Antilisterial effect of Mentha spicata in the presence of temperature, pH and NaCl

Listeria monocytogenes is an important food-borne pathogen and its control in foods is a significant challenge. This study evaluated the effectiveness of Mentha spicata essential oil on limitingL. monocytogenes growth at different temperatures (4, 9 and 14°C), pH (5, 6 and 7) and NaCl concentrations (0, 1, 2 and 4 g/100mL). Chemical constituents of the M. spicata essential oil were identified by gas chromatography/mass spectrometry (GC/MS). The susceptibility of bacterium was performed by the minimal inhibitory concentration (MIC) using the micro-broth dilution technique. The major detected components were carvone (78.76%), limonene (11.50%) and menthol (1%). The MIC value of essential oil was 160µl/mL. The results obtained showed that the effectiveness of M. spicata was pronounced by increasing of salt and temperature and decreasing pH. In conclusion, the encouraging results indicated that the essential oil of M. spicata might be exploited as natural preservative for the control of L. monocytogenes.