Antioxidant activity evaluation of the combination of oregano (Origanum vulgare) and laurel (Laurus nobilis) essential oil as two natural “chain-breaking” antioxidants by direct measurement of sunflower oil oxidation

Antioxidants are commonly used to reduce oxidative damage in lipids, and essential oils offer natural alternatives with antioxidant properties. This research seeks to determine the antioxidant efficiency of the combination of laurel (laurus nobilis) and oregano (origanum vulgare) essential oils exhibiting a chain-breaking mechanism. To this end, an accelerated oxidation of sunflower vegetable oil was carried out at 60 °C for 28 days, in combination with concentrations of 0.05% w/w (1) and 0.02% w/w (2) of the essential oils. BHT at 0.02% w/w was used as a reference antioxidant. The chemical indicators of oxidation (dienes conjugated, peroxides, anisidine and TOTOX values) and volatiles (2-heptenal Z, 2,4-Decadienal EZ and EE) were determined. While no substantial differences were found between the studied concentrations of the essential oils, a decrease in the protective effect was observed when the concentration of laurel was increased. Interestingly, the antioxidant effect of both oregano and laurel essential oils was observed to be similar to that of BHT. The results suggest that the combination of these essential oils with chain-breaking antioxidant mechanisms might be used as an antioxidant in food.