Red onions (also known as purple or blue onions in some mainland European countries) are

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

s of the

onion An onion (''Allium cepa'' , from Latin ), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus '' Allium''. The shallot is a botanical variety of the onion which was classifie ...

('' Allium cepa''), and have purplish-red skin and white flesh tinged with red. They are most commonly used in cooking, but the skin has also been used as a

dye Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy Fantasy is a genre of speculative fiction that involves supernatural or Magic (supernatural), magical ele ...

. Red onions tend to be medium to large in size and have a sweeter flavor than

white White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wa ...

or yellow onions due to low levels of

pyruvic acid Pyruvic acid (CH3COCOOH) is the simplest of the keto acids, alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate acid, conjugate base, CH3COCOO−, is an metabolic intermediate, intermediate in several m ...

and

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

compounds. They are often consumed raw (and can be added to salads for color and bite), grilled, or lightly cooked with other foods. Red onions are available throughout the year and are high in

flavonoids Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

and

fiber Fiber (spelled fibre in British English; from ) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often inco ...

(compared to

and yellow onions).Bill Jones Cut red onion can be soaked in cool water for a period of time, and the water can be drained off, resulting in less "bite" and pungency.

Varieties

Tropea

The red onion from

Tropea Tropea (; ; ; ) is a municipality in the province of Vibo Valentia, in the Italian region of Calabria. It is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy"). Tropea is a seaside resort with sandy beaches, located on ...

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

, (Italian: "Cipolla Rossa di Tropea") grows in a small area of

Calabria Calabria is a Regions of Italy, region in Southern Italy. It is a peninsula bordered by the region Basilicata to the north, the Ionian Sea to the east, the Strait of Messina to the southwest, which separates it from Sicily, and the Tyrrhenian S ...

in southern Italy, Capo Vaticano, near the city of Tropea. This onion has a stronger and sweeter aroma and the inner part is juicier and whiter than other red onions and it is possible to make a jam with it. In July 2007, the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

registered the

Protected geographical indication Three European Union schemes of geographical indications and Traditional food, traditional specialties, known as protected designation of origin (PDO), protected geographical indication (PGI), and traditional speciality guaranteed (TSG), promote ...

mark for the red onions produced in this particular area in Italy.

Turda

The red onion from

Turda Turda (; , ; ; ) is a Municipiu, city in Cluj County, Transylvania, Romania. It is located in the southeastern part of the county, from the county seat, Cluj-Napoca, to which it is connected by the European route E81, and from nearby Câmpia ...

(

Cluj County Cluj County () is a county () of Romania, in Transylvania. Its seat is Cluj-Napoca. Name In Hungarian language, Hungarian it is known as ''Kolozs megye''. Under the Kingdom of Hungary, a county with an identical name (Kolozs County, ) existed s ...

, Central

Romania Romania is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to ...

) (Romanian: "Ceapa de Turda",) is a local variety of red onion with light sweeter taste and particular aroma. The area of cultivation encompass the lower

Arieș The Arieș () is a left tributary of the river Mureș in Transylvania, Romania. It discharges into the Mureș in Gura Arieșului, southwest of Luduș. Its total length (including its headwater Arieșul Mare) is , and its drainage basin area ...

valley and the middle Mureș valley. Turda onion bulbs are traditionally intertwined into long strings (1–2 m) for marketing purposes and can be found at the traditional markets all over central Romania. "Turda Red Onion" is usually served fresh, as a salad or part of mixed salads and especially as a compulsory garnish for the traditional bean-and-smoked ham soups.

Wethersfield

In the United States, one of the most prominent cultivars of red onion was grown in

Wethersfield, Connecticut Wethersfield ( ) is a town located in Hartford County, Connecticut, United States. It is located immediately south of Hartford along the Connecticut River. The town is part of the Capitol Planning Region. The population was 27,298 at the time ...

, and was a major source of onions for

New England New England is a region consisting of six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the ...

until the late 1800s.Wethersfield, CT, and Onions
, '' Yankee Magazine'', August 1993

References

External links

Onion Cultivation at the World Vegetable Center

{{Allium Onions Onion cultivars it:Cipolla rossa