The effect of natural plant extracts on oxidative stabilities of frying oils

Oxidation process is the main contributing cause in deterioration of oils. Consequently, lipid oxidation is a negative reaction that effects of quality of nutritions. Tokoferols are the most important antioxidants in vegetal oils. However, chemical process that implemented to oils cause depreciations in antioxidans. Some reasons as logistic operations, storage actions and vendition process, cause reducing of oxidation stability of oils. Consequently it is an obligation to use natural herbal antioxidants. In this research, 6 different classes of plant extracts and 2 different sentetic antioxidants were added into purified-corn oil which is treated by alumina (Al2O3). After frying treatment, these specimens were taken at exact time ranges that 0, 2, 4, 6 hour and antioxidative effects of plant extracts and sentetic antioxidants were determined and compared with each other by peroxide, dien-trien, DPPH and malondialdehyde analysis. Consequently, it will be worked to state if natural herbal items are antioxidants or not. Key words: Natural antioxidant, plant and spice, antioxidant activity, frying oils, oxidative stability