Quality criteria, chemical composition and antimicrobial activity of the essential oil of Ehrh.

The aim of the present study is the valorization of the essential oil of Ehrh. The research plan and methods included 3-axis: the first axis consists of studying the organoleptic and physicochemical characterization of the essential oil, the second is the chemical analysis carried out by Gas Chromatography/Mass Spectrometry (GC/MS) and the third consists of evaluating its antimicrobial activity against selected microorganisms. The results obtained for the organoleptic and physicochemical properties are as follows: appearance: Liquid, mobile and clear, odor: Strong odor characteristic of Ehrh, color: Pale yellow; relative density (0.92), miscibility with ethanol (1V/2V), freezing point (T < -10 °C), refractive index (1.5256), rotating power (+0.825), acid index (1.68), ester index (68.44), saponification index (70.13) and iodine index (12.05).Chemical analysis identified 69 compounds which are mostly oxygenated monoterpenes such as piperitenone oxide (32.55%), pulegone (10.14%), piperitone oxide (8.34%), etc. The microbiological tests were carried out by an agar diffusion test using the essential oil of Ehrh. The microbiological tests were carried out by a diffusion test on agar, these tests are carried out on six microbial strains (five bacteria and one yeast).The inhibitory effect of our oil is well marked against bacteria: (17.50 ± 0.70 mm at 50 μL/mL), (17.00 ± 1.00 mm at 50 μL/mL) and (16.33 ± 0.57 mm at 50 μL/mL) while it was moderate against (14.33 ± 1.15 mm at 50 μL/mL) and spp (13.00 ± 0.00 mm at 50 μL/mL) as well as against yeast, (15.33 ± 1.52 mm at 50 μL/mL). It appears from these results that our oil is of high quality and can be used in several areas. The results obtained are therefore promising and thus open the way for manufacturers to use this essential oil of Ehrh in the pharmaceutical, cosmetic, agricultural and food industries.