Fennel Oil
Ravid et al. (1992) determined that the range of fenchone content of sweet fennel oil (Foeniculum vulgare var. dulce) was 2.2–5.2%, whereas in bitter fennel oil (F. vulgare var. vulgare) it was 7.2–20.4%. The authors further determined that the enantiomeric distribution of fenchone in both sweet and bitter fennel seed oil was (+)-fenchone (100%): (-)-fenchone (0%). As a result, fennel oil would make an excellent source of (+)-fenchone.
Gora et al. (1997) reported that Polish fennel seed oil contained fenchone (19.1%) and (E)-anethole (69.4%). This fenchone level indicates that the oil was produced from bitter fennel. The major constituents of bitter fennel oil produced in the laboratory by Bas¸er et al. (1997) from seeds of Uzbekistani origin were found to be:
limonene (0.78%)
gamma-terpinene (0.39%)
fenchone (8.03%)
methyl chavicol (3.24%)
(E)-anethole (87.33%)
Aridogan et al. (2002) reported that fennel oil produced in Turkey contained the following major constituents:
alpha-pinene (0.3%)
limonene (7.7%)
1,8-cineole (1.6%)
gamma-terpinene (0.9%)
fenchone (3.3%)
methyl chavicol (3.2%)
(E)-anethole (76.4%)
anisketone (1.2%)
