Volatile Olfactory Profiles of Umbrian Extra Virgin Olive Oils and Their Discrimination through MOX Chemical Sensors

Extra virgin olive oil (EVOO) is the best vegetable oil worldwide but, at the same time, isone of the product victims of fraud in the agri-food sector, and the differences about quality withinthe extra-virgin olive oil category are often missed. Several scientific techniques were applied in orderto guarantee the authenticity and quality of this EVOO. In the present study, the volatile compounds(VOCs) by gas chromatography-mass spectrometry with solid-phase micro-extraction detection(GC-MS SPME), organoleptic analysis by the official Slow Food panel and the detection by a SmallSensor System (S3) were applied. Ten EVOOs from Umbria, a central Italian region, were selectedfrom the 2021 Slow Food Italian extra virgin olive oil official guide, which includes hundreds ofhigh-quality olive oils. The results demonstrated the possibility to discriminate the ten EVOOs, evenif they belong to the same Italian region, by all three techniques. The result of GC-MS SPME detectionwas comparable at the discrimination level to the organoleptic test with few exceptions, while the S3was able to better separate some EVOOs, which were not discriminated perfectly by the other twomethods. The correlation analysis performed among and between the three methodologies allowedus to identify 388 strong associations with a p-value less than 0.05. This study has highlighted howmuch the mix of VOCs was different even among few and localized EVOOs. The correlation with thesensor detection, which is faster and chipper compared to the other two techniques, elucidated thesimilarities and discrepancies between the applied methods.