Changes in composition and antioxidant and antimicrobial activities of essential oil of fennel (Foeniculum vulgare Mill.) fruit at different stages of maturity.

摘要

Chemical composition and antioxidant and antimicrobial activities of hydro-distilled essential oils from fruits of sweet fennel (Foeniculum vulgare) were investigated at 3 stages of maturity (immature, intermediate and mature). Max. essential oil content (3.5%) was observed in the mature, and min. oil content (2.8%) was observed in immature fruit. GC-MS analysis of the fennel essential oils from the plants revealed the presence of trans-anethole (65.2, 69.7 and 72.6%), fenchone (8.8, 10.0 and 11.0%), estragole (6.9, 6.9 and 7.2%) and limonene (7.8, 4.7 and 3.5%) as the main components at immature, intermediate and mature stages, respectively. Both the essential oils and trans-anethole, the principal constituent, exhibited appreciable antioxidant and antimicrobial activities as assessed by 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging ability, bleaching of beta-carotene in the linoleic acid system, inhibition of linoleic acid oxidation, disc diffusion and microdilution broth assays. The variations in contents of most components with antioxidant and antimicrobial activities in the essential oils as the fruit matured were significant (P < 0.05).