Characterization of olive paste volatiles to predict the sensory quality of virgin olive oil

One of the main challenges that virgin olive oil producers face today is an accurate prediction of the sensory quality of the final product prior to the milling of the olives. The possibility that olive paste aroma can be used as a predictive measurement of virgin olive oil quality is studied in this paper. The study was centered on distinguishing the aroma of olive pastes that produced virgin olive oils without sensory defects from the aroma of olive pastes the virgin olive oils of which showed sensory defects. Olive pastes were analyzed by solid-phase microextraction-gas chromatography and a sensor system based on metal oxide sensors. Forty-four volatile compounds were identified in olive pastes, all of them being also present in virgin olive oil. Six volatile compounds - acetic acid, octane, methyl benzene, (E)-2-hexenal, hexyl acetate and 3-methyl-1-butanol - distinguished both kinds of pastes with only five misclassified samples. Five metal oxide sensors were able to classify the olive pastes with only two erroneous classifications.