Name as currently accepted: Anethum graveolens
Taxonomic serial no.: 29584 (ITIS, 2016)
Synonyms: Anethum graveolens ssp. sowa (Roxburgh) N.F. Koren, Anethum sowa Roxburgh, Peucedanum anethum Baillon, Peucedanum graveolens (L.) Hiern., Peucedanum graveolens (L.) Hiern., Peucedanum sowa (Roxburgh) Kurz., Angelica graveolens (L.) Steus. (Anon., 2010).
Family: Apiaceae (Kingdom: Plantae; Subkingdom: Viridiplantae; Infrakingdom: Streptophyta; Superdivision: Embryophyta; Division: Tracheophyta; Subdivision: Spermatophyta; Class: Magnoliopsida; Superorder: Asteranae; Order: Apiales; Family: Apiaceae; Subfamily: Apioideae; Tribe: Peucedaneae; Genus: Anethum; Species: graveolens L; Binomial: Apium graveolens L.).
Infraspecific categories: Anethum graveolens ssp. australe N.F. Koren; Anethum graveolens var. anatolicum N.F. Koren; Anethum graveolens var. copiosum N.F. Koren; Anethum graveolens var. nanum N.F. Koren; Anethum graveolens var. parvifolium N.F. Koren; Anethum graveolens var. sowa (Rox.) Kuntz., Anethum graveolens var. tenerifrons N.F. Korens (Anon., 2010).
Common names: Dill, East Indian dill, fern leaf dill, garden dill, Indian dill.
Vernacular/regional names: Arabic: bazrul shibbat, shabath, shibit, shibitt, sjachet, sjamar, sjamar (Egypt); Bulgarian: kopăr, kopur; Chinese: chou qian hu, ou zhou shi luo, shang hui xiang, shi luo, tu hui xiang, yang hui xiang, ye xiao hui; Czech: celer apíkatý, celer bulvový, celer bulvový, celer hlíznatý; Danish: dild; Dutch: dille, stinkende vinke; Finnish: ryytitilli, tilli; French: aneth, aneth odorant, fenouil bâtard, fenouil bâtard, persil des marais; German: dill, gurkenkraut; Greek, modern: ánētos, anitho, anitos; Hindi: anithi, sotapa, sowa, sua bathi, suwa bhaji; Hungarian: kapor; Indonesia: adas cina, adas manis, adas sowa, ender; Italian: aneto, aneto odoroso; Japanese: deiru, i-no-n-do, inondo; Korean: dil, i-non-deu, inondu, tir; Norwegian: dill; Persian: šbt, shebet, sheveed, shiwit, šwýd, tukhme shibbat; Polish: koper ogrodowy; Portuguese: aneto, endro, funcho (Brazil), funcho-bastardo; Romanian: mărar; Russian: ukrop; Spanish: abesón, anega, aneldo, aneto, eneldo, ezamillo, falso anís, hinojo falso, hinojo hediondo; Swedish: dill; Thai: dil, pak chee lao, thiam khao pluak; Turkish: börek otu, dereotu, şibit, tarak otu, tarhana out; Ukrainian: koper, krip, krip zapashnii (krip zapashnyj; Vietnamese: thì là, thìa là, hương (Katzer, 2008; Anon., 2013a).
Dill is a spice cultivated and used widely. The name dill, meaning to calm or soothe, probably has originated from the plant's known ability to calm troubled stomachs and colicky infants (Wright, 2013). The name Anethum is derived from the Greek ano (upwards) and theo (I run), components with reference to a fast-growing plant and is a Greek name for dill. The species epithet graveolens is derived from the Latin gravis (heavy, weighty) and oleo (to emit an odour, smell) components meaning ‘strong-smelling or heavily scented’. The two terms together means an upward fast-growing strongly aromatic plant (Eland, 2008).
Dill is believed to have originated in the Mediterranean region from where it has spread to most geographic regions and countries. Dill has a long and ancient history in many countries as a medicinal and culinary herb. The Egyptians were known to have used it 5000 years ago and around 3000 BC the Babylonians were known to have grown dill. The Greeks were using it from ancient times as a medicinal and culinary herb and they used to add dill to the oil for burning. In the ancient and medieval periods, dill was believed to provide protection from witchcraft and people thought that if a witch cast a spell the cure could be found by drinking a cup of dill water. It was added to love potions for its attributed aphrodisiac effect. The herb was also believed to bring happiness and good fortune to marriages. In Germany and Belgium, brides would attach a sprig of dill to their wedding gowns or they would carry it in their bouquets in the hope that happiness would bless their marriages (Le Strange, 1977; Wright, 2013).
The dill plant is an erect herb, annual or biennial in nature; when cultivated it is grown as an annual. It grows to 50–150 cm depending on the variety. Detailed botanical descriptions of the species are available in Jansen (1981), Thi Tam et al. (1999) and Menglan and Watson (2005). The plant is glabrous and strong smelling. The stem is terete to subterete, branched, blue–green to dark green, and internodes are often hollow. Leaves are sheathed, with the sheath base covering the stem; they are alternate, decompound, petiolate, petiole is subterete, sulcate, longer in lower leaves, and in higher leaves may even be sessile.
Leaf blades are triangular or ovate in outline, up to 30 × 50 cm, often smaller, pinnately divided into c. 2–6 pairs or whorls of primary pinnae and one top pinna; each pinna is again 2–4 times pinnately divided into linear or filiform, acute, blue–green or dark-green lobes; lobes of the lower leaves are usually broader and shorter than those of the higher ones. The inflorescence is a compound umbel, c. 4–16 cm diameter; the peduncle is stem-like, c. 4–30 cm long; bracts and bracteoles are usually absent. Primary rays are terete to subterete, finely sulcate, unequal in length, the longest at the outside of the umbel, blue–green to medium-green. Secondary rays are terete, finely sulcate, unequal in length, the shortest near the centre of the umbellet. All flowers are bisexual and actinomorphic, often some central ones remaining rudimentary; flowers are protandrous (usually the styles and stigmas becoming fully developed after shedding of the corolla and stamens).
The calyx is vestigial, sometimes five very small light- or dark-green teeth at the top of and adnate to the ovary. The corolla consists of five petals, distinct, subovate in outline, top strongly inflexed, glabrous, yellow, with a thin membranous outgrowth on the ventral side of the midrib from the base to nearly the top; the margin is entire, usually notched at the apex. Stamens are five, distinct, alternating with the petals; filaments are conical, the fleshy base tapering towards the filiform apex, yellow, inflexed in bud; anthers are dorsifixed, two-celled, yellow, dehiscing by longitudinal slits. The pistil consists of an inferior ovary, usually with eight protruding, rather broad, longitudinal, sub-parellel ribs; bilocular, with one pendulous ovule per locule. The fruit is a schizocarp, usually erect and lens-shaped, splitting at maturity into two mericarps. Seeds germinate epigeally. The chromosome number is 2n = 22 (Jansen, 1981; Thi Tam et al., 1999; CCDB, 2015).
Indian dill, grown widely in North India (formerly classified under the species Anethum sowa), is a distinct botanical variety (Anethum graveolens var. sowa 2n = 22) that has a high content of the toxic compound dill apiole and is distinct from European dill, which is free of apiole. This variety (var. sowa) has an inflorescence with fewer primary rays; its fruits are less flat but longer with more prominent ridges and the essential oil from the fruits is chemically different (less carvone but containing dill apiole). The Indian type of dill predominates in South-east Asia (Thi Tam et al., 1999). Breeders have developed apiole-free cultivars through breeding, such as the Ajmer dill-1 (3.5% oil and apiole free) (Gupta et al., 2012).
There are distinct morphotypes (cultivars) of dill that are under cultivation. The more important ones are: Bouquet (tall, early, leaves with superior flavour); Delikat (dense foliage, very high seed yield); Dukat (long duration Danish dill, dark green foliage, high flavour); Long Island mammoth (tall), Vierling (tall, long duration), Hercules (tetraploid, slow flowering), Fernleaf (dwarf plants, foliage with superior colour and flavour, an award winning cultivar), Mammoth (vigorous tall, early) and Tetra (bushy, compact, slow maturing). Ajmer dill-1 (AD-1, a selection from Mammoth) and Ajmer dill-2 (a selection from the Nagpur local type) are the improved lines developed in India (Malhotra, 2006; Gupta et al., 2012; Wright, 2013).
Duke (2016) has provided a detailed listing of the chemical constituents of dill. Dill seed contains about 2.5–4% volatile oil; variations are noted based on variety and location. Dill seed contains a xanthone glucoside (dillanoside), coumarins (scopoletin, esculetin, bergapten, umbelliferone, umbelliprenine, etc.), flavonoids such as kaempferol, its glucuronide, vicenin and its glycoside, petroselenic acid triglyceride, β-sitosterol and phenolic acids (caffeic, ferulic and chlorogenic). Seed volatile oil contains mainly carvone (35–60%), D-limonene and β-phellandrene, α-pinene, anethole, dillapiole, myristicin, carveol and others. Dill herb oil contains mainly α-phellandrene, limonene and carvone, with minor ones including terpinene, α-pinene, dillapiole, myristicin and two coumarins among others (Baslas et al., 1971; Ishikawa et al., 2002; Amin and Salim, 2007; Singh et al., 2008; Khan and Abourashed, 2010).
Indian dill contains 2–6% oil and other components include kaempferol, isorhamnetin, quercetin and its glucuronide, petroselenic acid, β-sitosterol, etc. Volatile oil contains mainly carvone, dihydrocarvone and limonene. Indian dill has the toxic component dill apiole in varying concentration, often in a significant amount. There are many reports supporting the general chemical profile given above (Shankaracharya et al., 2000). Rădulescu et al. (2010) found that the cultivated dill from Romania contained mainly α-phellandrene (62.71%) in the leaves, with 30.26% in the flower. Limonene content was 33.22% in the flower and 13.28% in the leaves. Dill ether was present to the extent of 22% in flower and 16.42% in the leaves. Seeds contain 75.21% carvone, 21.56% limonene and 3.02% trans-dihydrocarvone. Saleheen et al. (2010) analysed a sample from Bangladesh and reported 25.39% dill apiole, o-cymene (15.25%), α-thujene (14.84%), β-phellandrene (7.17%), 6,6-dimethyl-2-(3-oxobutyl) bicyclo (3.1.1) heptan-3-one (6.90%), exo-2-hydroxycineol (5.03%), limonene (4.13%), 3-isopropyl-4-methyl-1-pentyn-3-ol (2.89%), myristicine (2.46%) and dihydroumbellulone (2.14%). Singh (2012) reported 83% limonene in a sample of Indian dill, in which the carvone content was only 1.5%. Available chemical information points to the existence of several chemotypes of dill, which can be distinguished on the basis of the predominant essential oil components. The major components of the chemotypes are: (i) limonene–carvone–myristicin–n-dillapiole; (ii) limonene–carvone–dill apiole; (iii) limonene–carvone; (iv) carvone; (v) α-phellandrene–limonene–anethofuran, etc. (Badoc and Lamarti, 1991; Rădulescu et al., 2010). Dill herb (the aerial portion) contains an essential oil, the important components of which are α-phellandrene (31.8%), apiole (15.3%), dill ether (13.2%), limonene (11.8%), geraniol (10.6%) and p-cymene (5.3%) (Rana and Blazquez, 2014).
Duke (2002) has compiled the reported activities of dill; however, experimental proof is lacking for most of these functional properties; only some preliminary leads are available in some cases. The major functional properties are given below.
- Adaptogenic effect: The administration of aqueous extract of dill protected experimental animals from stress-induced urinary biochemical changes dose-dependently. The extract also significantly inhibited lipid peroxidation in both rat liver and brain, compared to a reference standard anti-oxidant, ascorbic acid, and also led to cognition enhancement. The authors concluded that dill extract has anti-stress, anti-oxidant and memory-enhancing activities (Koppula and Choi, 2011).
- Anti-hypercholesterolaemic effect: The administration of dill extracts consecutively for 14 days in a rat model reduced the triacylglycerides and total cholesterol levels by almost 50% and 20%, respectively. Oral administration of the essential oil of dill seeds, at two different doses, also reduced the triacylglyceride levels by almost 42%. The total cholesterol level was not reduced by the same doses of the essential oil (Yazdanparast and Alavi, 2001).
- Spasmolytic effect: Dill seed oil has a spasmolytic effect on smooth muscles, especially those of the gastrointestinal tract. A 5% emulsion in physiological saline administered intravenously to cats (5–10 mg/kg) increased respiratory volume and lowered blood pressure, whereas guinea pigs receiving a higher dose (35 mg/kg) via intraperitoneal injection went into anaphylactic shock (Khan and Abourashed, 2010).
- Effects on the nervous system: Dill oil has been found to inhibit butyrylcholinesterase at 200 μg/ml, with the n-hexane extract causing 46.58+/–4.77% inhibition and the dichloromethane extract inhibiting 47.92+/–5.52% of activity; there was no inhibition of acetylcholinesterase with any extract (Orhan et al., 2013).
Dill was most often regarded as an effective remedy for flatulence and as an aid for improving digestion. Ancient Greeks believed that parts of the dill plant could help with hiccups. Pliny and Dioscorides shared this belief. The Greeks also used dill as a sleep aid (Wright, 2013). Dill water, or ‘gripe water’ is an ancient remedy that has been used by mothers for centuries to calm colicky babies or to help them sleep. Dill was even recommended in the past to help mothers increase their milk flow (Wright, 2013). Today, dill is a useful remedy for indigestion and ulcers. Researchers have found that dill inhibits the secretion of stomach acids in mice and that it may help to prevent ruptures in the stomach lining (Wright, 2013).
In Indian Ayurvedic medicine, dill is used mainly as a carminative, stomachic and anti-spasmodic. The dried leaf is used for the prevention or treatment of disease and disorders of the gastrointestinal tract, kidney and urinary tract and for sleep disorders and spasms (Khare, 2007).
The characteristic, sweet taste of dill is popular all over Europe, and in Western, Central and Southern Asia. In Europe, it is mostly used for bread, with vegetables (especially cucumber), pickles and fish; for the last application, the leaves are preferred. Furthermore, it is very useful for herb-flavoured vinegars (Katzer, 2008). In home cooking, both dill seed and dill leaves are used for flavouring. Dill seed has a bitter taste, whereas leaves give a more pleasant flavour. The seeds are often used as a spice and can be combined with onions, cabbage, potatoes, cumin, chilli powder and paprika. Additionally, they can be used with lamb, fish and vegetable dishes, as well as in sauces (Wright, 2013). Dill seeds take a long time to release their flavour so it is best to add them early on in the cooking process. Dill vinegar can be made by adding the seeds to vinegar and allowing the mixture to steep for several days. The dill herb also has a taste similar to that of anise and caraway but the flavour is stronger and more pronounced. Chopped or whole dill herb can be added to soups, stews, casseroles, meat dishes, pasta and eggs. It can also enhance the taste and acceptability of all types of sauces (Raghavan, 2007; Wright, 2013).
Wright (2013), as well as Katzer (2008), has provided the following details on the use of dill in various cuisines. In Sweden, dill is popularly used in the dish known as gravlax (salmon pickled in salt, sugar and dill). Gravlax is served as an appetizer together with a dill and mustard sauce. In Sri Lanka, dill flowers are added to salads. In French cuisine, dill seeds or seed powder are sprinkled on pastries and baked foods. In North Africa dill seeds are used with most meat dishes. In the Middle East, dill is added to rice, beans, meat, spinach, salads and vegetables. People of Greece use it in their cooking and also for making dolmadakis vine leaves filled with a mixture of dill leaves, rice, garlic and pine seed. In Holland, dill-milk (dill steeped in milk) is given for inducing sleep. In Turkey, dill is mixed with beans and also with other spices in salads. In Russia, it is used to make dishes like borscht and pickles. In Germany, dill is most popular as dill pickles (Wright, 2013).
Fresh dill leaves (dill herb) is a kind of national spice in Scandinavian countries, where fish or shellfish dishes are usually either directly flavoured with dill or served together with sauces containing dill. German cooks also tend to use dill mostly for fish soups and stews (Katzer, 2008). Dill herb is also quite popular in Iran. It is usually employed for rice and bean dishes. In India, particularly in Punjab, dill is an occasional spice for lentil and bean dishes. In Gujarat, it appears in fried vegetables. In India, the herb is generally not much used but just the seeds, which have a more pungent flavour than the European dill. Like many related spices, dill fruits are quickly fried in hot fat or oil to develop the aroma fully (Katzer, 2008).
Dill oil is used in very many baked and ready-made foods, as well as in alcoholic and non-alcoholic beverages, frozen dairy desserts, cheese, snack foods, gravies, and others, with the highest average maximum use level of 0.075% reported in snack foods (Khan and Abourashed, 2010). Several types and varieties of dill recipes are available the world over and many are available online (e.g. Anon. 2013c, 2016a,b) and Dalal (2016).
Dill is classified as generally safe (GRAS), hazards and/or side effects are not known for proper therapeutic dosages. Contact photodermatosis is possible, as in most Apiaceae members. Fresh juice may cause photodermatosis. The drug is contraindicated in inflammation of the kidneys. An overdose of oil or dill seed should be avoided by women of reproductive age (Duke, 2002).
The dill population grown in India (formerly included under the species Anethum sowa) contains dill apiole (apiol) in varying levels; some varieties even to the extent of 25–30%. Apiole is toxic and causes nausea, menstrual changes, abortion and damage of the liver and kidney. It is a very potent inhibitor of CYP3A4, a member of the cytochrome P450 family of mixed oxidases, found largely in the liver and involved in the detoxification process. This in turn can lead to liver damage. The National Institute of Health reports indicated that, in test animals, apiole causes spastic paralysis with or without sensory change, affects lungs, thorax or respiration and causes behavioural changes such as altered sleep time (including change in the writhing reflex) (Anon., 2013b). So the use of dill oil should be regulated, and pregnant women and those with liver and kidney problems should avoid the use of Indian dill oil in large quantities.
A tall, hardy annual, Anethum graveolens , from the Mediterranean and southern Russia with feathery leaves and clusters of tiny brown seeds...
A widely cultivated annual or biennial European herb, Anethum graveolens , 60 cm high. The smooth stem bears feathery leaves and...
Aromatic annual herb native to Europe. Its small oval seeds and feathery leaves are used in cooking. Family Apiaceae/Umbelliferae; species ...