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

• Main Authors: seyedmahmoud miri, asghar tarmian, Mohammad Azadfallah Azadfallah, Ali Abdolkhani, Davod Efhami Sissi
• Format: Article
• Language: fas
• Published: Iranian Scientific Association of Wood and Paper Industries 2018-02-01
• Series: Iranian Journal of Wood and Paper Industries
• Subjects: Aspergillus mold; Controlled release; Essential oil; Microencapsulation; Poly (methyl methacrylate)
• Online Access: http://www.ijwp.ir/article_25657_0d98fc24aa0baeac3a2680a8395d5f80.pdf

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.