Study of methods for extracting essential oils from Tunisian Origanum spice and their anticandidal activities

Two different extraction methods were used for a comparative study of the essential oils of the Tunisian majoram leaf: Clavenger and infusion. Clevenger-type hydrodistillation extraction produced high quality essential oils. Comparison of the total essential oil yield quantified by Clevenger-type hydrodistillation of the majoram (0.75%) with the essential oil yields of infusion extracts (varying between 0.021% and 0.036%) revealed that only 20% of the initial oil could be extracted by infusion. With regard to the essential oil composition, we noted significant differences when focusing on the relative proportions of the chemical classes of the constituents determined by comparing both extracts. MIC values of O. majorana essential oil ranged from 0.781mg/mL to 12.5 mg/mL. The most important activities were observed against C. albicans and C. Para psilosis. EO obtained with the Clevenger method was characterized by the lowest MIC values, due to its richness in bioactive compounds acting in synergy.