Essential oils as antioxidants: their evaluation by DPPH, ABTS, FRAP, CUPRAC, and β-carotene bleaching methods

Essential oils prevent several chronic diseases owing to the presence of compounds, which have may an important role in the reduction of oxidative stress. Estimation of antioxidant properties of essential oils and evaluation of their antioxidant ability was the aim of this work. The antioxidant properties of essential oils were estimated by DPPH, ABTS, FRAP, CUPRAC, and beta-carotene bleaching methods and related to antioxidant properties of butylated hydroxyanisole and gallic acid. As our results indicate, these essential oils exhibit varying antioxidant activity, however, all of them are able to consume free radicals, to reduce cupric or ferric ions, and to protect or retard the oxidation process of lipids. Most of the essential oils can be applied not only as edible additives to improve the sensory and health promoting properties of foods but also as natural components enhancing the antioxidant stability of foodstuffs to increase their shelf-life.