Chemical Composition and Antimicrobial Activity of the Essential Oil of Eugenia caryophyllata Cloves Extracted by Conventional and Microwave Techniques

Abstract

In this present study, we evaluated composition, antimicrobial and antioxidant activity of clove essential oil. Volatile oils of Eugenia caryophyllata were isolated from cloves after cryogrinding by three methods, conventional hydrodistillation (HD), microwave assisted extraction (MAE) and microwave steam distillation (MSD). The results show that the MAE and MSD techniques constitutes the adequate technique for the extraction operations for the yields and the high content in major component and allows minimizing the energy consumption, the heating time and the formation of artefact products. The proposed methods provide more valuable essential oils with high percentage in eugenol what allows to obtain more biologically active essential oils. The MAE and MSD are green technique since reduce environmental burden (less CO2 in the atmosphere). Essential oils from Eugenia caryophyllata were subjected to in vitro antibacterial assay against human pathogenic Escherichia coli, Klelsiella pneumoniae, Enterobacter cloacae, Staphylococcus aureus, Bacillus subtilis, Candida albicans, Fusarium culmorum, and Aspergillus carbonarius using disc diffusion method. The antioxidant properties (2,2-diphenyl-picryl-hydrazyl radical (DPPH)) of essential oil and pure eugenol isolated were examined.