Evaluation of Antimicrobial Properties of Methanolic Extract, Essential Oil and Nanolipozom of Mentha piperita

Natural preservatives that extracted from medicinal plants are the most important bioactive compounds that can be used in foods manufacturing. Generally, useing of these free oils as food preservatives are limited. One way to reduce these limitations is encapsulation of these oils in lipid carriers such as nanoliposomes. The aim of this study was to evaluate the antioxidant and antimicrobial activity of the Mentha piperitas essential oil and methanolic extract. The Extraction of essential oil of Mentha piperita species was performed by steam distillation and its chemical composition were identified using GC and GC-MS. Methanolic extracts were obtained by wet method. Nanoliposomes of Mentha piperitas essential oil was prepared by thin layer hydration and sonication methods. Nanoliposomes particle size was evaluated by using dynamic light scattering and zeta potential was evaluated by using zeta sizer. Also to evaluation the antimicrobial properties, the microdilution method was used. The most predominant constituents were menthol (40.46%), menthone (16.33%), mentho furan (13.37%) and menthyl acetate (7.11%) respectively. Particle size and zeta potential were 98.53 nm and -14 mV respectively and Nanoliposome was stable for 40 days. The minimum inhibitory concentration of essential oils in both free and inside overlap mode on gram-positive bacteria is more than gram-negative bacteria and fungi, while the methanolic extract was disable on gram-negative bacteria and fungi, also had poor inhibitory effect on the gram-positive bacteria. The antimicrobial effect of overlaped essential oil was more than free.