ABSTRACT
The growing interest in substitution of chemical food preservatives by naturalones has fostered researchs on plantessentiak oils and extracts. In this study effect of different concentrations of Zataria multiflora Boiss. Essential oil [0, 0.005, 0.015 and 0.03%] on Bacillus cereus ATCC 11778, [10[3]cfu /ml], was evaluated using sterilized samples [16 bottles containing 80 ml barley soup] and 4 different incubating temperatures [8, 10, 15 and 25°C] during 21 days. Data analysis was done using two way ANOVA. It was found that effect of different concentrations of essential oil on growth rate of Bacillus cereus ATCC 11778 was statistically significant [p<0.01]. The results suggested that Zataria multiflora Boiss. essential oil can be considered as a natural preservative in some foods
Subject(s)
Oils, Volatile , Hordeum , Plant ExtractsABSTRACT
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]