FENNEL

Foeniculum vulgare Mill.

Family : Umbelliferae

Other names: Common fennel; sweet fennel; Florence fennel; spigel

Description

Fennel is an erect growing perennial herb native to southern Europe and the Mediterranean area, commonly grown for flavoring purposes. The mature seeds are the dried fruits of this herb which are used commercially, and the young tender shoots and leaves of the sweet fennel are used in foods in European countries. This plant has a thickened base of leaves, which can be blanched or boiled and eaten as a vegetable. Principal fennel production areas are located in India, the People's Republic of China, Egypt, Argentina, Indonesia, and Pakistan. Fennel has been known to herbalists and doctors since time immemorial. It was believed to be the total cure and have the power to make people young, strong and healthy. It is one of nine Anglo-Saxon sacred herbs. It was often hung over doorways to ward off evil spirits. Fennel was used in ancient Greece and Rome. The name comes from the Latin foenum, a variety of fragrant hay, reflecting the plant's odour .

Botany

Fennel is a greyish-green, strong-smelling herbaceous perennial, with slim stems, bearing soft lacy, dark green leaves with thread-like lobes and swollen bases. Creeping rootstock gradually extends plant into a sparse clump. Reaching a height of 1.5 meters, the plant has small mustard-yellow flowers on a compound umbel. The fruit splits into two seeds, which are oval in shape with five ridges. The seed is light green to gray, about 0.75 cm long, and curved.

Cultivation

The reported life zone of fennel is 4 to 27 degrees centigrade with an annual precipitation of 0.3 to 2.6 meters and a soil pH of 4.8 to 8.3. Fennel thrives on well drained loam soil. The seeds should be planted early in spring to a depth of half an inch and at the rate of a dozen seeds to the foot and the plants thinned to 4 to 6 inches apart in the row. Only light cultivation for weed control is necessary. Ordinarily the plants do not flower the first season, but a full crop of seed will be produced for several seasons thereafter.

Although a perennial, fennel is generally grown as an annual or biennial crop. Yields of the dried fruit, commonly thought of as fennel seed, are low in the first year but increase in the second. The seeds mature in the fall of the second season. When the fruiting umbels turn brown they are ready for harvest and should be cut promptly to prevent shattering. The umbels do not mature uniformly, and several harvests are therefore necessary to maximize yield. Mechanical harvesting of commercial stands must be carefully timed to obtain high yields. The tops containing the seeds may be spread on fine screens or on a clean wooden floor to dry. When drying is completed they should be separated from the stems, cleaned, and stored in bags. The leaves lose most of their sweet aromatic flavor on drying. Approximately 60 percent of the essential oil is located in the fruit, with the rest in the rays of the umber and other green plant parts.

Aroma and flavour

Fennel contains 1 - 3% of a volatile oil which is composed of about 50 - 60% anethole and about 20% d-fenchone. Other compunds present in fennel are d-a-pinene, d-a-phellandrene, dipentene, methyl chavicol, feniculun, anisaldehyde, and anisic acid. Oil of fennel is commonly available. An oleoresin is also available with a volatile oil content of only about 3 -6%. Bitter fennel oil is thought to contain more fenchone (a bitter mixture with a camphor-like odor and flavor) and less anethole than sweet fennel oil. Sweet fennel oil is of a superior quality with a more pleasing aroma and flavour. Some analyses have indicated a lack of fenchone in sweet fennel and high concentrations of limonene in bitter fennel.

Culinary use

Both the seeds and the oil distilled from them are used for flavoring. Fennel seed is used in the food and flavour industry for addition to meats, vegetable products, fish sauces, soups, salad dressings, stews, breads, pastries, teas, and alcoholic beverages. Crushed seed are used in salad dressings, in mayonnaise, in savoury and sweet baking and as a substitute for juniper in flavoring gin. Ground fennel is used in many curry powders. The essential oil and the oleoresin of fennel are used in condiments, soaps, creams, perfumes, and liqueurs. Several types of fennel differing in morphology and leaf color are available for ornamental use and as a fresh vegetable. Soft growing tips are widely used to flavour and garnish fish dishes, soups and baked foods.

Medicinal and other use

As a medicinal plant, fennel seed has been used as an antispasmodic, carminative, diuretic, expectorant, laxative, stimulant, and stomachic. Roots once boiled as a vegetable, and used as an expectorant in cough mixtures. Fennel has also been used to stimulate lactation, as a remedy against colic, and to improve the taste of other medicines. Chinese herbal medicine includes the use of fennel for gastroenteritis, hernia, indigestion, abdominal pain, and to resolve phlegm and stimulate milk production. Fennel is known to provoke both photodermatitis and contact dermatitis in humans. The volatile oil may cause nausea, vomiting, seizures, and pulmonary edema. The essential oil has been reported to stimulate liver regeneration in rats. It has antibacterial properties.