ABSTRACT
In this study, the effect of different concentrations of Zataria multiflora Boiss. essential oil [0.00, 0.005, 0.015, 0.03%], temperatures [8 and 25°C] and storage time [up to 21 days] was evaluated in a food model system [Humburger]. The correlation coefficient of different concentrations of zataria multiflora Boiss.essential oil with logarithm of the numbers of E.coli O[157]:H[7] was [-o.528]. It was found that effect of different concentrations of essential oil on growth rate of E.coli O157:H7 was statistically significant [p<0.05]. The correlation coefficient of storage time and logarithm of the number of microorganism used in this study was [0.434], which indicated a decrease in the growth rate when the storage time was increased. The effect of storage time on growth rate was statistically significant [p<0.05]. In addition the correlation coefficient of storage temperature with logarithm of the number of bacterium was [0.500]. In other words, decreasing the storage temperature [from 25°C to 8°C] resulted in the decrease of the growth rate of the microorganism [p<0.05]