A novel analytical method to detect adulteration of virgin olive oil by other oils

Abstract  The present study focuses on the olefinic region of the 13C nuclear magnetic resonance (13C NMR) spectrum of virgin olive oil which shows 12 peaks resonating between 127.5 and 130 ppm. These peaks are assigned to the most abundant unsaturated fatty acid moieties of the olive oil, oleic and linoleic acids, which are present in α and β positions of the glycerol backbone. With the use of an internal reference pyrazine, the 12 peaks were integrated and their areas were expressed in mmol/g of virgin olive oil. The intensities of the 12 observed peaks were affected when an authentic virgin olive oil was mixed with a seed oil. This observation was used to develop a semiquantitative method to detect adulteration of virgin olive oil by other oils based on 13C NMR spectroscopy.