JOURNAL OF COSMETIC SCIENCE 402 table via easy calculations (percentage of the chemical component multiplied by the values of the different kinds of antioxidant activity), to obtain the antioxidant activity of each essential oil. CONCLUSION This study examined the antioxidant activities and major chemical components of twenty- fi ve commonly used essential oils using the DFRS, TPC, TEAC, and FTC assays. Eugenol, of the essential oil cinnamon bark extra, yielded the best DFRS assay values. Carvacrol, of the essential oil ajowan, showed the best results from the TPC and TEAC assays. Thymol, of the essential oil oregano, showed the strongest inhibition of linoleic acid peroxidation via the FTC assay. Those components with high phenolic contents revealed great anti- oxidation properties and contained a positive correlation with the DFRS, TPC, TEAC, and FTC assays. Our research shows that cinnamon bark extra, ajowan, and oregano es- sential oils have the potential to be developed into antioxidant ingredients for functional foods and cosmetic products. ACKNOWLEDGMENTS We thank the National Science Council of Taiwan, the Republic of China, for support (NSC98-2113-M-241-001-MY2-1). We also thank Prof. R. G. Finke and Dr. J. E. Mondloch for helpful discussions. REFERENCES (1) L. I. Daise, D. S. Alviano, C. S. Alviano, and P. P. Kolodziejczyk, Screening of chemical composition, antimicrobial and antioxidant activities of Artemisia essential oils, Phytochemistry, 69, 1732–1738 (2008). (2) M. R. Loizzo, F. Menichini, F. Conforti, R. Tundis, M. Bonesi, A. M. Saab, G. A. Statti, B. Cindio, P. J. Houghton, F. Menichini, and N.G. Frega, Chemical analysis, antioxidant, antiinfl ammatory and anticholinesterase activities of Origanum ehrenbergii Boiss and Origanum Syriacum L. essential oils, Food Chem., 117, 174–180 (2009). Figure 4. Inhibition of linoleic acid peroxidation of the FTC assay from four major chemical components of oregano compared with its essential oil at a concentration of 1 mg ml−1.

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