Revisiting 3D van Krevelen diagrams as a tool for the visualization of volatile profile of varietal olive oils from Alentejo region, Portugal.

This paper aims to study the volatile composition of monovarietal extra-virgin olive oils from different varieties from Alentejo region (Portugal). Volatile profile of 82 olive oils was performed by head-space solid phase micro-extraction hyphenated with gas chromatography/mass spectrometry (HS-SPME-GC/MS). A total of 107 volatile compounds, belonging to several class of compounds, like aldehydes, hydrocarbons, alcohols, terpenoids, ketones, sulphurous compounds, acids and esters were identified, assigned to a specific biogenic origin and total abundances were plotted in modified 3D van Krevelen diagrams. The 3D plots showed that there are compositional differences among olive oil varieties. Discriminant analysis confirmed that the pattern of volatile compounds includes enough information to group sample variety amongst discrete monovarietal olive oil. Combining statistical analysis (t-Student) and graphical-tools (van Krevelen diagram) seems to be a powerful tool to determine what molecular families were characteristic of each olive oil variety, contributing to the valorization of monovarietal Portuguese olive oil.