IDENTIFICATION OF ADULTERANTS IN OLIVE OILS

The application of discriminant analysis for identifying and quantifyi ng adulterants in extra virgin olive oils is presented. Three adultera nts were used (sunflower oil, rapeseed oil, and soybean oil) and were present in the range 5-95%. Near-infrared spectroscopy and principal c omponents analysis were used to develop a discriminant analysis equati on that could identify correctly the type of seed oil present in extra virgin olive oil in 90% of cases. Partial least squares analysis was used to develop a calibration equation that could predict the level of adulteration. Cross validation suggested that it was possible to meas ure the level of adulteration to an accuracy of +/- 0.9%. External val idation of the derived calibation equation gave a standard error of pe rformance of +/- 2.77%.