Chemical composition, antioxidative‎, antibacterial‎‎, and time-kill activities of some selected plant essential oils against foodborne pathogenic and spoilage organisms.

Abstract

Essential oils (EOs) 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; and 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, minimum bactericidal concentration, and time-kill methods were used to determine the antibacterial ‎‎activity of EOs. The antioxidative ‎ activity of EOs were determined by 2, 20-diphenyl-1-picrylhydrazyl radical scavenging and ferric reducing antioxidative ‎ power methods. All EOs exhibited antibacterial ‎‎activity, however, Z. multiflora EO was the most effective followed by O. vulgare EO. The lowest antibacterial‎‎‎‎‎ activity was observed in C. verum EO. The most sensitive among tested bacteria to Z. multiflora and O. vulgare EOs was E. coli O157:H7 and to S. aromaticum; and C. verum EOs were S. putrefaciens and P. fluorescens, respectively. Z. multiflora and O. vulgare EOs were able to kill 85.00% and 80.00% of the E. coli O157: H7 and S. putrefaciens cells in 4 hr, respectively. The highest antioxidative ‎activity was observed in Z. multiflora EO. The tested EOs showed the highest antioxidative ‎activity at a concentration of 2.00 g L-1. Ferric reducing antioxidant power value of Z. multiflora, O. vulgare, S. aromaticum and C. 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 a decrease in antioxidative ‎ activity.