Sweet fennel

The two enantiomers of fenchone occur in a number of essential oils. Optically pure (15) (-f)-fenchone has been detected in bitter fennel oil Foeniculum vulgare var. vulgare) and in sweet fennel oil F. vulgare var. dulce) from various sources.It has also been reported to exist in... 

Anethole can be crystallized from oils in which it occurs as a major component (star anise and sweet fennel oils), and estragole containing oils (e.g., basilicum oil). 

Sweet fennel Foeniculum vulgare MUl. subsp. vulgare var. duke ( )-Anethole (more than 75), fenchone (less than 5)... 

This is distilled from the fruit of F. dulce, its main constituents being limonene (20-25%), fenchone (7-10%) and transanethole (4—6%). Arctander (1960) placed the oil in the sweet, non-floral, candy-flavoured group. In the USA, the regulatory status generally recognized as safe has been accorded to fennel oil, GRAS 2481, and sweet fennel oil, GRAS 2483. 

In summary, Foeniculum is stated to have three species, F. vulgare (fennel), F. azoricum Mill. (Florence fennel) and F. dulce (sweet fennel). Fennel is widely cultivated, both in its native habitat and elsewhere, for its edible, strongly flavoured leaves and seeds. The flavour is similar to, but milder than, that of anise and star anise. Anethole and fenchone are the major constituents of the solvent extract of seed phenols, free fatty acids, carbohydrates, proteins, vitamins and minerals have been reported in varying proportions. In the mature fruit, up to 95% of the essential oil is located in the fruit, greater amounts being found in the fully ripe fruit. Approximately 45 constituents have been determined from fennel seed oil, the main constituents being frans-anethole, fenchone, estragol (methyl chavicol), limonene, camphene, a-pinene and other monoterpenes, fenchyl alcohol and... 

Gilligan, N.P. (2005) The palliation of nausea in hospice and palliative care patients with essential oils of Pimpinella anisum (aniseed), Foeniculum vulgare var. dulce (sweet fennel), Anthemis nobilis (Roman chamomile) and Mentha x piperita (peppermint). International journal of Aromatherapy 15(4), 1 63-167. 

Box 7.17 Analysis data for Sweet, Fennel (Foeniculum vulgare) ... 

TABLE II. Comparative Chemical Composition of Bitter and Sweet Fennel Oils of Different Origins... 

Bitter Fennel Oils Sweet Fennel Oils... 

Fennel Oil (Foeniculum vulgare) You can check out Table II in the Anethole section for a good composite of bitter and sweet fennel oils. An even better reference can be seen Table XIX which is the consolidated data of a global survey of fennel seed oil with the sole objectives for quantification being the fenchone, anethole and methyl chavicol contents [2, vol. V,p. 133]. 

The oil varies to a considerable extent according to its origin. The chief constituent of the sweet fennel oil is anethole, to which the taste is due, but, as is frequently the case, even when, as in this oil, the percentage of the chief constituent is as high as 80 to 90 per cent, the taste is modified by the presence of small quantities of other substances, (Compare cassia, and cinnamon, cloves and pimento) fenchone, for example, giving it a camphoraceous odour. 

Japanese fennel fruits somewhat resemble those of anise in appearance, but are more oblong and do not taper to the apex. Umney Pharm. J. 1896, 57, 91) obtained 2.7 per cent of pale yellow oil with the odour of sweet fennel. The solidifying-point was 7° C., melting-point 10°. When fractionated, the following fractions were obtained below 220°, 26 per cent 220-225°, 32 per cent 225-230°, 34 per cent residue, 8 per cent. According to Umney, this oil probably contains 75 per cent of anethole 10 per cent of fenchone (by reduction and acetylisation), with some pinene and dipentene it is not stated how the last two were identified. 

The essential oil of fennel seeds from the USA, Germany and India was separated by steam distillation or selective C02-extraction. Both procedures gave similar essential oil yields of about 6% for the German and US material (bitter fennel) and 2% for the Indian material (sweet fennel). Under stressing conditions the main component, trans-anethol (sweet taste), can be isomerised into c/ -anethol (not sweet), or can be oxidised to anisaldehyde, as shown in Fig. 2.30. Both compounds can simply be detected by HPLC-UV as trace components in fennel oils. Their content should be as low as possible, since fennel oil with more than 2% of anisaldehyde is considered to be spoiled by oxidation and cA-anethol has a 15-times higher toxicity compared to the natural trans-isomtv. 

Source Foeniculum vulgare Mill. (Apiaceae). A distinction is made between bitter fennel of the species F. vulg. ssp. vulgare var. vulgare, which is required by some pharmacopoeiae [98], and sweet fennel (var. dulce), which is normally used as a seasoning. 

Composition E-anethole (bitter fennel 55-75%, sweet fennel 80-95%), fenchone (bitter fennel 12-25%, sweet fennel below 1%), methyl chavicol (2-6%), limonene, a-pinene, a-phellandrene, cis-anethole and anisic aldehyde. For further constituents see [99,100]. Ravid et al. ]101] employed chirality GC to prove that enantiomerically pure (-i-)-fenchone is present in fennel oil. 

Output 401 (bitter and sweet fennel oil). Main producers Russia, Hungary, Bulgaria. 

FENNEL FRUIT Foeniculi fructus The schizocarpic fruit of Foeniculum vul tare, Mill., family Apiaceae, which is a herbaceous plant, endemic to the Mediterranean aera. The fennel fruit contains 2-6% volatile oil, FomicuU aetherokum, which has a bitter camphor-like taste of the optically active (-1-) fenchone (called BITTER FENNEL, Foeniculi amari fructus,) with minimum 60% anethole and 15%, fenchone, and the SWEET FENNEL, Foeniculi dulcis fructus, with trans-anethole 80%. 

Sweet fennel For neuromuscular spasms, rheumatism and arthritis, bronchitis, whooping cough as a nerve tonic in relieving stress and nervous tension... 

Compound Spirit of Juniper. Stinmhmt ami diuretic, administered in doses of 2 to 4 dratihms. This spirit, when mixed with 2 or 3 times its weight of proof spirit, makes a fair imitation of Holland gin. Take 15 ounces bruised juniper berries, 2 ounces each of bruised caraway and fennel, 1 Ilon proof spirit, and about 1 quart water. Distill 1 gallon. The wholesale preparation is a solution of 2 drachms oil of juniper, h drachm each of the oils of caraway and sweet fennel, in 5 quarts proof spirit. If not clear, filter through magnesia. 

Fig. 3A, B The major constituent of the essential oils 1-6 is detectable VS reagent as a red-violet to brown-violet zone at R, 0.9-0.95. In the essentia] oil of anise (1), staranise (2), bitter fennel (3) or. sweet fennel (4) it is anethole (Tl) with smaO amounts of the isomer methylchavicol, while basil (5) has predominantly methylchavicol which has the same R, value as anethole. The prominent zone of sassafras oil (6) is safrole (T2). Anethole (Tl) and safrole (T2) can be separated in the solvent toluene (see Fig. 4C), where safrole then shows a higher R, value.

The blue zones in the R, range 0.1-0.4 of the oils 1-6 are terpene alcohols (e.g. linalool at Rf 0.4) at a very low concentration in the samples 1-2, slightly higher in bitter fennel (3) and sweet fennel (4), while basil (5) shows three inten.sive blue terpene alcohols with linalool as a major compound. In basil oils, linalool can be the predominant compound with very little methylchavicol (chemo- or geotype). A red-violet zone at R, 0.5, as in samples 2-5, can occur (e.g. epoxidihydrocaryophyUene). 

B Fenchone, if present in a lower concentration, can be detected by the PMA/PM reagent only. The dark blue-coloured zone of fenchone (T4) is seen in the sample of bitter fennel (3) (12%-22% fenchone), whereas a weak whitish zone is detected in sweet fennel (4) (0.4%-0.8% fenchone). Fenchone is absent in ani.se (1) or star anise. 

Fennel, Large fennel sweet fennel. Dried, ripe fruit of cultivated varieties of Poentculum vutgare Mill., Vmbelliferae. Habit. Southern Europe, Western Asia, widely cultivated. Contains 3-4% volatile oil. 

Oil of Fennel. Volatile oil from the dried fruit of Foeniculum vulgare Mill., Umbelliferae. Also from the sweet fennel plant (var. duke). Constit 50-60% anethole, —20% fenchone, pinene, limonene. dipentene, phellandrene. 

In the Bacillus subtilis DNA-repair test, sweet fennel essential oil showed some mutagenic activity, while in the chromosomal aberration test in Chinese hamster fibroblast cells (Sekizawa and Shibamoto 1982), fennel essential oil showed no mutagenic activity (Ishidate et al. 1984). 

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