The preservative potential of Amomum tsaoko e ssential oil against E. coil, its antibacterial property and mode of action

Amomum tsaoko is widely distributed in south-west China as a spice. In present study, the antibacterial activity of Amomum tsaoko essential oil (AEO) against foodborne pathogens was evaluated. The antibacterial activity was determined by measuring the zones of inhibition (ZOI), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and the time-kill assay. Results showed the susceptibility of foodborne bacteria Escherichia coli (E. coli) was excellent with the lowest MIC and MBC values of 3.13 and 6.25 mg/mL, respectively. The probable antibacterial mechanism of AEO was the change in permeability and integrity of the cell membranes leading to leakage of nucleic acids and proteins. Detection of the kinetics of E. coli deactivation in situ showed that AEO has good preservative activities in foods. It is necessary to consider that AEO will become a promising antibacterial additive for food preservative.