Onion
51258
225618605
2008-07-14T16:11:13Z
213.10.173.29
/* Historical uses */
{{otheruses}}
{{redirect|Onions|the surname|Onions (surname)}}
{{Taxobox
| name = Onion
| image = Onions.jpg
| image_width = 240px
| image_caption = Onions
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Monocotyledon|Liliopsida]]
| ordo = [[Asparagales]]
| familia = [[Alliaceae]]
| genus = ''[[Allium]]''
| species = '''''A. cepa'''''
| binomial = ''Allium cepa''
| binomial_authority = [[Carolus Linnaeus|L.]]
}}[[Image:Onion on lettuce by Swatjester.jpg|thumb|right|Onion atop a bed of lettuce in a chicken sandwich.]][[Image:Organicsalsa.jpg||thumb|right|Onions used in [[Salsa (sauce)|salsa]].]][[Image:Muck onions 8640.jpg|right|thumb|Onion fields near [[Elba, New York]]]][[Image:Cooked onions in frying pan.JPG|thumb|Onions cooked in a [[frying pan]]]]
'''Onion''' is a term used for many plants in the genus ''[[Allium]]''. They are known by the common name "onion" but, used without qualifiers, it usually refers to '''''Allium cepa'''''. ''Allium cepa'' is also known as the ''''garden onion'''' or '[[bulb]]' onion and '[[shallot]]'.
''Allium cepa'' is known only in cultivation,<ref>{{cite web | url = http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200027457 | title = Allium cepa Linnaeus | work = Flora of North America }}</ref> but related wild species occur in Central Asia. The most closely-related species include ''Allium vavilovii'' Popov & Vved. and ''Allium asarense'' R.M. Fritsch & Matin from Iran.<ref name="prota">Grubben, G.J.H. & Denton, O.A. (2004) Plant Resources of Tropical Africa 2. Vegetables. PROTA Foundation, Wageningen; Backhuys, Leiden; CTA, Wageningen.</ref> However Zohary and Hopf warn that "there are doubts whether the ''vavilovii'' collections tested represent genuine wild material or only feral derivatives of the crop."<ref>Daniel Zohary and Maria Hopf, ''Domestication of plants in the Old World'', third edition (Oxford: University Press, 2000), p. 198</ref>
== Uses ==
Onions, one of the oldest vegetables known to humankind, are found in a bewildering array of recipes and preparations, spanning almost the totality of the world's cultures; they are nowadays available in fresh, frozen, canned, pickled, and dehydrated forms. Onions can be used, usually chopped or sliced, in almost every type of food, including cooked foods and fresh salads, and as a spicy garnish; they are rarely eaten on their own but usually act as accompaniment to the main course. Depending on the variety, an onion can be sharp, spicy, tangy and pungent or mild and sweet.
Onions pickled in vinegar are eaten as a snack. These are often served as a side serving in fish and chip shops throughout the [[United Kingdom]]. Onions are a [[staple food]] in [[India]], and are therefore fundamental to [[Indian cooking]]. They are commonly used as a base for [[curry|curries]], or made into a [[paste]] and eaten as a main course or as a side dish.
Tissue from onions is frequently used in [[science education]] to demonstrate [[microscope]] usage, because they have particularly large cells which are readily observed even at low magnifications.<ref>{{cite web
| date=2004-06-15
| accessdate=2008-01-28
| format=html
| url=http://genetics-education-partnership.mbt.washington.edu/class/elem.htm
| title=Genetics Teaching Vignettes: Elementary School
}}</ref>
== Historical uses ==
It is thought that bulbs from the onion family have been used as a food source for millennia. In Caananite [[Bronze Age]] settlements, traces of onion remains were found alongside [[fig]] and [[date palm|date]] stones dating back to 5000 BC.<ref name="selfsufficientish">{{cite web
|url=http://www.selfsufficientish.com/onion.htm
|title=Onions Allium cepa
|work=selfsufficientish.com
|accessdate=2006-04-02}}
</ref> Onion is native to [[South Asia]], and is widely used in [[India|Indian]] cuisine.<ref> Sen 2004: 58</ref>
However, it is not clear if these were cultivated onions. Archaeological and literary evidence such as the [[Book of Numbers]] 11:5 suggests cultivation probably took place around two thousand years later in [[ancient Egypt]], at the same time that [[Leek (vegetable)|leek]]s and [[garlic]] were cultivated. Workers who built the [[Egyptian pyramids]] may have been fed [[radish]]es and onions.<ref name="selfsufficientish"/>
The onion is easily propagated, transported and stored. The [[Ancient Egypt]]ians worshipped it,<ref name="onions-usa">{{cite web
| title=About Onions: History
| url=http://www.onions-usa.org/about/history.asp
| accessdate=2008-01-30
}}</ref> believing that its spherical shape and concentric rings symbolized eternal life. Onions were even used in Egyptian burials as evidenced by onion traces being found in the eye sockets of [[Ramesses IV]]. They believed that if buried with the dead, the strong scent of onions would bring breath back to the dead.
In ancient [[Greece]], athletes ate large quantities of onion because it was believed that it would lighten the balance of blood. Roman [[gladiator]]s were rubbed down with onion to firm up their muscles. In the [[Middle Ages]] onions were such an important food that people would pay for their rent with onions and even give them as gifts.<ref name="onions-usa"/> Doctors were known to prescribe onions to facilitate bowel movements and erection, and also to relieve headaches, coughs, [[snake]]bite and hair loss. The onion was introduced to [[North America]] by [[Christopher Columbus]] on his 1492 expedition to [[Haiti]]. Onions were also prescribed by doctors in the early 1500s to help with infertility in women, and even dogs and cattle and many other household pets. However, recent evidence has proven that dogs, cats, and other animals should NOT be given onions in any form, due to toxicity during digestion.
<ref name="petsonions">{{cite web
| title=Human Foods that Poison Pets
| url=http://www.petalia.com.au/Templates/StoryTemplate_Process.cfm?Story_No=257#ct-4
| accessdate=2008-01-30
}}</ref>
== Medicinal properties and health benefits ==
{{nutritionalvalue | name = Raw Onions | kJ=166 | carbs = 9.34 g | protein=1.1 g | fat= 0.1 g | satfat=0.042 g | monofat = 0.013 g | polyfat = 0.017 g | sugars=4.24 g | fiber = 1.7 g | thiamin_mg=0.046 | riboflavin_mg=0.027 | niacin_mg=0.116 | folate_ug=19 | vitA_ug = 0 | vitB6_mg=0.12 | vitB12_ug=0 | vitC_mg=7.4 | vitE_mg=0.02 | vitK_ug=0.4 | calcium_mg=23 | iron_mg=0.21 | magnesium_mg=0.129 | phosphorus_mg=29 | potassium_mg=146 | sodium_mg=4 | zinc_mg=0.17 | water=89.11 g | source_usda=1 | right=1}}
Wide-ranging claims have been made for the effectiveness of onions against conditions ranging from the common cold to heart disease, [[diabetes]], [[osteoporosis]], and other diseases.<ref>[http://www.whfoods.com/genpage.php?tname=foodspice&dbid=45 World's Healthiest Foods]</ref> They contain chemical compounds believed to have [[anti-inflammatory]], anticholesterol, anticancer, and [[antioxidant]] properties such as [[quercetin]]. However, it has not been demonstrated that increased consumption of onions is directly linked to health benefits.
In many parts of the world, onions are used to heal blisters and [[boils]]. A traditional [[Malta|Maltese]] remedy for [[sea urchin]] wounds is to tie half a baked onion to the afflicted area overnight. In the morning, the spikes will be in the onion.{{Fact|date=August 2007}} In the [[United States]], products that contain onion extract are used in the treatment of topical scars; some studies have found their action to be ineffective, <ref>
[http://dermatology.about.com/od/skincareproducts/gr/MedermaReview.htm Product Review: Mederma for Scars]</ref><ref>[http://linkinghub.elsevier.com/retrieve/pii/S1090820X05001093 Topical scar modification: Hype or help?. (Aesthetic Surgery Journal)]</ref><ref name="pmid17097399">{{cite journal | author=Zurada JM, Kriegel D, Davis IC | title=Topical treatments for hypertrophic scars. | journal=Journal of the American Academy of Dermatology | volume=55 | issue=6 | pages=1024–1031 | year=2006 | pmid=17097399 | doi=10.1016/j.jaad.2006.03.022}}</ref> while others found that they may act as an anti-inflammatory or bacteriostatic <ref name="augusti">K. Augusti, Therapeutic values of onion (Allium cepa L.) and garlic (Allium sativum L.), Indian J Exp Biol 34 (1996), pp. 634–640. </ref> and can improve collagen organization in rabbits.<ref name="pmid12087249">{{cite journal | author=Saulis, Alexandrina S. M.D.; Mogford, Jon H. Ph.D.; Mustoe, Thomas A. M.D. | title=Effect of Mederma on Hypertrophic Scarring in the Rabbit Ear Model | journal=Plastic and Reconstructive Surgery | volume=110 | issue=1 | pages=177–183 | year=2002 | pmid=12087249 | doi=10.1097/00006534-200207000-00029}}</ref>
Onions may be especially beneficial for women,<ref>{{cite web
| accessdate=2008-01-30
| title=Onion Compound May Help Fight Osteoporosis
| date=2005-04-11
| url=http://www.sciencedaily.com/releases/2005/04/050411112150.htm
| format=html
}}</ref> who are at increased risk for [[osteoporosis]] as they go through menopause, by destroying [[osteoclasts]] so that they do not break down bone.
== Onions and eye irritation ==
As onions are sliced, [[cell (biology)|cells]] are broken, allowing [[enzymes]] called [[alliinase]]s to break down [[amino acid]] [[sulphoxide]]s and generate [[sulphenic acid]]s. Sulphenic acids are unstable and spontaneously rearrange into a volatile [[gas]] called [[syn-propanethial-S-oxide]]. The gas diffuses through the air and eventually reaches the eye, where it reacts with the water to form a diluted solution of [[sulphuric acid]]. This acid irritates the [[nerve]] endings in the [[eye]], making them sting. Tear glands produce tears to dilute and flush out the irritant.<ref name="Sciam"> {{cite web
| last = Scott
| first = Thomas
| authorlink =
| coauthors =
| title = What is the chemical process that causes my eyes to tear when I peel an onion?
| work = Ask the Experts: Chemistry
| publisher = [[Scientific American]]
| date =
| url = http://www.sciam.com/askexpert_question.cfm?articleID=000C5FF7-5DB5-1C72-9EB7809EC588F2D7
| format =
| doi =
| accessdate = 2007-04-28}}
</ref>
Supplying ample water to the reaction while peeling onions prevents the gas from reaching the eyes. Eye irritation can, therefore, be avoided by cutting onions under running water or submerged in a basin of water. Rinsing the onion and leaving it wet while chopping may also be effective. Another way to avoid irritation is by not cutting off the root of the onion, or by doing it last, as the root of the onion has a higher concentration of enzymes.<ref>[http://www.onions-usa.org/about/faq.asp#cooking Onions-USA.org FAQ]</ref> Using a sharp blade to chop onions will limit the cell damage and the release of enzymes that drive the irritation response. (Having a sharp knife and keeping the root of a halved onion on until the end also reduces the risk of cutting one's self if the knife slips). Chilling or freezing onions prevents the enzymes from activating, limiting the amount of gas generated. Having a fire, such as a candle or a burner, will help as the heat and flames will draw in the onion gas, burn it, and then send it up with the rest of the flame exhaust.{{Fact|date=November 2007}} In the heat, the chemical changes such that it no longer irritates the eyes.{{Fact|date=November 2007}}
The volume of sulfenic acids released, and the irritation effect, differs among ''Allium'' species.
On [[January 31]], [[2008]], the [[New Zealand]] Crop and Food institute led by Colin Eady created 'no tears' onions by using Australian [[gene]]-silencing [[biotechnology]].<ref>[http://www.news.com.au/story/0,23599,23144566-23109,00.html news.com.au, Scientists create 'no tears' onions]</ref>
== Propagation ==
[[Image:2005onion and shallot.PNG|thumb|right|Onion and [[shallot]] output in 2005]]
[[Image:Onion whitebackground.jpg|thumb|Onion growing shoots]]
Onions may be grown from seed or, more commonly today, from sets started from seed the previous year. Onion sets are produced by sowing seed very thickly one year, resulting in stunted plants which produce very small bulbs. These bulbs are very easy to set out and grow into mature bulbs the following year, but they have the reputation of producing a less durable bulb than onions grown directly from seed and thinned.
Seed-bearing onions are day-length sensitive; their bulbs begin growing only after the number of daylight hours has surpassed some minimal quantity. Most traditional European onions are what is referred to as "long-day" onions, producing bulbs only after 15+ hours of daylight occur. Southern European and north African varieties are often known as "intermediate day" types, requiring only 12-13 hours of daylight to stimulate bulb formation. Finally, "short-day" onions, which have been developed in more recent times, are planted in mild-winter areas in the fall and form bulbs in the early spring, requiring only 9-10 hours of sunlight to stimulate bulb formation.
Either planting method may be used to produce spring onions or green onions, which are the leaves and/or immature plants. Green onion is a name also used to refer to another species, ''Allium fistulosum'', the [[Welsh onion]], which is said not to produce dry bulbs.
== Varieties ==
<gallery>
Image:Two colors of onions.jpg|Brown and white onions
Image:YellowOnions.jpg|[[Yellow onion|Yellow Onions]]
Image:Onion Flower Head.jpg|Flower head of a yellow onion
Image:ARS_red_onion.jpg|[[Red onion]]s
</gallery>
*Bulb onion - Grown from seed (or onion sets), bulb onions range from the pungent varieties used for dried soups and onion powder to the mild and hearty [[sweet onion]]s, such as the [[Vidalia onion|Vidalia]] from Georgia or Walla Walla from Washington that can be sliced and eaten on a sandwich instead of meat.
*Multiplier onions - Raised from bulbs which produce multiple shoots, each of which forms a bulb.
**[[Potato onion]]
*[[Tree onion]] or Egyptian onion - Produce bulblets in the flower head; a [[Hybrid (biology)|hybrid]] of ''Allium cepa''s.
*[[Welsh onion]] or Green onion
**[[Leek]]
Shallots and ten other onion (Allium cepa L.) varieties commonly available in the United States were evaluated: Western Yellow, Northern Red, New York Bold, Western White, Peruvian Sweet, Empire Sweet, Mexico, Texas 1015, Imperial Valley Sweet, and Vidalia. In general, the most pungent onions delivered many times the benefits of their milder cousins.<ref name="cornellnews" >{{cite web
| date=2004-10-07
| accessdate=2008-01-30
| format=hmtl
| title=Onion a day keeps doctor away?
| url=http://www.news.cornell.edu/releases/Oct04/onions.cancer.ssl.html
| publisher=Cornell University
}}</ref>
Shallots have the most [[phenol]]s, six times the amount found in Vidalia onion, the variety with the lowest phenolic content. Shallots also have the most [[antioxidant]] activity, followed by Western Yellow, New York Bold, Northern Red, Mexico, Empire Sweet, Western White, Peruvian Sweet, Texas 1015, Imperial Valley Sweet, and Vidalia. Western Yellow onions have the most [[flavonoid]]s, eleven times the amount found in Western White, the variety with the lowest flavonoid content.
For all varieties of onions, the more phenols and flavonoids they contain, the more antioxidant and anti-cancer activity they provide. When tested against liver and colon cancer cells, Western Yellow, New York Bold and shallots were most effective in inhibiting their growth. The milder-tasting varieties—Western White, Peruvian Sweet, Empire Sweet, Mexico, Texas 1015, Imperial Valley Sweet, and Vidalia—showed little cancer-fighting ability.<ref name="cornellnews"/>
==Production trends==
{| class="wikitable" align=left style="clear:left"
! colspan=2|Top Ten Onions Producers — 2005<br>(1000 tonnes)
|-
| {{CHN}} || align="right" | 19,793
|-
| {{IND}} || align="right" | 5,500
|-
| {{USA}} || align="right" | 3,346
|-
| {{TUR}} || align="right" | 2,220
|-
| {{PAK}} || align="right" | 1,764
|-
| {{RUS}} || align="right" | 1,758
|-
| {{KOR}}|| align="right" | 1,750
|-
| {{JPN}} || align="right" | 1,637
|-
| {{EGY}} || align="right" | 1,302
|-
| {{ESP}} || align="right" | 1,149
|-
|'''World Total''' || align="right" | '''64,101'''
|-
|colspan=2|''Source: <br>[[UN Food & Agriculture Organisation]] (FAO)''[http://faostat.fao.org/site/340/default.aspx]
|}
{{clear}}
== Onions in language ==
In the [[English language|English]] vernacular, "an onion" is a difficult situation, the use stemming from the onion's tendency to irritate or inflame the [[eyes]]. Conversely, the term "onion" can be used to describe any state of being, as in the phrase, "[someone] really dices my onion!" It may also represent an object of many layers.
When someone is very skilled or has a great deal of knowledge about a particular subject, it is sometimes said that they "know their onions".
In some Scots dialects, onion is pronounced 'Ingin'.
An "Onion" is also an old slang term to describe a person from Bermuda; a Bermudian.
Bermuda is known to sprout some of best onions in the world, that is why they're (Bermudians) called "onions".
In [[French]], the expression "Ce n'est pas tes oignons" (That is not your onions) means that a topic is none of the listener's business.
Feminist poet [[Carol Ann Duffy]] uses the onion as a metaphor of love and relationships in her poem "Valentine" (1993), one of the poems in her collection "Mean time"
Expressions referring to "layers of the onion" evoke the process of peeling back the layers of something (a person, reality, etc.), without however reaching a core - the centre of the onion being simply another layer. The metaphor is thus used to challenge the notion that there is a core/essence 'behind' surface layers, stressing the continuity between layer and core. Due to the number of layers in an onion it can also be used simply to evoke complexity - something having 'many layers', or 'always another layer behind this one".
This idea was used (& twisted) in the first ''[[Shrek]]'' movie, ([[Dreamworks]] LLC), when Shrek tries to explain to his partner, Donkey, that he is a complex person by telling him that 'Ogres are like onions.' (meaning that they have layers), to which Donkey replies 'Oh I get it. You leave them out in the sun too long and they go all brown and start sprouting little white hairs!'
{{Commons|Allium cepa}}
In other languages too the onion has acquired different connotations, eg., amongst the Khasi tribe in North East India, Onion or "piat" in the local dialect refers to someone who is present everywhere or in every social gathering.
== Notes ==
{{Reflist}}
==References==
* Sen, Colleen T. (2004). ''Food culture in India''. Greenwood Publishing. ISBN 0313324875.
== See also ==
*{{cite web| last=Barbagallo|first=Tricia|url=http://www.archives.nysed.gov/apt/magazine/MagSummer05FeatureArticle_000.pdf|title=Black Beach: The Mucklands of Canastota, New York|date=[[June 01]], [[2005]]|accessdate=2008-06-04}}
*[[Onion Johnny]]
*A comic song has been recorded by UK comedy pop group The Badger Famine based entirely on this site's 'Historical Uses' paragraph. Lyrics can be found here: http://www.thebadgerfamine.co.uk/finestbulb.html
== External links ==
*[http://database.prota.org/dbtw-wpd/exec/dbtwpub.dll?AC=QBE_QUERY&BU=http%3A%2F%2Fdatabase.prota.org%2Fsearch.htm&TN=PROTAB~1&QB0=AND&QF0=Species+Code&QI0=Allium+cepa&RF=Webdisplay PROTAbase on ''Allium cepa'']
*[http://www.rachaelraymag.com/cooking-tips/step-by-step-video---how-to-cut-an-onion/article.html How to safely cut an onion (by Rachael Ray)]
*[http://members.aol.com/stevef88/discuss/onions.htm The Secret to Cutting Onions Without Crying (by Steve Fry)]
*[http://video.about.com/southernfood/No-Cry-Onion-Chopping.htm Watch the Video: No Cry Onion Chopping (with Jonathon Stewart)]
*[http://www.brokenearth.org/cancer Medicinal Pungent Onions]
[[Category:Allium]]
[[Category:Medicinal plants]]
[[Category:Onions| ]]
[[Category:Root vegetables]]
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