Antioxidant Capacity and Identification of Bioactive Compounds by GC-MS of Essential Oils from Spices, Herbs and Citrus

Background: Essential oils extracted from plant materials are widely studied because of their fungicide and bactericide actions. However, these essential oils also contain compounds with antioxidant activity. Therefore, the antioxidant capacity of essential oils from spices, herbs and citrus was analyzed. Methods: We evaluated the antioxidant activity of the extracts of spices, herbs and citrus essential oils with the aid of in vitro techniques DPPH (2,2-diphenyl-1-picryl-hidrazila), ABTS (2,2`-azino-bis-3- ethylbenzthiazoline-6-sulphonic acid), FRAP (Ferric reducing ability power) and ORAC (Oxygen Radical Absorbance Capacity). For identification of the major compounds present in the essential oils gas chromatography- mass spectrometry (GC-MS) was used. Results: The clove and cinnamon essential oils showed high antioxidant capacity, particularly the essential oil extracted from clove leaves, which showed antioxidant capacity values of 1753.36 and 779.06 µmol TE/g in DPPH and ORAC assays, respectively. The nutmeg and oregano essential oils presented intermediate results. The identification of bioactive compounds was performed in these essential oils by gas chromatography-mass spectrometry. Eugenol and caryophyllene were the main compounds observed in the clove and cinnamon essential oils. The principal component analysis (PCA) confirmed the superiority of the clove and cinnamon essential oils. Conclusion: Therefore, the essential oils extracted from spices proved to be promising sources of antioxidants.