Rapid determination of squalene in virgin olive oils using gas-liquid chromatography

Squalene is the most abundant hydrocarbon in virgin olive oil and it is present in variable quantities ranging from 100 to 1,200 mg/100 g of oil. In this study the possibility of simultaneously determining squalene with the GLC analysis of the fatty acids, without separating the unsaponifiable fraction, was confirmed. The proposed method is rapid and is based on the methylation of the oil in alkaline solution and solubilization in isoctane before GLC analysis. The calibration curve was made using the external standard method in peanut oil. The squalene content was determined in 241 virgin olive oil samples from the Molise region, partly from industrial-production and partly extracted in the laboratory from many different olive cultivars. Concentrations of squalene ranged from 90 to 870 mg/100 g of oil and varied considerably in relation to cultivar and olives ripeness.