The main idea of this work was to study the stability to autoxidation of refined oils with the addition of three essential oils. First, antioxidative activity of the essential oils which are isolated by water distillation from three plants (Thymus Capitatus Hoffmanns, Salvia officinalis L and Rosemarinus officinalis L.), was evaluated by using a β-carotene/linoleic acid system. Peroxidation of the linoleic acid was effectively inhibited by the three essential oils. In fact, they showed strong antioxidative properties when compared to BHT and BHA. Second, the stability to autooxidation of refined oils is evaluated using the Rancimat method. This method provides the induction time for decomposition of hydroperoxydes, produced by fat oxidation. This stability was also evaluated by the determination of the Peroxides Value (PV). As a result, it can be suggested that the stability of refined oils was improved with the addition of the essential oils, which possess antioxidant activities. These findings suggest a potential use of these essential oils as natural preservative ingredient in food industry.
