volatile profile of extra virgin olive oil (EVOO). The HS-HiSorb extraction parameters of temperature, sample mass, stirring rate, and adsorption time were optimized by applying the one-factor-at-a-time (OFAT) approach. A total of 21 multi-varietal olive oil samples were collected from four different olive mills in Cyprus during the harvesting period 2020-2021. Seventy-six volatile organic compounds (VOCs) were identified and semi-quantified, belonging to several chemical categories such as hydrocarbons (31) three of which are terpenes, aldehydes (22), carboxylic acids (6), ketones (5), esters (4), alcohols (3), ethers (2), furans (2), and others (1). Aldehydes (40.20%) and hydrocarbons (41.08%) represented the main components of olive oil's volatile profile. The overall concentrations of VOCs in the samples ranged from 8.73 to 39.81mg/kg. The HiSorb-TD-GC-MS method was evaluated in terms of repeatability and linearity for selected VOCs. Repeatability was performed at three different concentrations (1, 10, and 100ppbv), and the relative standard deviation (RSD) ranged from 2.21 to 15.86%. The calibration curves of (E)-2-hexenal, 1-penten-3-one, nonanal, and hexanal were developed to evaluate the linearity range. The results were satisfactory, with the correlation coefficient (R2) greater than 0.98. Finally, the limitations of the method are mentioned and discussed.