Potencial antioxidante dos extratos de manjericão (Ocimum basilicum Lamiaceae) e orégano (origanum vulgare Lamiaceae) em óleo de soja

Abstract

This study aimed to evaluate the antioxidant potential of basil (Ocimum basilicum L.) and oregano (Origanum vulgare L.) extracts and to measure the oxidative stability of soybean oil added to both extracts. Basil and oregano extracts were obtained in fresh and dry forms from the leaves of spices subjected to aqueous, ethanol and sequential extraction for 30 min at a ratio of 1:3 (m/m, spice:solvent) and continuously shaken at room temperature. For the extracts, the value of effective concentration (EC50), the maximum antioxidant activity (AA) and the amount of total phenolic compounds (TFC) were obtained. The oregano and basil extracts that had higher antioxidant activity were applied to soybean oil at concentrations ranging from 250 to 2,000 mg kg-1, to evaluate the oxidative stability. The results indicated that the ethanol extracts of fresh basil with EC50 = 863.97 mg mL-1, AA = 35.63% and TFC = 56.55 mg g-1 and dry oregano with EC50 = 415.82 mg mL-1, AA = 48.42% and TFC = 147.96 mg g-1 were more efficient for application in soybean oil at a concentration of 2,000 mg kg-1, which showed the highest oxidative stability, 21.8 and 15.1 hours, respectively. Based on the employed methodology and under the studied conditions, it was concluded that the ethanol extracts of fresh basil and dry oregano showed antioxidant potential when applied in soybean oil.