DETECTION OF OLIVE OIL ADULTERATION WITH RAPESEED AND SUNFLOWER OILS USING MOS ELECTRONIC NOSE AND SMPE-MS

The study analyzed the effectiveness of two types of electronic nose systems to detect adulteration of extra virgin olive oil (EVOO) with rapeseed and sunflower oils. Tested methods included volatile analysis with the electronic nose based on MOS sensors (HS-E nose) and by direct coupling of SPME to MS (SPME-MS). Volatile compounds were analyzed also by SPME-GC/MS. Samples of EVOO were mixed with different proportions, ranging from 5 to 50% (v/v), of seed oils and fingerprints of volatile profiles of all samples were generated. In order to obtain as much chemical information as possible and to find a volatile marker to detect adulterations of EVOO with seed oils, principal component analysis (PCA) and partial least squares (PLS) analyses were applied to the data. The application of PCA and PLS analyses to the data from two electronic noses and SMPE-GC/MS were sufficient to differentiate the adulterated samples from pure EVOO. Excellent results were obtained in the prediction of the percentage of adulteration by PLS analysis. SPME-GC-MS analysis with subsequent PCA yielded good results; however, it was time-consuming. The two electronic noses, with subsequent PCA treatment of data, offering the advantages of rapidity and reliability, enabled detection of olive oil adulteration with different contents of seed oils.