Determination of Camelina Oil Sterol Composition and Its Application for Authenticity Studies

Camelina oil has a high sterol concentration and is rather expensive compared to other vegetable oils. Because of its higher price, it is often adulterated by the addition of other, cheaper oils. This study was performed to validate a method for sterol determination in camelina oil, enabling the detection of camelina oil adulteration. Sterol levels in camelina oil samples were determined by gas chromatography after saponification and solid phase extraction. The method was validated, and the results proved that the chosen method is specific and selective, repeatable and accurate. The quantitatively assessed average contents of sterols in camelina oil samples of Slovenian origin were 21.4 mg 100 g-1 for brassicasterol, 153.6 mg 100 g-1 for campesterol, 3.9 mg 100 g-1 for stigmasterol, and 447.0 mg 100 g-1 for b-sitosterol. Results of camelina oil authenticity studies regarding botanical origin, performed by Principal Component Analysis (PCA) and Regularized Discriminant Analysis (RDA) enabled us to differentiate 100 % camelina oils from camelina oils adulterated with 10 %-40 % added sunflower, rapeseed or soya oil.