The oil extracts were subjected to GC-MS analysis for identification of their chemical composition. GC-MS analysis was performed using a Thermo Scientific ISQ single quadrupole GC-MS, equipped with HP-5 MS capillary column (30m x 0.25mm x 0.25μm). For GC-MS detection, an electron ionization system was used (70eV ionization energy). The carrier gas was helium at a flow rate of 1 ml/min. Injector, ion source and MS transfer line temperatures were set at 250°C. The column temperature was initially kept at 50°C for 1 min, and then gradually increased to 280°C at a rate of 10°C/min, with a final 5 min of heating at 280°C. The injector volume was 2 μl in splitless mode. The chemical components were identified by comparing their relative retention time and mass spectra with those of standards and NIST library data of the GC—MS system.