Triple synergistic essential oils prevent pathogenic and spoilage bacteria growth in the refrigerated chicken breast meat

The synergistic antibacterial activities of shirazi-thyme, cinnamon, and clove essential oils (EOs) in triple combinations investigated in culture medium and chicken breast meat against Escherichia coli, Staphylococ cus aureus, and Pseudomonas fluorescens to reach the minimum concentrations with the highest efficacy. The two and threedimensional checkerboard methods used to determine the interactions of EOs through the Fractional inhibitory concentration index (FICI). P. fluorescens exhibited the highest resistance to EOs, although S. aureus found to be the most sensitive bacterium. The shirazi-thyme with the lowest minimum inhibitory concentration (MIC) was the most active antibacterial essential oil followed by clove and cinnamon. Different double combinations of EOs showed synergistic (FICI <= 0.5) or additive (0.5 < FICI <= 1) effects against P. fluorescens. A triple combination was recorded as synergistic with the 6-8 folds reduction in the MIC, compared to the double-combination and single-use of EOs. The food matrix evaluation confirmed the in vitro results as the triple combination of EOs used at synergistic MICs pre vented the growth of P. fluorescens in refrigerated chicken breast meat for 12 days. Concisely, th e synergis tic antibacterial action of EOs leads to the reduction of adverse effects on the organoleptic properties of food.