Chemical Composition and Antioxidant Activity of Clove Essential Oil and its Effect on Stability of Sesame Oil under Accelerated Condition

Abstract

: Recently due to adverse effects of synthetic antioxidants, there has been a growing interest in the application of natural essential oil in vegetable oils. The present study investigated the chemical composition and antioxidant activity of clove essential oil (CEO) and its addition to sesame oil. Methods: composition and antioxidant activity of clove essential oil The CEO was prepared and analyzed by GC-MS. Then, total phenolic content (TPC), antioxidant activity and ferric reducing antioxidant power (FRAP) were determined. The CEO at different concentrations (0.02, 0.04, 0.06, and 0.08%) and TBHQ (0.02%) were added to sesame oil and samples were stored at 60 °C for 5 weeks. Peroxide value (PV), p-Anisidine value (p-AV), total oxidation (TOTOX) value and Thiobarbituric acid reactive substances (TBARs) were determined in sesame oil samples every week for 35 days. A total of 5 components including eugenol (96.25%), eugenol acetate (1.88%), trans-Caryophyllene (1.66%), α-humulene (0.16%), and caryophyllene oxide (0.06%) were determined as the main components of CEO. Results: The TPC of CEO was 345.95±7.85 mg GAE/g. Moreover, the antioxidant activity of CEO for DPPH (IC50) and FRAP methods was estimated 0.83 ± 0.11 mg/ml and 112.37±8.81 mM Fe2SO4. It was shown that peroxide, p-AV, TOTOX, and TBARS values of all sesame oil samples increased during 5 weeks of storage at accelerated conditions. TBHQ showed better function in preventing oil oxidation, but CEO had acceptable function especially in 0.08% concentration. Conclusion: The CEO in vegetable oil due to high phenolic content could retard lipid peroxidation. It could be mentioned that CEO could be considered as an alternative of synthetics ones in vegetable oils.

Keywords

• sesame oil
• clove essential oil
• antioxidant activity
• lipid peroxidation