Composition and antioxidant activity of essential oil of pimento (Pimenta dioica (L) Merr.) from Jamaica

Abstract

The composition and antioxidant activity of the essential oil obtained through hydrodistillation of pimento berry [Pimenta dioica (L.) Merr] samples, namely P1 and P2, sourced from Jamaica, were studied. The chemical composition was analysed by GC and GC-MS methods. The antioxidant activities of the oils were evaluated in terms of their free-radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation and superoxide anion (). Total phenolic content, total reducing power and metal-chelating capacity of the oils were also estimated. Forty-five constituents were identified. The major compound identified was eugenol (74.71%, 73.35%), followed by methyl eugenol (4.08%, 9.54%) and caryophyllene (4.90%, 3.30%). The antioxidant assays showed that the oils possess very high radical scavenging activities (DPPH IC₅₀ 4.82 ± 0.08, 5.14 ± 0.11 µg mL⁻¹, ABTS IC₅₀ 2.27 ± 0.16, 2.94 ± 0.03 µg mL⁻¹, superoxide IC₅₀ 17.78 ± 1.31, 20.65 ± 0.82 µg mL⁻¹). The metal chelating capacities (IC₅₀ 83.62 ± 2.10, 101.77 ± 1.01 µg mL⁻¹) and reducing power were also very high. The results show that the essential oils possess significant antioxidant activity which is comparable to that of pure eugenol. Therefore the oil can be utilised as a natural antioxidant which gives good flavour as well as health benefits.

Keywords:

• pimento
• essential oil
• eugenol
• DPPH
• ABTS assay superoxide scavenging
• metal chelation

Acknowledgement

The authors are thankful to the Director, National Institute for Interdisciplinary Science and Technology (CSIR), India for providing the facilities for carrying out this work.