Cloves are the aromatic flower bud
s of a tree in the family Myrtaceae
, ''Syzygium aromaticum''. They are native to the Maluku Islands
(or Moluccas) in Indonesia
, and are commonly used as a spice
Cloves are available throughout the year owing to different harvest seasons in different countries.
The clove tree is an evergreen
that grows up to tall, with large leaves and crimson
flowers grouped in terminal clusters. The flower buds initially have a pale hue, gradually turn green, then transition to a bright red when ready for harvest. Cloves are harvested at long, and consist of a long calyx
that terminates in four spreading sepal
s, and four unopened petals that form a small central ball.
Cloves are used in the cuisine of Asian
, and the Near
and Middle East
countries, lending flavor to meats, curries
, and marinade
s, as well as fruit (such as apples, pears, and rhubarb
). Cloves may be used to give aromatic and flavor qualities to hot beverages, often combined with other ingredients such as lemon and sugar. They are a common element in spice blends, including pumpkin pie spice
In Mexican cuisine
, cloves are best known as ''clavos de olor'', and often accompany cumin
. They are also used in Peruvian cuisine, in a wide variety of dishes such as ''carapulcra
'' and ''arroz con leche
A major component of clove taste is imparted by the chemical eugenol
and the quantity of the spice required is typically small. It pairs well with cinnamon, allspice
, red wine
, citrus peel
, star anise
, and peppercorn
The spice is used in a type of cigarette called ''kretek
'' in Indonesia.
Clove cigarettes have been smoked throughout Europe, Asia, and the United States. Since 2009, clove cigarettes have been classified as cigars in the US.
Because of the bioactive chemicals of clove, the spice may be used as an ant repellent.
Cloves can be used to make a fragrant pomander
when combined with an orange. When given as a gift in Victorian England, such a pomander indicated warmth of feeling.
Potential medicinal uses and adverse effects
Long-used in traditional medicine
, there is evidence that clove oil containing eugenol
is effective for toothache
pain and other types of pain,
and one review reported efficacy of eugenol combined with zinc oxide
as an analgesic
for alveolar osteitis
. Studies to determine its effectiveness for fever reduction, as a mosquito
repellent, and to prevent premature ejaculation
have been inconclusive.
[ It remains unproven whether blood sugar levels are reduced by cloves or clove oil.] [ Use of clove for any medicinal purpose has not been approved by the US Food and Drug Administration, and its use may cause adverse effects if taken orally by people with liver disease, blood clotting and immune system disorders, or food allergies.] [
Traditional medicinal uses
Cloves are used in traditional medicine as the essential oil, which is used as an anodyne (analgesic) mainly for dental emergencies and other disorders. The essential oil is used in aromatherapy.
Clove stalks are slender stems of the inflorescence axis that show opposite decussate branching. Externally, they are brownish, rough, and irregularly wrinkled longitudinally with short fracture and dry, woody texture.
Mother cloves (anthophylli) are the ripe fruits of cloves that are ovoid, brown berries, unilocular and one-seeded.
Blown cloves are expanded flowers from which both corollae and stamens have been detached.
Exhausted cloves have most or all the oil removed by distillation. They yield no oil and are darker in color.
Evidence of cloves has been found at Terqa, Syria dating to 1720 BCE In the third century BC, Chinese emperors of the Han Dynasty required those who addressed them to chew cloves to freshen their breath. Cloves reached the Roman world by the first century AD, where they were described by Pliny the Elder.
By 176 AD, cloves had reached Egypt.
The first clearly dated archeological find of a clove is substantially later than the written evidence, with two examples found at a trading port in Sri Lanka, dated to around 900-1100 AD.
Cloves were traded by Omani sailors and merchants trading goods from India to the mainland and Africa during the Middle Ages in the profitable Indian Ocean trade.
Until modern times, cloves grew only on a few islands in the Moluccas (historically called the Spice Islands), including Bacan, Makian, Moti, Ternate, and Tidore. In fact, the clove tree that experts believe is the oldest in the world, named ''Afo'', is on Ternate; the tree is between 350 and 400 years old. Tourists are told that seedlings from this very tree were stolen by a Frenchman named Pierre Poivre in 1770, transferred to the Isle de France (Mauritius), and then later to Zanzibar, which was once the world's largest producer of cloves.
Until cloves were grown outside of the Maluku Islands, they were traded like oil, with an enforced limit on exportation. As the Dutch East India Company consolidated its control of the spice trade in the 17th century, they sought to gain a monopoly in cloves as they had in nutmeg. However, "unlike nutmeg and mace, which were limited to the minute Bandas, clove trees grew all over the Moluccas, and the trade in cloves was beyond the limited policing powers of the corporation."
Eugenol comprises 72–90% of the essential oil extracted from cloves, and is the compound most responsible for clove aroma.
Complete extraction occurs at 80 minutes in pressurized water at . Ultrasound-assisted and microwave-assisted extraction methods provide more rapid extraction rates with lower energy costs.
Other important essential oil constituents of clove oil include acetyl eugenol, beta-caryophyllene, vanillin, crategolic acid, tannins such as bicornin, gallotannic acid, methyl salicylate (painkiller), the flavonoids eugenin, kaempferol, rhamnetin, and eugenitin, triterpenoids such as oleanolic acid, stigmasterol, and campesterol and several sesquiterpenes. [''Chinese Herbal Medicine: Materia Medica'', Third Edition by Dan Bensky, Steven Clavey, Erich Stoger, and Andrew Gamble. 2004] Eugenol has not been classified for its potential toxicity. [
* ''Cinnamomum cassia''
* Gallic acid
* Insect repellent
* Medicinal plant
Category:Flora of the Maluku Islands
Category:Plants used in Ayurveda
Category:Plants used in traditional Chinese medicine
Category:Non-timber forest products
Category:Taxa named by Elmer Drew Merrill