Phytosterols as Markers in Identification of the Adulterated Pumpkin Seed Oil with Sunflower Oil

Abstract

In food production, the quality assessment of raw materials and final products is a fundamental parameter for maintaining high quality standards. Pumpkin seed oil is rather expensive compared to other vegetable oils. Therefore, it is often adulterated by the addition of cheaper oils. In contrast to other edible oils, the content of 5-sterols is very low, while 7-sterols are dominating. The aim of this study was to develop a rapid and convenient chromatographic method for authenticity control of pumpkin seed oil using the total sterol profile determined by gas-chromatography (GC) with flame ionization detector (FID). Two pure vegetable oils, pumpkin seed and sunflower oil, processed by minimal technologies (cold pressing) in Romania and an adulterated pumpkin seed oil with 30% of sunflower oil were used as sample matrices in the method development. The determination of 5-sterols, especially -sitosterol has proven to be a good possibility to detect admixture of cheap vegetable oils.