Clove

This article is about the spice; for other meanings see clove (disambiguation).

Cloves (Syzygium aromaticum, syn. Eugenia aromaticum or Eugenia caryophyllata) are the aromatic dried flower buds of a tree in the family Myrtaceae. It is native to Indonesia and used as a spice in cuisine all over the world. The name derives from French clou, a nail, as the buds vaguely resemble small irregular nails in shape. Cloves are harvested primarily in Zanzibar, Indonesia and Madagascar; it is also grown in Pakistan, India, and Sri Lanka.

The clove tree is an evergreen which grows to a height ranging from 10-20 m, having large oval leaves and crimson flowers in numerous groups of terminal clusters. The flower buds are at first of a pale color and gradually become green, after which they develop into a bright red, when they are ready for collecting. Cloves are harvested when 1.5-2 cm long, and consist of a long calyx, terminating in four spreading sepals, and four unopened petals which form a small ball in the centre.

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Uses

According to FAO, Indonesia produced almost 80% of the world's clove output in 2005 followed at a distance by Madagascar and Tanzania.

Cloves can be used in cooking either whole or in a ground form, but as they are extremely strong, they are used sparingly. The spice is used throughout Europe and Asia and is smoked in a type of cigarettes locally known as kretek in Indonesia. Cloves are also an important incense material in Chinese and Japanese culture.

Cloves have historically been used in Indian cuisine (both North Indian and South Indian) as well as in Mexican cuisine, where it is often paired together with cumin and canela (cinnamon).^[1] In the north Indian cuisine, it is used in almost every sauce or side dish made, mostly ground up along with other spices. They are also a key ingredient in tea along with green cardamoms. In the south Indian cuisine, it finds extensive use in the biryani dish (similar to the pilaf, but with the addition of local spice taste), and is normally added whole to enhance the presentation and flavor of the rice.

Medicinal uses

Cloves are used in Ayurveda, Chinese medicine and western herbalism and dentistry where the essential oil is used as an anodyne for dental emergencies. Cloves are used as a carminative, to increase hydrochloric acid in the stomach and to improve peristalsis. Cloves are also said to be a natural antihelmintic.^[2] The essential oil is used in aromatherapy when stimulation and warming is needed, especially for digestive problems. Topical application over the stomach or abdomen will warm the digestive tract.

In Chinese medicine cloves or ding xiang are considered acrid, warm and aromatic, entering the kidney, spleen and stomach channels, and are notable in their ability to warm the middle, direct stomach qi downward, to treat hiccough and to fortify the kidney yang.^[3] Because the herb is so warming it is contraindicated in any persons with fire symptoms and according to classical sources should not be used for anything except cold from yang deficiency. As such it is used in formulas for impotence or clear vaginal discharge from yang deficiency, for morning sickness together with ginseng and patchouli, or for vomiting and diarrhea due to spleen and stomach coldness.^[4] This would translate to hypochlorhydria. (Note that capitalized organ names refer to the Chinese meridians named after them.)

Ayurvedic herbalist K.P. Khalsa, RH (AHG), uses cloves internally as a tea and topically as an oil for hypotonic muscles, including for multiple sclerosis. This is also found in Tibetan medicine.^[5] Ayurvedic herbalist Alan Tilotson, RH (AHG) suggests avoiding more than occasional use of cloves internally in the presence of pitta inflammation such as is found in acute flares of autoimmune diseases.^[6]

Toxicity

Large amounts should be avoided in pregnancy. Cloves can be irritating to the gastrointestinal tract, and should be avoided by people with gastric ulcers, colitis, or irritable bowel syndrome. In overdoses, cloves can cause vomiting, nausea, diarrhea, and upper gastrointestinal hemorrhage. Severe cases can lead to changes in liver function, dyspnea, loss of consciousness, hallucination, and even death.^[7] The internal use of the essential oil should be restricted to 3 drops per day for an adult as excessive use can cause severe kidney damage.

History

Until modern times, cloves grew only on a few islands in the Maluku Islands (historically called the Spice Islands), including Bacan, Makian, Moti, Ternate, and Tidore.^[8] Nevertheless, they found their way west to the Middle East and Europe well before the time of Christ. Archeologists found cloves within a ceramic vessel in Syria along with evidence dating the find to within a few years of 1721 BC.^[8]

Cloves, along with nutmeg and pepper, were highly prized in Roman times, and Pliny the Elder once famously complained that "there is no year in which India does not drain the Roman Empire of fifty million sesterces". Cloves were traded by Arabs during the Middle Ages in the profitable Indian Ocean trade. In the late fifteenth century, Portugal took over the Indian Ocean trade, including cloves, due to the Treaty of Tordesillas with Spain and a separate treaty with the sultan of Ternate. The Portuguese brought large quantities of cloves to Europe, mainly from the Maluku Islands. Clove was then one of the most valuable spices, a kg costing around 7 g of gold^{[citation needed]}.

The trade later became dominated by the Dutch in the seventeenth century. With great difficulty the French succeeded in introducing the clove tree into Mauritius in the year 1770; subsequently their cultivation was introduced into Guiana, Brazil, most of the West Indies, and Zanzibar, where the majority of cloves are grown today.

In Britain in the seventeenth and eighteenth centuries, cloves were worth at least their weight in gold, due to the high price of importing them.^{[citation needed]}

The clove has become a commercial 'success', with products including clove drops being released and enjoyed by die-hard clove fans.

Active compounds

The compound responsible for the cloves' aroma is eugenol. It is the main component in the essential oil extracted from cloves, comprising 72-90%. Eugenol has pronounced antiseptic and anaesthetic properties. Other important constituents include essential oils acetyl eugenol, beta-caryophylline and vanillin; crategolic acid; tannins, gallotannic acid, methyl salicylate (painkiller); the flavanoids eugenin, kaempferol, rhamnetin, and eugenitin; triterpenoids like oleanolic acid, stigmasterol and campesterol; and several sesquiterpenes.^[9]

Notes and references

1. ^ Dorenburg, Andrew and Page, Karen. "The New American Chef: Cooking with the Best Flavors and Techniques from Around the World", John Wiley and Sons Inc., ©2003.
2. ^ Balch, Phyllis and Balch, James. Prescription for Nutritional Healing, 3rd ed., Avery Publishing, ©2000, pg. 94.
3. ^ Chinese Herbal Medicine: Materia Medica, Third Edition by Dan Bensky, Steven Clavey, Erich Stoger, and Andrew Gamble 2004
4. ^ Chinese Herbal Medicine: Materia Medica, Third Edition by Dan Bensky, Steven Clavey, Erich Stoger, and Andrew Gamble 2004
5. ^ http://www.tibetmed.org/questions/question_44.htm
6. ^ http://oneearthherbs.squarespace.com/diseases/special-diets-for-illness.html Tilotson, Alan. Special Diets for Illness
7. ^ Chinese Herbal Medicine: Materia Medica, Third Edition by Dan Bensky, Steven Clavey, Erich Stoger, and Andrew Gamble 2004
8. ^ ^{a b} Turner, Jack (2004). Spice: The History of a Temptation. Vintage Books, p. xv. ISBN 0-375-70705-0. 
9. ^ Chinese Herbal Medicine: Materia Medica, Third Edition by Dan Bensky, Steven Clavey, Erich Stoger, and Andrew Gamble. 2004