Antibacterial activity of clove essential oil against food-borne pathogenic bacteria

Abstract

INTRODUCTION: Food infection and intoxication are still a major problem worldwide, in spite of the modern methods used to preserve food. Application of synthetic preservatives may lead to negative health consequences and growing public interest is now focussing toward discovery of novel substances from natural sources which will be safer and without any side effects. Among natural antimicrobial agents, spices could be promising alternative to synthetic additives, since at the same time they enhance aroma and flavour and control food-borne pathogens and spoilage bacteria in processed foods. Clove (Syzygium aromaticum) is aromatic spice commonly used in the cuisine of Asian, African, and the Near and Middle East countries. It has many biological properties which mainly derived from high level of eugenol (72-90%) in its essential oil. AIM: The purpose of this study was to evaluate antibacterial activity of commercial clove essential oil against a range of food-born pathogenic bacteria such as Escherichia coli, Salmonella enteritidis, Shigella sonnei, Staphylococcus aureus, Listeria monocytogenes and Bacillus cereus. METHODS USED: Antibacterial activity of clove oil and its dilution was determined by agar well diffusion method and the diameters of clear inhibition zones around the wells were measured. For minimal inhibitory concentration (MIC) is taken the lowest dilution of the clove essential oil that caused a diameter of inhibition zone of 1mm. RESULT: The results of the agar well diffusion test showed that the clove essential oil possessed strong antibacterial activity against all bacteria species tested with zones of inhibition ranging from 16 to 23 mm. The slightly higher antibacterial activity was noticed against Gram-negative bacteria (MIC 1,5% v/v) as compared to Gram-positive bacteria (MIC 3% v/v). CONCLUSION: Clove essential oil could be a potentially source of novel antibacterial compounds against food-borne pathogenic and spoilage bacteria, alone or in combination with other preservation methods.