Kale (), or leaf cabbage, belongs to a group of cabbage (''

Brassica oleracea ''Brassica oleracea'' is a plant species from family Brassicaceae that includes many common cultivars used as vegetables, such as cabbage, broccoli, cauliflower, kale, Brussels sprouts, collard greens, Savoy cabbage, kohlrabi, and gai lan. ...

'')

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 grown for their edible leaves, although some are used as

ornamentals Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

. Kale plants have green or purple leaves, and the central leaves do not form a head (as with

headed cabbage Cabbage, comprising several cultivars of ''Brassica oleracea'', is a leafy green, red (purple), or white (pale green) biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage ( ''B.&nbs ...

). Kales are considered to be closer to wild cabbage than most of the many domesticated forms of ''Brassica oleracea''.

Etymology

''Kale'' originates from Northern

Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English ...

''cale'' (compare Scots ''kail'' and German ''Kohl'') for various cabbages. The ultimate origin is

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''caulis'' 'cabbage'.

History

Kale originated in the eastern Mediterranean and

Anatolia Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The ...

, where it was cultivated for food beginning by 2000 BCE at the latest. Curly-leaved varieties of cabbage already existed along with flat-leaved varieties in

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders ...

in the 4th century BC. These forms, which were referred to by the

Romans Roman or Romans most often refers to: *Rome, the capital city of Italy * Ancient Rome, Roman civilization from 8th century BC to 5th century AD *Roman people, the people of ancient Rome *''Epistle to the Romans'', shortened to ''Romans'', a lette ...

as Sabellian kale, are considered to be the ancestors of modern kales. The earliest record of cabbages in western Europe is of hard-heading cabbage in the 13th century. Records in 14th-century England distinguish between hard-heading cabbage and loose-leaf kale. Russian traders introduced Russian kale into Canada and then into the United States in the 19th century.

USDA The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...

botanist

David Fairchild David Grandison Fairchild (April 7, 1869 – August 6, 1954) was an American botanist and plant explorer. Fairchild was responsible for the introduction of more than 200,000 exotic plants and varieties of established crops into the United State ...

is credited with introducing kale (and many other crops) to Americans, having brought it back from

Croatia , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = "Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capit ...

, although Fairchild himself disliked cabbages, including kale. At the time, kale was widely grown in Croatia mostly because it was easy to grow and inexpensive, and could desalinate soil. For most of the twentieth century, kale was primarily used in the United States for decorative purposes; it became more popular as an edible vegetable in the 1990s due to its nutritional value. During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

, the cultivation of kale (and other vegetables) in the U.K. was encouraged by the

Dig for Victory Victory gardens, also called war gardens or food gardens for defense, were vegetable, fruit, and herb gardens planted at private residences and public parks in the United States, United Kingdom, Canada, Australia and Germany during World War I ...

campaign. The vegetable was easy to grow and provided important nutrients missing from a diet because of

rationing Rationing is the controlled distribution of scarce resources, goods, services, or an artificial restriction of demand. Rationing controls the size of the ration, which is one's allowed portion of the resources being distributed on a particular ...

Cultivation

Kale is usually an annual plant grown from seed with a wide range of germination temperatures. It is hardy and thrives in wintertime, and can survive in temperatures as low as –15.0° Celsius.Derek B. Munro Kale can become sweeter after a heavy frost.

Cultivars

One may differentiate between kale varieties according to the low, intermediate, or high length of the stem, along with the variety of leaf types. The leaf colours range from light green to green, dark green, violet-green, and violet-brown. Classification by leaf type: * Curly-leaf (Scots kale, blue curled kale) * Bumpy-leaf (black cabbage, better known by its Italian translation 'cavolo nero', and also known as Tuscan Cabbage, Tuscan Kale, lacinato and dinosaur kale) * Plain-leaf (flat-leaf types like red Russian and white Russian kale) * Leaf and spear, or feathery-type leaf (a cross between curly- and plain-leaf) *Ornamental (less palatable and tougher leaves) Ornamental Kale

Because kale can grow well into winter, one variety of ''rape kale'' is called "''

hungry gap In cultivation of vegetables in a temperate oceanic climate, the hungry gap is the period in spring when there is little or no fresh produce available from a vegetable garden or allotment. It usually starts when overwintered brassica vegetables suc ...

"'' after the period in winter in traditional agriculture when little else could be harvested. An extra-tall variety is known as ''

Jersey kale The Jersey cabbage (''Brassica oleracea longata'') is a variety of cabbage native to the Channel Islands that grows to a great height and was formerly commonly used there as livestock fodder and for making walking sticks. It is also known as Jer ...

'' or ''cow cabbage''. ''

Kai-lan Gai lan, kai-lan, Chinese broccoli, Chinese kale, or jie lan (''Brassica oleracea'' var. ''alboglabra'') is a leaf vegetable with thick, flat, glossy blue-green leaves with thick stems, and florets similar to (but much smaller than) broccoli. ...

'' or ''Chinese kale'' is a cultivar often used in Chinese cuisine. In Portugal, the bumpy-leaved kale is mostly called "couve galega" (Galician kale or Portuguese Cabbage).

Ornamental kale

Many varieties of kale and cabbage are grown mainly for ornamental leaves that are brilliant white, red, pink, lavender, blue, or violet in the interior of the rosette. The different types of ornamental kale are peacock kale, coral prince, kamone coral queen, color up kale, and chidori kale. ''Ornamental kale'' is as edible as any other variety, but potentially not as

palatable Palatability (or palatableness) is the hedonic reward (i.e., pleasure) provided by foods or fluids that are agreeable to the "palate", which often varies relative to the homeostatic satisfaction of nutritional, water, or energy needs. The palatabi ...

. Kale leaves are increasingly used as an ingredient for vegetable bouquets and wedding bouquets.

Nutritional value

Raw kale is composed of 84% water, 9% carbohydrates, 4%

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

, and 1%

fat In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food. The term often refers specifically to triglycerides (triple est ...

(table). In a serving, raw kale provides of

food energy Food energy is chemical energy that animals (including humans) derive from their food to sustain their metabolism, including their muscular activity. Most animals derive most of their energy from aerobic respiration, namely combining the carbohy ...

and a large amount of

vitamin K Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-synthesis modification of certain proteins that are required for blood coagulation ...

at 3.7 times the

Daily Value The Reference Daily Intake (RDI) used in nutrition labeling on food and dietary supplement products in the U.S. and Canada is the daily intake level of a nutrient that is considered to be sufficient to meet the requirements of 97–98% of healthy ...

(DV) (table). It is a rich source (20% or more of the DV) of

vitamin A Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably ...

vitamin C Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) ...

vitamin B6 Vitamin B6 is one of the B vitamins, and thus an essential nutrient. The term refers to a group of six chemically similar compounds, i.e., " vitamers", which can be interconverted in biological systems. Its active form, pyridoxal 5′-phosp ...

folate Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing an ...

, and

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

(see table "Kale, raw"). Kale is a good source (10–19% DV) of

thiamin Thiamine, also known as thiamin and vitamin B1, is a vitamin, an essential micronutrient, that cannot be made in the body. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of t ...

, riboflavin,

pantothenic acid Pantothenic acid, also called vitamin B5 is a water-soluble B vitamin and therefore an essential nutrient. All animals require pantothenic acid in order to synthesize coenzyme A (CoA) – essential for fatty acid metabolism – as well as to, ...

vitamin E Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vi ...

, and several

dietary minerals In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life. However, the four major structural elements in the human body by weight (oxygen, hydrogen, carbon, ...

, including

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosph ...

, and

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

(see table "Kale, raw"). Boiling raw kale diminishes most of these nutrients, while values for vitamins A, C, and K and manganese remain substantial (see table "Kale, cooked").

Phytochemicals

Kale is a source of the carotenoids,

lutein Lutein (;"Lutein"

zeaxanthin Zeaxanthin is one of the most common carotenoids in nature, and is used in the xanthophyll cycle. Synthesized in plants and some micro-organisms, it is the pigment that gives paprika (made from bell peppers), corn, saffron, goji ( wolfberries ...

(tables). As with

broccoli Broccoli (''Brassica oleracea'' var. ''italica'') is an edible green plant in the cabbage family (family Brassicaceae, genus ''Brassica'') whose large flowering head, stalk and small associated leaves are eaten as a vegetable. Broccoli is cla ...

and other

cruciferous vegetable Cruciferous vegetables are vegetables of the family Brassicaceae (also called Cruciferae) with many genera, species, and cultivars being raised for food production such as cauliflower, cabbage, kale, garden cress, bok choy, broccoli, Brussels spr ...

s, kale contains glucosinolate compounds, such as

glucoraphanin Glucoraphanin is a glucosinolate found in broccoli, mustard and other cruciferous vegetables. Glucoraphanin is converted to sulforaphane by the enzyme myrosinase. In plants, sulforaphane deters insect predators and acts as a selective antibioti ...

, which contributes to the formation of

sulforaphane Sulforaphane (sometimes sulphoraphane in British English) is a compound within the isothiocyanate group of organosulfur compounds. It is produced when the enzyme myrosinase transforms glucoraphanin, a glucosinolate, into sulforaphane upon damage ...

, a compound under preliminary research for its potential to affect human health beneficially. Boiling kale decreases the level of glucosinate compounds, whereas steaming,

microwaving A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce ...

, or stir frying does not cause significant loss. Kale is high in oxalic acid, the levels of which can be reduced by cooking. Kale contains high levels of

polyphenols Polyphenols () are a large family of naturally occurring organic compounds characterized by multiples of phenol units. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some of ...

, such as

ferulic acid Ferulic acid is a hydroxycinnamic acid, an organic compound with the formula (CH3O)HOC6H3CH=CHCO2H. The name is derived from the genus ''Ferula'', referring to the giant fennel ('' Ferula communis''). Classified as a phenolic phytochemical, ferul ...

, with levels varying due to environmental and genetic factors.

Culinary uses

As a snack product

Flavored "kale chips" have been produced as a

potato chip A potato chip (North American English; often just chip) or crisp (British and Irish English) is a thin slice of potato that has been either deep fried, baked, or air fried until crunchy. They are commonly served as a snack, side dish, or ap ...

substitute.

Regional uses

Europe

In the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

, a traditional winter dish called " boerenkoolstamppot" is a mix of curly kale and mashed potatoes, sometimes with fried bacon, and served with rookworst ("smoked sausage"). In Northern Germany, there is a winter tradition known as " Kohlfahrt" ("kale trip"), where a group of people will go on a hike through the woods during the day before gathering at an inn or private residence where kale is served, usually with bacon and

Kohlwurst Kohlwurst, Lungenwurst or Lungwurst is a simple, fresh, strongly smoked sausage (''Rohwurst'') made of lights, pork and fat, which is mostly eaten cooked with kale (cabbage) dishes such as '' Knieperkohl''. It is mainly used in Northeast and Nor ...

("kale sausage"). Kale is considered a Northern German staple and

comfort food Comfort food is food that provides a nostalgic or sentimental value to someone, and may be characterized by its high caloric nature, high carbohydrate level, or simple preparation. The nostalgia may be specific to an individual, or it may app ...

. In Italy, cavolo nero kale is an ingredient of the Tuscan soup

ribollita Ribollita is a Tuscan bread soup, panade, porridge, or potage made with bread and vegetables, often from leftovers. There are many variations but the main ingredients always include leftover bread, cannellini beans, lacinato kale, cabbage, a ...

. A traditional Portuguese soup, ''

caldo verde ''Caldo verde'' (, Portuguese for "green broth") is a popular soup in Portuguese cuisine. The basic traditional ingredients for ''caldo verde'' are finely shredded Portuguese cabbage or ''couve-galega'' (essentially a type of collard green), ...

'', combines pureed potatoes, very finely sliced kale, olive oil and salt. Additional ingredients can include broth and sliced, cooked spicy

sausage A sausage is a type of meat product usually made from ground meat—often pork, beef, or poultry—along with salt, spices and other flavourings. Other ingredients, such as grains or breadcrumbs may be included as fillers or extenders. ...

. In Scotland, kale provided such a base for a traditional diet that the word in some Scots dialects is synonymous with food. To be "off one's kail" is to feel too ill to eat. In Ireland, kale is mixed with mashed potatoes to make the traditional dish ''

colcannon Colcannon () is a traditional Irish dish of mashed potatoes with cabbage or kale. Description Colcannon is most commonly made with only four ingredients: potatoes, butter, milk and cabbage (or kale). Irish historian Patrick Weston Joyce defined ...

''. It is popular on Halloween, when it may be served with sausages.

Asia

In Sri Lanka, it is known as ''kola gova'' or ela gova. It is cultivated for edible use. A dish called 'kale mallung' is served almost everywhere on the island, along with rice.

In literature

The ''Kailyard'' school of Scottish writers, which included

J. M. Barrie Sir James Matthew Barrie, 1st Baronet, (; 9 May 1860 19 June 1937) was a Scottish novelist and playwright, best remembered as the creator of Peter Pan. He was born and educated in Scotland and then moved to London, where he wrote several succ ...

(creator of

Peter Pan Peter Pan is a fictional character created by Scottish novelist and playwright J. M. Barrie. A free-spirited and mischievous young boy who can fly and never grows up, Peter Pan spends his never-ending childhood having adventures on the mythi ...

), consisted of authors who wrote about traditional rural Scottish life (''kailyard'' = 'kale field'). In Cuthbertson's book ''Autumn in Kyle and the charm of Cunninghame'', he states that

Kilmaurs Kilmaurs () is a village in East Ayrshire, Scotland which lies just outside of the largest settlement in East Ayrshire, Kilmarnock. It lies on the Carmel Water, southwest of Glasgow. Population recorded for the village in the 2001 Census recorde ...

East Ayrshire East Ayrshire ( sco, Aest Ayrshire; gd, Siorrachd Àir an Ear) is one of thirty-two council areas of Scotland. It shares borders with Dumfries and Galloway, East Renfrewshire, North Ayrshire, South Ayrshire and South Lanarkshire. The headquar ...

was famous for its kale, which was an important foodstuff. A story is told in which a neighbouring village offered to pay a generous price for some kale seeds, an offer too good to turn down. The locals agreed, but a gentle roasting on a shovel over a coal fire ensured the seeds never germinated.Cuthbertson, David Cuningham (1945). ''Autumn in Kyle and the Charm of Cunninghame''. London: Jenkins. Page 186

Gallery

File:Kale-Bundle.jpg, Curly-leaf kale File:CSA-Red-Russian-Kale.jpg, Red Russian kale File:20170526-AMS-LSC-0326 (34137217614).jpg, Tuscan kale File:Making kale chips in Lockport, Illinois.jpg, Making kale chips in Illinois File:Kogt skinke brunede kartofler grønlangkål.jpg, A traditional

New Years New Year is the time or day currently at which a new calendar year begins and the calendar's year count increments by one. Many cultures celebrate the event in some manner. In the Gregorian calendar, the most widely used calendar system to ...

Danish dish: boiled ham, glazed potatoes and stewed kale File:Vegan Stack at Two Mountains (cropped).jpg, A kale-based dish with other vegetables and sourdough bread, served at a restaurant in Australia

References

External links

Marrow-Stem Kale
– Plants for a Future database
PROTAbase on ''Brassica oleracea'' (leaf cabbage)
{{Authority control Brassica oleracea Leaf vegetables