Abstract
Foeniculum vulgare (Apiaceae) commonly known as fennel is a well-known and important aromatic plant widely used as carminative and gastrointestinal disorders. This investigation was initiated to study the effect of different gamma radiation doses on volatile oil constituents, fatty acid composition and antimicrobial activity of fennel (F. vulgare) seed extracts. Fennel seeds were irradiated with 0, 5, 10 and 20 kGy gamma radiation. Volatile oils were extracted and analyzed by gas chromatography-mass. The GC-MS analysis in the non-treated sample showed different phytoconstituents mainly, p-allylanisole (71.40%), D-limonene (12. 35%) and c-terpinene (5.17%). Fatty acids of the extracted oils were separated by gas chromatography mass spectroscopy. The results demonstrated that, all radiation treatments had effect on the fatty acid composition, and some fatty acids did not seem to be affected by the radiation treatments. The antimicrobial activity of the volatile oil and hexane crude extract were assayed. The results showed that, fennel volatile oils exhibited strong and a variable degree of antimicrobial activity compared to the hexane crude extract. This study demonstrated that the treatment of F. vulgare seeds with gamma irradiation could be considered as a useful tool that stimulate and influence the volatile oil composition and the antimicrobial activity.