Evaluation of oxidative stability of olive oil

Oil in foodstuff deep frying heated to a long time and effect of some factors (humidity، temperature and oxygen) cause different chemical and physical changes of the oil (such as hydrolysis، oxidation and polymerization) and degrade the quality of the oil and product. The results of these changes increase of the free fatty acids، peroxide value، polar compounds and trans isomers، and also decrease of the unsaturated fatty acids، oxidation induction time، levels of tochopherol and phenolic compounds، which all indicate a decline the oil quality. Studies shows that the chemical composition of oil and especially natural antioxidants are important parameters in predictive the behavior of oil in the frying process. Independently to the commercial category of olive oil، is clearly resistant against the deep frying. In this paper، the oxidative stability of oil during frying according to the source، the presence of natural bioactive compounds (antioxidants) and fatty acid composition have been compared with olive oil