does thyme essential oil (zataria multiflora) improve durability, the taste and nutritional value of doogh?

Introduction: diseases caused by the consumption of bacteria-contaminated foods have been of great importance in public health. therefore, control of dairy product contamination with coliforms is a concern for the durability of dairy producers. control of the contamination by natural products may have dual action; nutritive value and natural antibiotics. in this study, the antimicrobial activity of thyme essential oil against escherichia coli o157: h7 in doogh (iranian fermented dairy drink) was examined and the mic and mbc were determined. methods: antimicrobial activity of thyme essential oil was examined using different concentrations (0, 30, 60, 90, and 120 μl/ml) against bacteria with a density of 105cfu/ml during the 60-day at 4 °c. moreover, the effect of different concentrations of essential oils on the taste of doogh was also studied. taste evaluation was performed based on 5 points hedonic test to evaluate the effect of thyme oil on the sense of taste. duncan software was used to determine the difference between test and control groups at a confidence level of 5%. the spss software was also used for statistical analysis. results: all concentrations of thyme essential oil could stop the growth of bacteria (p<0.05). the inhibitory effect of oil increased with increasing concentration and time. based on the results of sensory (taste) evaluation, treatment 2 (containing 60 μl/ml of essential oil of thyme) was selected as the best treatment. conclusion: thyme essential oil can be used as a natural preservative with a positive impact on taste and nutritive value.