Abstract:The antibacterial activity of 12 plant essential oils, including Syringa oblata Lindl, against prevalent foodborne pathogens such as Escherichia coli(E. coli), Staphylococcus aureus and Salmonella, was assessed by the hole punching method and serial dilution method to determine the inhibitory zone, minimum inhibitory concentration(MIC) and minimum bactericidal concentration (MBC). Essential oils with strong antibacterial activity were selected for compounding, and synergistic indices (SI) were investigated using serial dilution method. One of the formulated essential oils was selected to preserve fresh chicken breast. The total number of colony, and the counts of E. coli, Staphylococcus aureus, and Salmonella, as well as the flavor profiles were examined as indicators. The results indicated that the inhibitory zone diameters of 12 plant essential oils against three pathogens ranged from 0.3 to 7.3 cm, with MIC ranging from 0.98 to 125 g/L, and MBC from 3.91 to 500 g/L. Four pairs of essential oils were screened, resulting in four synergistic combinations that showed enhanced antibacterial activity against E. coli, S. aureus and Salmonella, and their lowest SI values were 0.750, 0.375 and 0.375, respectively. Notably, the combination of oregano and pine needle essential oil significantly inhibited the proliferation of the total bacterial colonies, E. coli and Salmonella of chicken breast during cold storage, extending its shelf life by 5 days. The screened plant essential oils displayed good inhibitory activity against foodborne pathogens, and the combinations exhibited synergistic enhancement in effective MIC reduction. Specifically, the oregano and pine needle essential oil combination demonstrated efficacy in preserving chilled chicken breast, highlighting its potential for natural food preservative development.
