Introducing a 4D-metabolomics approach in extra virgin olive oil authenticity study

Extra virgin olive oil (EVOO) has been recognized as food of high nutritional value, with many of its health properties derived from the fraction of phenolic compounds (PCs). Special attention has been paid to secoiridoids, compounds that contribute significantly in EVOOs related health claim (EU 432/2012), due to their high concentration levels in EVOOs. Secoiridoids subclass comprises a number of isomers. Their separation and identification are challenging and not always possible with the high-resolution mass spectrometry (HRMS) -based methodologies applied so far, as they may pose identical chromatographic and spectral profiles.

In the present research work, a novel methodology utilizing Trapped Ion Mobility Spectrometry (TIMS) incorporated in Liquid Chromatography (LC)-HRMS workflows is being implemented and applied in olive oil, in order to separate and identify isomers detected on the phenolic fraction. TIMS introduces an additional, orthogonal dimension, that of ion mobility, which combined with HRMS-workflows increases the analytical depth-of-coverage and facilitates identification of isomers. Both targeted and untargeted approaches have been exploited, taking advantage of overall information retrieved from LC-TIMS-HRMS analysis. Integrated data treatment workflows in combination with chemometrics have also been applied, providing excellent analytical performance and prediction ability. Finally, noteworthy results are retrieved in olive oil samples derived from different variety and geographical origin, highlighting isomers as important authenticity markers.

Presenter: Sofia K. Drakopoulou, Ph.D. (Candidate, National & Kapodistrian, University of Athens, Greece)