Objective: To evaluate the effectiveness of some plant essential oils on E.coli and Saureus.
Design: Interventional study and obtain the effective concentration of each essential oils.
Materials: Essential oils of Pennyroyal (Mentha pullegium), Peppermint (Mentha piperUa), Tarragon (Artemisia dracunculus), Caraway seed (Carum catVi) and Thyme (Thymus volgaris). E.coli k12: Department of microbiology university of Bristol. S.aureus RTcc 1907: Razi Institute.
Procedure: 1- Induce the varius concentration of each essential oils in broth medium. 2- In tradition of 106 bacterial of medium. 3- Incubate over night at 37 °c. 4- Check the tubes for growth of bacteria. 5- Subculture in agar medium and incubate over night at 37°c. 6- Check the plate for bacterial colonies.
Results: The results showed that the volatile oils of the thyme was the most effective oil, thus the MIC and MBC of this oil on
E.coli were 0.1%, 0.15% and on Saureus were 0.05%, 0.1% respectively. The oils of peppermint, pennyroyal and caraway seed had moderate effect while the volatile oils of Tarragon had the minimum effect on tested-bacteria.
Implication: As the results showed, all of the essential oils have antimicrobial activity, thus it is possible that use these oils as a natural flavouring and preservative in foods. J. Fac. Vet. Med Univ. Tehran. 57, 4: 81-83, 2002.