Antioxidative activity of extracts from selected species of the family Lamiaceae in sunflower oil

The kinetics of peroxide accumulation during oxidation of sunflower oil at 100 °C in the presence of different concentrations of hexane, ethyl acetate and ethanol extracts of Melissa officinalis L., Mentha piperita L., Mentha spicata L., Ocimum basilicum L., Origanum vulgare L. and Saturejae hortensis L. have been studied. It has been established that the extracts from Ocimum basilicum L. and Origanum vulgare L. do not improve the oxidation stability of sunflower oil. The ethanol extracts from the other four spices have proved to be the most active in retarding the autoxidation process. The strongest action has been exhibited by the ethanol extracts from Saturejae hortensis L., followed by the ethanol extracts from Mentha piperita L. and Melissa officinalis L. The stabilization factor F for the ethanol extracts (0.1–0.5%) from Saturejae hortensis L. is 1.8–2.3. It is higher than F for 0.02% butylated hydroxytoluene BHT (F = 1.2). From a practical point of view (yield and stabilization factor), the direct ethanol extract from Saturejae hortensis L. should be recommended as the most suitable antioxidant for the stabilization of sunflower oil.