DETECTION OF OLIVE OIL ADULTERATION BY MEASURING ITS AUTHENTICITY FACTOR USING REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Addition of as little as 1% of linoleic-rich vegetable oils to olive oil can be detected easily and quantitatively by reversed-phase high-performance liquid chromatography on an octyl-bonded silica stationary phase (Supelcosil-LC 8). The mobile phase was acetone-acetonitrile (70 : 30, v/v), used isocratically. The chromatogram of pure olive oil was compared with those of mixtures of soybean, sunflower and corn oils with olive oil. The results indicate the possibility of the detection of adulteration by less than 1% of linoleic-rich vegetable oils in olive oil qualitatively and quantitatively in less than 15 min. An olive oil authenticity factor was established as a rapid indicator of adulteration and a simple equation for determining the extent of adulteration was derived.