Microencapsulation of Zataria multiflora thyme essential oil to improve its antifungal efficiency by controlled release mechanism

Document Type : Research Paper

Authors

1 Ph.D. student, Department of wood and paper science & technology, Faculty of natural resources, University of Tehran, Karaj, Iran

2 Associate prof., Department of wood and paper science & technology, Faculty of natural resources, University of Tehran, Karaj, Iran

3 Assistant prof., Department of wood and paper science & technology, Faculty of natural resources, University of Tehran, Karaj, Iran

Abstract

The purpose of the present research is enhancing the thyme essential oil efficacy by microencapsulation technique with emphasis on controlled released mechanism. First, essential oil was extracted by hydro-distillation in a Clevenger-type apparatus for 4 h. Then, core-shell microcapsules were prepared using solvent evaporation method with oil in water emulsion system. To measure the efficacy of encapsulated thyme oil, UV-visible spectrometer was used and was found to be 67 percent. The size and shape of oil droplets in emulsion were observed with optical microscope and the morphology of the polymer capsules was observed with scanning electron microscope. Release kinetics in both free and encapsulated forms showed that all components of free oil evaporated into atmosphere, while just 6 percent of capsules evaporated in the same condition. So, microencapsulation method increased the efficacy of the essential oil with controlled release mechanism. Filter paper disk test was performed to investigate the fungicide effects of thyme oil in both free and capsulated forms before and after leaching test. Results revealed that there are no significant differences between control samples and those treated by free oil especially after leaching test. In contrast, the samples treated by microencapsulated thyme oil showed much more resistance against Aspergillusniger mold indicating that the controlled release mechanism can prevent mold growth on filter paper disk and therefore improved the oil efficacy.

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[1] Teeka, P., Chaiyasat, A. and Chaiyasat, P., 2014. Preperation of Poly (methyl methacrylate) microcapsule with encapsulated Jasmin oil. Procedia Engineering, 56: 181-186.
 [2] Kaul, O., Walia, S. and Dhaliwal, G.S., 2008. Essential oils as green pesticides: potential and constraints. Biopesticides international Indian journal, 4(1):63-84.
[3] Tarmian, A., 2017. Measurement of Fiber Saturation Point of Wood Using Differential Scanning Calorimetry: Measurement Fundamentals and Experimental Results. Iranian Journal of wood and paper industries, 7(4):615-623. (In Persian).
[4] Ghosh, K.S. 2006. Functional Coating by Polymer Microencapsulation. Wiley-VHC Verlag GM bH & Co, Weinheim, Denmark, 371 p.
[5] Benita, S., 1996. Microencapsulation: Methods and Industrial applications. Marcel Dekker, New York, 784 p.
[6] Hong, K. and Park, S., 2000. Preparation of poly (l-lactic) microcapsules for fragrant fiber and their characteristics. Polymer journal, 41:4567-4572.
[7] Byun, y., Hwang, B., Bang, S.H., Darby, D., Cooksey, K. and Dawson, P.L., 2011. Formulation and characterization of а-tocopherol loaded poly caprolactone (pcl) nanoparticles. Food Science and Technology, 44:24-28.
[8] Pena, B., Mamuye, A. and Gumi, T., 2012. PSF/Vanillin capsules for Textile Application. Procedia Engineering, 44: 1331-1332.
[9]  Panek, M., Peinprecht, L. and Hulla, M., 2014. Ten Essential Oils for Beech Wood Protection-Efficacy Against Wood-destroying Fungi and Moulds, and Effect of Wood Discoloration, Bioresources.com, 9(3), 5588-5603.
[10] Souza, M., Caldas, L., Tohidi, D. and Molina, J., 2014. Properties and controlled release of Chitosan microencapsulated Limonene oil. Revista Brasileira Farmacognosia, 24: 691-698.
[11] Nikola, J., 2014. Microcapsule-protected actives reduce leaching. European coatings journal, 4:36-40.
]12] Vonica, B., Kreft, O., Kokol, V. and Chen, W.T., 2009. Encapsulation of Rosemary Oil in Ethylcellulose Microcapsules. Textile and Polymer Journal, 1(1): 13-19.
[13] Standard test method for determining the resistance of paint films and related coatings to fungal defacement by accelerated four-week agar plate assay, ASTM standard, D 5590, 2000