Coriandrum sativum (PROSEA)

Plant Resources of South-East Asia
Introduction

1, flowering branch; 2, umbellet; 3, peripheral flower with enlarged petals; 4, central flower; 5, normal (non-enlarged) petal; 6, fruiting branch; 7, fruit; 8, seed

Coriandrum sativum L.

Protologue: Sp. pl.: 256 (1753).

Family: Umbelliferae

Chromosome number: 2n = 22

Synonyms

Coriandrum majus Gouan (1762),
C. diversifolium Gilib. (1782),
C. testiculatum Lour. (1790), non L. (1753),
C. globosum Salisb. (1796).

Vernacular names

Coriander, Chinese parsley (En).
Coriandre, persil arabe (Fr)
Indonesia: ketumbar (general), tumbar (Javanese), katuncar (Sundanese)
Malaysia: ketumbar, penjilang, wansui
Philippines: kulantro, uan-soi (Tagalog), kulantra (Bicol)
Cambodia: vannsuy
Laos: phak ho:m pa:nx, phak ho:m po:mz
Thailand: phakchi (central), phakhom (northern), phakhom-noi (northeastern)
Vietnam: rau mùi, ngò ta, rau ngò

Note: The name "cilantro”, often used in the United States for coriander leaves, refers also to sawtooth coriander (Eryngium foetidum L.).

Origin and geographic distribution

Coriander has its origin in the Near East. It is only known in cultivation; escapes from cultivation may become weeds. The oldest archaeological remains of coriander, dated at 6000 BC, have been found in Israel. The crop has since spread throughout the world, and different morphotypes have developed. Coriander reached South-East Asia from two directions: forms with ovoid fruits were introduced from India, while forms with small, globular fruits arrived later (after 400 AD) from China. Forms with large, globular fruits have only recently been introduced from Mediterranean or European countries.

In all South-East Asian countries coriander is grown as a culinary herb and vegetable. Cropping for its fruits is restricted to higher altitudes. In South-East Asia, as in many other parts of the world, coriander is usually grown as a small-scale horticultural crop. Large-scale production exists in southern Russia, the Ukraine and other East European countries.

Uses

Coriander fruits are commonly used as a spice, being part of a large number of dishes. Ground coriander fruits are also an ingredient of spice mixtures like curry powder (containing up to 40% of coriander). In South-East Asia the leaves or the entire young plants are popular as culinary herb and vegetable, e.g. for chutneys or in soups. Taproots are also aromatic and are commonly used as a vegetable in China, Thailand and, to a lesser extent, in other South-East Asian countries. Green plants are dried for preservation and are traded on the world market as well as the fruits.

Coriander is used in folk medicine. It has been well known since antiquity. Green plants are applied in East Asia as a cure for measles. The fruits are reported to have carminative, diuretic, tonic, stomachic, antibilious, refrigerant, anticatarrhal, antispasmodic, galactagogue, emmenagogue and aphrodisiac effects. The essential oil from the fruits is used in the flavour industry, for various basic and luxury foods, to some extent in medicine too, and in cosmetic perfumery. The extraction residues are used as feed for ruminants. In the United States the regulatory status "generally recognized as safe" has been accorded to coriander fruits (GRAS 2333) and coriander fruit oil (GRAS 2334).

Production and international trade

Although coriander is cultivated and consumed all over the world, it is difficult to obtain reliable information on production and trade. The worldwide annual area of coriander is estimated at 550 000 ha, yielding about 600 000 t of coriander fruits. Most of the crop is used as a spice, but about 10% is raw material for the distillation of essential oil, 100 t of which is traded every year. The industrial extraction of the essential oil is not practised in South-East Asia, but is important in East Europe and several industrialized countries. The main producers of fruits are the Ukraine, Russia, India, Morocco, Argentina, Mexico and Romania. The main importers of coriander fruits are Sri Lanka, the United States, the United Kingdom, the Netherlands, Germany and Japan. The largest markets in South-East Asia are Singapore (import/export) and Malaysia. In 1992, Indonesia imported about 7100 t of coriander seeds with a value of US$ 3 million.

The area dedicated to coriander as a fresh culinary herb may be estimated at 20 000 ha, but this figure should be viewed with some caution, since production is mostly for household consumption or local markets. Recently a market for dried coriander leaves has emerged in some industrialized countries (e.g. the United States import these from Mexico).

Properties

Per 100 g, air-dried fruits of coriander contain approximately: water 11 g, crude protein 11 g, fatty oil 19 g, carbohydrates 22.9 g (starch 11 g, pentosans 10 g, sugar 1.9 g), crude fibre 28 g, mineral constituents 5 g and essential oil 1.0 g. The essential-oil content varies between almost zero and 2%; small-fruited types have the highest content. The oil consists of several monoterpenoids. The main component (usually making up more than 60% of the essential oil) is always linalool. Other components, none of which accounts for even as much as 10% of the essential oil, are α-pinene, γ-terpinene, geranyl acetate, camphor and geraniol.

The composition of the monoterpenoids is largely genetically determined, and this chemical feature supports an infraspecific classification mainly based on morphological characters. Coriander originating from the Indian subcontinent (Indicum group or subsp. indicum Stolet.) has ovoid fruits, with a low content of essential oil containing little or no camphor, myrcene and limonene, but much linalool. In spite of the relatively low content of essential oil, this coriander is sometimes preferred because of its specific flavouring quality. Medium or large globose fruits with low or medium contents of essential oil (Sativum group or subsp. sativum) are characteristic of the coriander forms that developed in the Near East, northern Africa, the Mediterranean, Europe and the New World. Coriander with small, globose fruits (Microcarpum group or subsp. microcarpum DC.) developed mainly in the Caucasus and Central Asia and includes forms with the highest essential-oil content, always containing camphor, myrcene and limonene.

The content and composition of fatty oils in the endosperm of ripe fruits varies between 12-25% and is much more dependent on environmental conditions. The major fatty acid (more than 60%) is petroselinic acid (C18:1(6C)), which is an isomer of the oleic acid (C18:1(9C)) that is also present. Other components of the fatty oils are linoleic acid, palmitic acid, stearic acid, vaccenic acid and myristic acid. The high content of petroselinic acid gives the oil physico-chemical properties suitable for special technical purposes.

The use of coriander as culinary herb is based on volatile compounds with a bug-like odour contained in the roots, stems and leaves. Per 1 g fresh leaves about 4 mg of essential oil is present. About 41 volatile components have been detected in this foliar essential oil including alkenals in the C₉-C₁₆ range, C₇-C₁₇ alkanals, C₁₀-C₁₂ primary alkenols, alkanols, and nonane. The aldehydes make up more than 80% of these volatile compounds. Furthermore, the green herb's notable content of pro-vitamin A (up to 12 mg/100 g), vitamin B2 (up to 60 mg/100 g) and vitamin C (up to 250 mg/100 g) is worth mentioning.

A monograph on the physiological properties of coriander fruit oil has been published by the Research Institute for Fragrance Materials (RIFM).

The 1000-seed weight is 7-17 g.

Composition

Coriander fruit oil (Source: Anitescu et al., 1997)

63.8% linalool
5.5% camphor
4.9% para-cymene
4.6% γ-terpinene
3.3% α-pinene
2.4% limonene
1.8% geraniol
1.2% myrcene
1.1% δ-3-carene
1.0% geranyl acetate
1.0% β-pinene
1.0% α-terpineol
0.8% trans-linalool oxide (5) (furanoid)
0.7% anethole
0.6% camphene
0.6% cis-linalool oxide (5) (furanoid)
0.6% terpinen-4-ol
0.5% carvone
0.1% borneol
0.1% citronellol
0.1% eugenol
0.1% 6-methyl-5-hepten-2-one
0.1% neral
0.1% neryl acetate
0.1% sabinene
0.1% α-terpinene
trace carvacrol
trace β-caryophyllene
trace caryophyllene oxide
trace 1,8-cineole
trace p-cymen-8-ol
trace geranial
trace (Z)-3-hexenyl butyrate
trace α-humulene
trace menthol
trace α-thujene
trace thymol
96.3% total

Coriander leaf oil (Source: Potter, 1996)

15.6% (E)-2-dodecenal
12.7% (E)-2-tetradecenal
12.1% (E)-2-decenal
9.3% decanal
8.2% (E)-2-decenol
5.3% (E)-2-undecenal
5.0% dodecanal
4.8% 2-pentadecenal
2.8% phytol
2.5% (E)-2-tridecenal
2.3% undecanal
2.3% undecenal (unknown isomer)
2.1% 1-decanol
1.7% tetradecanal
1.5% 1-eicosanol
1.4% tridecanal
1.4% 1-docosanol
1.0% dodecenal (unknown isomer)
0.9% 2-hexadecenal
0.7% tetradecenal (unknown isomer)
0.7% decenal (unknown isomer)
0.6% 2-dodecenol
0.5% octanal
0.5% pentadecanal
0.5% 9-decenal
0.4% 1-tetracosanol
0.4% nonane
0.3% nonanal
0.2% 2-undecenol
0.2% pentadecenal (unknown isomer)
0.2% 4-decenal
0.1% germacrene B
0.1% tridecenal (unknown isomer)
0.1% 1-dodecanol
0.1% trans-5-methyltetrahydrofurfurylal
0.1% 1-undecanol
0.1% methyl octadecanoate
0.1% hexadecanal
trace 2-tridecen-1-ol
trace undecane
trace limonene
trace phenylacetaldehyde
trace hexadecenal (unknown isomer)
98.5% total

Adulterations and substitutes

The commercial essential oil is sometimes adulterated with sweet-orange oil, cedar-wood oil, turpentine and anethole or anise-fruit oil. The high esteem for the aromatic taste of green coriander is illustrated by the use of two other species as a substitute: Eryngium foetidum L. (Umbelliferae), known as sawtooth coriander and also as "Mexican coriander”, and Persicaria odorata (Lour.) Soják (Polygonaceae), known as "Vietnamese coriander”.

Description

Erect, annual, glabrous, usually profusely branching herb, up to 1.30 m tall with a well-developed taproot. Stem solid, subterete, up to 2 cm in diameter, older internodes sometimes becoming hollow, sulcate, mostly with a white bloom, light green with darker green ribs, sometimes with some violet.
Leaves alternate, rather variable in shape, size and number, with a yellow-green, scariously margined sheath surrounding the supporting stem for up to three quarters of its circumference; petiole and rachis subterete, sulcate, light green; blade white waxy, shiny green often with darker green veins; basal 1-3 leaves usually simple, withering early, often in a rosette, blade ovate in outline, deeply cleft or parted into usually 3 incised-dentate lobes; next leaves decompound, petiole 0-15 cm long, blade ovate or elliptical in outline, up to 30 cm × 15 cm, usually pinnately divided into 3-11 leaflets, each like the blade of the simple lower leaves or again pinnately divided into 3-7 simple leaf-like lobes; all higher leaves compound, petiole restricted to the sheath, blade divided into 3 leaflets of which the central one is largest, each often variously divided into ultimately sublinear, entire, acute lobes.
Inflorescence an indeterminate, compound umbel; peduncle up to 15 cm long; bracts sublinear, 0-2, up to 11 mm long; primary rays 2-8, up to 4.5 cm long; bracteoles 0-6, linear, up to 1 cm long; secondary rays up to 20, up to 5 mm long; usually each umbellet has bisexual peripheral flowers, and the central flowers are sometimes male.
Calyx in all flowers represented by 5 small lobes; corolla with 5 white or pale pink petals, heart-shaped, very small (1 mm × 1 mm) in male flowers, in bisexual peripheral flowers usually 3 petals are larger: 1 petal develops 2 ovate lobes of about 3 mm × 2 mm and the 2 adjacent petals develop each one lobe; stamens 5, filaments up to 2.5 mm long, white; pistil rudimentary in male flowers, in bisexual flowers with inferior ovary, a conical stylopodium bearing 2 diverging styles up to 2 mm long, each one ending in a minutely papillate stigma.
Fruit an ovoid to globose schizocarp, up to 5 mm in diameter, yellow-brown with 10 straight longitudinal ribs alternating with 10 wavy longitudinal ridges, often crowned by the dry persistent calyx lobes and the stylopodium with styles; fruit does usually not split at maturity; it contains 2 mericarps which each bear on their concave side 2 longitudinal, rather wide lines (vittae), containing essential oil.
Seed 1 per mericarp, with testa attached to the fruit wall.
Seedling with epigeal germination; taproot thin with many lateral roots; hypocotyl up to 2.5 cm long; cotyledons opposite, oblanceolate, up to 3 cm × 4 mm, pale green.

Growth and development

Some genotypes of coriander form several basal leaves, others start stem elongation immediately or after the second leaf. Flowering is protandrous and starts in the primary umbel, about 50-90 days after sowing. The peripheric florets of the umbellets are the first to flower. Coriander is cross-fertilized by insects for 50-60%; the stigma remains receptive for 5 days, pollen is fertile for 24 hours only; stamens emerge one by one. The length of the flowering period depends on the number of branches and the weather conditions, and extends up to 30 days. Thus, maturation of the umbels of different order is a successive process, and ripe fruits of the primary umbel may shatter before those of umbels of a higher degree have reached full maturity. Coriander seeds reach physiological maturity 6-7 weeks after anthesis. During ripening the aldehydic components of the essential oil disappear, and the odour of the fruits changes notably. This process continues after harvest of the fruits and is accelerated by high temperatures combined with dry weather. The time from sowing to harvesting depends very much on the genotype, and is usually between 90 and 140 days. However, since young coriander of some genotypes is frost resistant it can be cultivated as a cold-season crop over a much longer period.

Other botanical information

Coriander is a very variable species, and the botanical literature contains several subclassifications into subspecies, varieties and forms. As coriander is only known from cultivation, however, the most appropriate classification would be into cultivar groups. Unfortunately, no such classification exists.

The fruit size, which is correlating with fruit weight, has proved to be a very useful trait to distinguish the two main groups (Sativum and Microcarpum), which also differ by other characters such as length of vegetation period, plant height, branching, vegetative productivity and leaf characters. Recent investigations showed that the shape of the fruit is also important, and a third group (Indicum) with ovate fruits has been described. These three main groups also differ in content and composition of the essential oil of the fruit. A further distinction into 9 ecogeographical types (European, North African, Caucasian, Central Asian, Syrian, Ethiopian, Indian, Bhutanic and Omanic) within the 3 groups is possible, which reflects very well the evolutionary pathway of the species. Chemotaxonomical investigations support such infraspecific classification.

Ecology

Germination of coriander occurs at temperatures above 4 °C, but is optimal at 17-20 °C for genotypes with small fruits and at 22-27 °C for genotypes with larger fruits. Sowing is therefore possible at any time, provided that the water supply during the juvenile period is sufficient. After stem elongation coriander is sensitive to low temperatures but resistant to drought. Long days accelerate the generative development of coriander, but the effect is only minor. For successful fruit production the temperature sum during the vegetative period should be more than 1700°C and only high temperatures together with dry weather during ripening guarantee fruits of acceptable quality. Coriander for fruit production is found in tropical highlands, subtropics and temperate regions, while in the lowland tropics it is grown as a green herb. The soil should preferably be at least a sandy loam, but the crop will also grow well on loam and clay soils with good drainage. Sole cropping and intercropping, e.g. with legumes, are practised.

Propagation and planting

Coriander is propagated by seed. A heat treatment of the fruits after harvest or before sowing, either artificially or by exposure to the sun, will promote physiological ripening and break dormancy. Before sowing the fruits are sometimes split into mericarps, which enhances the germination rate and allows better distribution of the plants. For fruit production plant density should be 15-40 for small-seeded coriander, 75 plants per m² for large-seeded coriander, and even higher for the production of the green herb. In South-East Asia, the cultivation of coriander is limited to smallholders.

In vitro production of active compounds

In vitro culture of the callus derived from the root of coriander has been shown to contain geraniol; none of the other flavouring principles associated with the spice could be detected.

Husbandry

Weeding is carried out twice; the first weeding in the young crop is particularly important. When fruit production is the aim and heavy branching is developing, thinning is sometimes practised. Coriander is usually grown as a rain-fed crop, sometimes irrigation is applied during establishment. Phosphorus and potassium are often limiting nutrients, while the demand for nitrogen is not very high.

Diseases and pests

Seed-borne bacterial diseases can cause considerable losses, e.g. Pseudomonas syringae pv. coriandricola. Heat treatment or chemical disinfection of fruits is possible. Fungal diseases (Fusarium sp., Ramularia sp.) can be avoided by treating the fruits with a fungicide before sowing. In India, fruit damage is reported to be caused by the chalcid fly Systole albipennis. Pests like the biscuit beetle (Stegobium paniceum) may damage stored fruits.

Harvesting

For use as a green herb the entire, young plants are usually uprooted about 60 days after sowing. In the large-scale production of leaves in southern Russia, several cuts are possible if suitable genotypes are used. It is also possible to combine the harvest of fruits with some earlier cuts of leaves. For harvesting fruits, entire plants are uprooted or cut at the base when the fruits of the primary umbel are ripe and shatter when touched.

Due to the non-simultaneous ripening of the umbels of different order, plants are gathered in sheaves for further ripening and drying in the field. Threshing has to be done carefully, so that fruits do not split.

Yield

For use as a culinary herb fresh coriander yields of 24 t/ha have been reported. The yield of fruits can exceed 4 t/ha. Rainfed crops usually produce 400-700 kg/ha of fruits, irrigated crops usually 2 t/ha.

Handling after harvest

Split fruits are usually not accepted on the world market for medicinal purposes. Thoroughly dried fruits, stored under dry conditions, will maintain the essential oil for several years without loss. Once the fruits have been crushed, the essential oil will quickly disappear.

Genetic resources

Large collections of coriander germplasm exist in Russia, Germany and the United States. These cover a large part of the variation of Coriandrum sativum. Nevertheless, there are still geographical gaps in the collections, notably in local cultivars from the Middle East and from South-East Asia. Several local cultivars are at risk of genetic erosion.

Species of the tribe Coriandreae are potentially interesting genetic resources but, with the exception of the genus Bifora F. Hoffm., they are not represented in the collections. This even applies to the closest relative, Coriandrum tordylium (Fenzl.) Bornm. from the Near East.

Breeding

Considerable breeding has been conducted in East European countries and India. Coriander is a facultative cross-pollinator, with geitonogamy as the predominant mode of pollination. Many insects, including honey-bees, are involved in transferring the pollen. The main breeding objectives are high content of essential oil and disease resistance. In India, breeding has also focused on resistance to some pests. Hybridization with other species of the tribe Coriandreae (e.g. Bifora spp.) has so far not been successful.

Prospects

It is expected that the market for coriander as a culinary herb will increase in industrialized countries. However, the quality parameters for this use are still unknown, and the agronomic requirements have still to be established. At present, linalool derived from petrochemicals is cheaper than linalool distilled from coriander fruits, but consumer preference for the special qualities of natural flavours may bring about a shift in demand.

Literature

Alborisvili, C.A., 1971. Izmencivost' chozjajstvenno-biologiceskich osobennostej salata i koriandra v zavisimosti ot srokov poseva [Variability of economical and biological characters of lettuce and coriander cultivars in relation to sowing dates]. Trudy po prikladnoj botanike, genetike i selekcii 45: 216-227.
Diederichsen, A., 1996. Coriander. In: Heller, J., Engels, J. & Hammer, K. (Editors): Promoting the conservation and use of underutilized and neglected crops. Vol. 3. International Plant Genetic Resources Institute, Rome, Italy. 83 pp.
Ivanova, K.V. & Stoletova, E.A., 1990. Istorija kul'tury i vnutrividovaja klassifikacija koriandra posevnogo (Coriandrum sativum L.) [The history of culture and intraspecific taxonomy of Coriandrum sativum L.]. Sbornik naucnych trudov prikladnoj botbotaniki, genetiki i selekcii 133: 26-40.
Jansen, P.C.M., 1981. Spices, condiments and medicinal plants in Ethiopia, their taxonomy and agricultural significance. Centre for Agricultural Publishing and Documentation (Pudoc), Wageningen, the Netherlands. pp. 56-67.
Luk'janov, I.A. & Reznikov, A.R., 1976. Koriandr [Coriander]. In: Smoljanova, A.M. & Ksendza, A.T. (Editors): Efirnomaslicnye kul'tury. Kolos, Moskva, Russia. pp. 9-57
Palamarja, N.S. & Chotina, A.A. (Editors), 1953. Koriandr [Coriander]. Gosudarstvennoe izdatel'stvo sel'skochozjaistvennoj literatury. Moskva, Russia. 118 pp.
Potter, Th.L. & Fagerson, I.S., 1990. Composition of coriander leaf volatiles. Journal of Agricultural and Food Chemistry 38: 2054-2056.
The Wealth of India (various editors), 1948-1976. A dictionary of Indian raw materials and industrial products: raw materials. Vol. 2. Publications and Information Directorate, Council of Scientific and Industrial Research, New Delhi, India. pp. 347-350.
van Harten, A.M., 1974. Koriander: de geschiedenis van een oud gewas [Coriander: the history of an old crop]. Landbouwkundig Tijdschrift 86(3): 58-64.

Sources of illustrations

Jansen, P.C.M., 1981. Spices, condiments and medicinal plants in Ethiopia, their taxonomy and agricultural significance. Centre for Agricultural Publishing and Documentation (Pudoc), Wageningen, the Netherlands. Fig. 6, p. 59 (normal petal, fruit); Mansfeld, R., 1986. Verzeichnis landwirtschaftlicher und gärtnerischer Kulturpflanzen (ohne Zierpflanzen) [Register of agricultural and horticultural plants in cultivation (without ornamentals)]. Schultze-Motel, J. et al., editors 2nd edition. Vol. 2. Springer Verlag, Berlin, Germany. Fig. 138, pp. 996--997 (flowering branch, umbellet, peripheral flower with enlarged petals, central flower, fruiting branch, seed). Redrawn and adapted by P. Verheij-Hayes.

Authors

A. Diederichsen & Rugayah