found a reduction of 42.86 and 21.71% in the levels of polyunsaturated fatty acids in olive and sunflower oils, respectively, after 15 h of frying. The decrease in linolenic and a-linolenic acids may represent a loss of nutritional value, because they are essential fatty acids and are not synthesized by the human body. The results regarding stearic, arachidic, behenic and
eicosenoic fatty acids showed that they remained virtually unchanged in most samples. Palmitic and oleic acids (22.5%) and RE (16.83%). The data showed that there was no synergistic effect between rosemary extract and TBHQ.