DETERMINATION OF ANTIMICROBIAL EFFECTS OF NISIN AND MENTHA SPICATA ESSENTIAL OIL AGAINST SALMONELLA TYPHIMURIUM UNDER VARIOUS CONDITIONS

Background and Aim:Plant essential oils and nisin have been known as antimicrobial agents that could be used to control food-borne pathogenic bacteria such as Salmonella Typhimurium. The aim of this study was to evaluate the antimicrobial efficacies of nisin and Mentha spicata essential oil (EO) both separately and in combination, against S. Typhimurium at different temperatures (4, 9 and 14°C), pH (5, 6 and 7) and NaCl concentrations (0, 1, 2 and 4%).Methods:The chemical components of EO were analyzed by gas chromatography-mass spectrometry (GC-MS). The minimum inhibitory concentrations (MIC) of nisin and EO were assessed using a broth micro-dilution method. For combinations of the antimicrobials, the Differences in Population assay were used to determinate their effects.Results:The dominant active components of EO were carvone (78.76%) and limonene (11.50%). The EO MIC value was 80 μl/ml, but nisin did not inhibit the growth of S. Typhimurium. The susceptibility of S. Typhimurium to nisin and EO was found to enhance with increasing incubation temperature, pH and NaCl concentration.Conclusion:Our findings demonstrate that a combination of nisin and Mentha spicata essential oil might be a potential source of preservative for the control of S. Typhimurium in the food industry.

کلیدواژه ها:

Mentha spicata essential oil ، Nisin ، Salmonella Typhimurium