Study on stigmastadienes used for extra virgin olive oil adulteration detection

The stigmastadienes used for extra virgin olive oil adulteration detection was investigated. Stigmasta-3, 5-diene content of the extra virgin olive oil blended with different proportion of olive pomace oil, hazelnut oil, sunflower oil, soybean oil, corn oil, peanut oil, rice bran oil, palm oil and walnut oil were detected by highperformance liquid chromatography (HPLC) . Vegetable oil samples were dissolved with petroleum ether, cleaned up with a silica gel column, separated with C30 column and determined by ultraviolet detection at235 nm. Acetonitrile/tert-butyl methyl ether (75∶25, V/V) was served as mobile phase in isocratic elution. The results showed that the method had good recovery and precision, and stigmasta-3, 5-diene was an important characteristic index which could be used for extra virgin olive oil adulteration detection. The proposed method could reliably identify extra virgin olive oil blended with 0.3% olive pomace oil, 0.5% hazelnut oil, 2.1% sunflower oil, 0.5% soybean oil, 0.3% corn oil, 1.5% peanut oil, 0.2% rice bran oil, 0.6% palm oil and 0.6% walnut oil, respectively.