Analysis of single-cultivar extra virgin olive oils by means of an Electronic Nose and HS-SPME/GUMS methods

The detection of aroma volatile compounds emitted by extra virgin olive oils (EVOOs) is of key importance in the quality control of this product. Physical-chemical techniques (GC, GUMS, HPLC) and sensory analysis (panel test) are the classical methods used for this purpose, but they are expensive, time consuming, and do not allow on-line measurements. In this paper a new device, an Electronic Nose, that is a sensor array based on pure and doped SnO2 sol-gel thin films used for the discrimination of different Mediterranean "single-cultivar" EVOOs, was presented. To confirm the sensor array responses, analytical technique like headspace-solid phase micro-extraction/gas chromatography/mass spectrometry (HS-SPME/GC/MS) analysis was applied to the analysis of volatiles compounds in EVOOs samples. Moreover sensory analysis on EVOOs was carried out. The obtained GC/MS data were used to identify the particular compounds and characterize the chemical composition of the EVOOs samples. In addition a chemometric pattern recognition technique was used for multivariate data analysis. The variations in the GC/MS fingerprint of the different samples were analysed using principal component analysis (PCA). Statistical analyses were carried out on data obtained from Electronic Nose, GC/MS and sensory analysis.