Effect of matrix pretreatment on the supercritical CO2 extraction of Satureja montana essential oil

The effect of different matrix pretreatment of winter savory(Satureja montana L.) on the supercritical CO2(SC-CO2) extraction - yield, composition and antimicrobial activity of extracts and essential oil (EO) was investigated. Herb matrix was submitted to conventional mechanical grinding, physical disruption by fast decompression of supercritical and subcritical CO2 and physical disruption by mechanical compression. The analyses of the essential oil obtained by SC-CO2 extraction and hydrodistillation were done by GC/FID method. Major compounds in winter savory EO obtained by SC-CO2 extraction and hydrodistillation were: thymol (30.4-35.4% and 35.3%), carvacrol (11.5-14.1% and 14.1%), γ-terpinene (10.2-11.4% and 9.1%) and p-cymene (8.3-10.1% and 8.6%), respectively. The gained results revealed that physical disruption of essential oils glands by fast CO2 decompression in supercritical region (FDS) achieved the highest essential oil yield as well as highest content of thymol, carvacrol and thymoquinone. Antimicrobial activity of obtained winter savory SC-CO2 extracts was the same (FDS) or weaker compared to essential oil obtained by hydrodistillation