Antimicrobial properties of plant essential oils and essences against five important food-borne pathogens

TLDR

The antimicrobial properties of 21 plant essential oils and two essences were investigated against five important food‑borne pathogens, Campylobacter jejuni, Salmonella enteritidis, Escherichia coli, Staphylococcus aureus and Listeria monocytogenes. The study found that bay, cinnamon, clove, and thyme oils were the most potent, with bacteriostatic concentrations ≤0.075% against all five pathogens, while Gram‑positive bacteria were generally more sensitive than Gram‑negative; Campylobacter jejuni was the most resistant, requiring bay or thyme at <1% for bactericidal effect, and Listeria monocytogenes was highly susceptible to nutmeg oil, exhibiting bacteriostatic activity at <0.01% and bactericidal at 0.05% at 35 °C, with higher concentrations needed at 4 °C.

Abstract

The antimicrobial properties of 21 plant essential oils and two essences were investigated against five important food-borne pathogens, Campylobacter jejuni, Salmonella enteritidis, Escherichia coli, Staphylococcus aureus and Listeria monocytogenes. The oils of bay, cinnamon, clove and thyme were the most inhibitory, each having a bacteriostatic concentration of 0.075% or less against all five pathogens. In general, Gram-positive bacteria were more sensitive to inhibition by plant essential oils than the Gram-negative bacteria. Campylobacter jejuni was the most resistant of the bacteria investigated to plant essential oils, with only the oils of bay and thyme having a bacteriocidal concentration of less than 1%. At 35 degrees C, L. monocytogenes was extremely sensitive to the oil of nutmeg. A concentration of less than 0.01% was bacteriostatic and 0.05% was bacteriocidal, but when the temperature was reduced to 4 degrees, the bacteriostatic concentration was increased to 0.5% and the bacteriocidal concentration to greater than 1%.