Red onions (also known as purple or blue onions in some mainland European countries, though not the UK) are

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

s of the

onion An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), 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 ...

(''

Allium cepa An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), 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 ...

''), 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 A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution an ...

. Red onions tend to be medium to large in size and have a sweeter flavor than white or yellow onions due to low levels of

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

and

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

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 or fibre (from la, fibra, links=no) 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 incorporate ...

(compared to white 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 (; scn, label= Calabrian, Trupìa; la, Tropaea; grc, Τράπεια, Trápeia) is a municipality in the province of Vibo Valentia, in Calabria, Italy. Tropea is a seaside resort with sandy beaches, located on the Gulf of Saint Euphemi ...

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...

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

Calabria , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...

in southern Italy,

Capo Vaticano Capo Vaticano is a wide bathing place in the Municipality of Ricadi in Calabria, Italy. The 'Cape' is formed by a particular white-gray granite, which is examined worldwide for its geologic characteristics. Geography The maximum altitude of the c ...

, 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 Jam is a type of fruit preserve. Jam or Jammed may also refer to: Other common meanings * A firearm malfunction * Block signals ** Radio jamming ** Radar jamming and deception ** Mobile phone jammer ** Echolocation jamming Arts and entertai ...

with it. In March 2008, the

European Union The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been des ...

registered the

Protected Designation of Origin The protected designation of origin (PDO) is a type of geographical indication of the European Union and the United Kingdom aimed at preserving the designations of origin of food-related products. The designation was created in 1992 and its main ...

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

Turda

The red onion from

Turda Turda (; hu, Torda, ; german: link=no, Thorenburg; la, Potaissa) is a 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 Europe ...

(

Cluj County Cluj County (; german: Kreis Klausenburg, hu, Kolozs megye) is a county ( județ) of Romania, in Transylvania. Its seat ( ro, Oraș reședință de județ) is Cluj-Napoca (german: Klausenburg). Name In Hungarian, it is known as ''Kolozs megye ...

, Central

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...

) (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 ( hu, Aranyos) 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 ba ...

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. It is located immediately south of Hartford along the Connecticut River. Its population was 27,298 at the time of the 2020 census. Many records from colonial times spell the name ...

, and was a major source of onions for

New England New England is a region comprising 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 to the west and by the Canadian provinces ...

until the late 1800s.Wethersfield, CT, and Onions
, ''

Yankee Magazine ''Yankee'' is a bimonthly (once every two months) magazine about lifestyle, travel and culture in the New England region of the United States, based in Dublin, New Hampshire. The first issue appeared in September 1935. It has a paid circulation ...

'', August 1993

References

External links

Onion Cultivation at the World Vegetable Center

{{Allium Onions Onion cultivars it:Cipolla rossa