Investigation of the composition and stability of the essential oils of Origanum vulgare ssp vulgare L. and O-vulgare ssp hirtum (Link) letswaart

The essential oils of Origanum vulgare L, ssp. hirtum (Link) letswaart and Origanum vulgare L ssp. vulgare (Farr, Lamiaceae), cultivated in Hungary, have been studied by GC and GC-MS and the qualitative and quantitative chemical composition of the essential oils in the two species have been compared. O.vulgare ssp, hirtum oil was found to contain carvacrol (76.4%), gamma-terpinene (6,698), thymol (0.23%), and p-cymene (4.7%) as the main constituents whereas the major compounds in O.vulgore ssp. vulgare oil were p-cymene (22.3%), caryophyllene oxide (10.2%), sabinene (7.9%), gamma-terpinene (5.1%), thymol (0.34%), and spathulenol (4.8%). The stability of content and composition of the oils during the flowering period (economically beneficial period) were observed. The effect of long-term storage on the composition of the oil was also investigated for both the crude and distilled oil of Origonum vulgare ssp. vulgare.