Cold-pressed vegetable oils: evaluation of polycyclic aromatic hydrocarbons and characteristics of identity and quality

Abstract

The growing market of natural products, stimulated by the interest of consumers in foods that support health promotion, has pushed the food industry to offering novel foods. Among these foods there are cold-pressed vegetable oils, especially safflower, coconut, evening primrose and flaxseed, which are the most available on the market, recognized by preserving bioactive compounds and, some of them, are sources of essential fatty acids. Brazil produces and imports these products, which are marketed with high value and for this reason provide to adulteration with vegetable oils of lesser value. The category of oils and fats presents, among others foods, an important source of exposure to polycyclic aromatic hydrocarbons (PAHs), a group of organic chemical contaminants, some with carcinogenic activity in humans and animals. Objective: Evaluate the cold-pressed vegetable oils for the contamination by PAHs and the parameters of quality and identity, including acidity, peroxide, fatty acids profile and sterols. Methods: The samples will be acquired in São Paulo city market and divided in categories by type of oil: safflower, coconut, evening primrose and flaxseed. PAHs (benzo(a)anthracene, benzo(b)fluoranthene, chrysene and benzo(a)pyrene) will be separated and quantified by high performance liquid chromatography with fluorescence detection, whereas fatty acids and sterols by gas chromatography with flame ionization detector. The acidity and peroxide parameters will be determinate by titrimetric methods. Results will be compared with current legislation of the products and will predict the quality and the levels of contamination of oils marketed. (AU)