Document Type: Original Article
Department of Food Hygiene and Aquaculture, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
Department of Food Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
Essential oils have been utilized as a growth inhibitor of microorganisms. This study was aimed to recognize the composition, antioxidative, antibacterial and time-kill activities of Origanum vulgare, Zataria multiflora, Syzygium aromaticum, Cinnamomum verum EOs against Listeria monocytogenes, Escherichia coli O157:H7, Shewanella putrefaciens and Pseudomonas fluorescens. Gas chromatography-Mass Spectrometry was used to determine the chemical composition of EOs. Disc diffusion, Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and time-kill methods were used to determine the antimicrobial activity of EOs. Antioxidative activity of EOs were determined by DPPH radical scavenging and ferric reducing antioxidative power methods. All EOs exhibited antimicrobial activity, however Zataria multiflora EO was the most effective (MIC ≤ 1.28 mg ml-1) followed by Origanum vulgare EO. The lowest antibacterial activity was observed in Cinnamomum verum EO. The most sensitive among tested bacteria to Zataria multiflora and Origanum vulgare EO was Escherichia coli O157:H7 and about Syzygium aromaticum, Cinnamomum verum EOs were Shewanella putrefaciens and Pseudomonas fluorescens. Zataria multiflora and Origanum vulgare EOs were able to kill 85% and 80% of the E. coli O157: H7 and Shewanella putrefaciens cells in 4 h, respectively. The highest antioxidative activity was observed in Zataria multiflora EO. The tested EOs showed the highest antioxidative activity at a concentration of 2 g L-1. Ferric Reducing Antioxidant Power value of Zataria multiflora, Origanum vulgare, Syzygium aromaticum and Cinnamomum verum was 2.01 ± 0.03, 1.47 ± 0.04, 1.01 ± 0.03 and 0.66 ± 0.34 respectively. High concentrations of tested EOs showed decrease in antioxidative activity.