Kale

Kale

Curly kale
Details
Species Brassica oleracea
Cultivar group Acephala Group
Origin Unknown, before the Middle Ages
Cultivar group members Many, and some are known by other names.

Kale or borecole is a form of cabbage (Brassica oleracea Acephala Group), green or purple, in which the central leaves do not form a head. It is considered to be closer to wild cabbage than most domesticated forms. The species Brassica oleracea contains a wide array of vegetables including broccoli, cauliflower, collard greens, and brussels sprouts. The cultivar group Acephala also includes spring greens and collard greens, which are extremely similar genetically.

Contents

Name

The name borecole most likely originates from the Dutch boerenkool (farmer's cabbage).

Nutritional value

Kale, cooked, boiled, drained, without salt
Nutritional value per 100 g (3.5 oz)
Energy 117 kJ (28 kcal)
Carbohydrates 5.63
- Sugars 1.25
- Dietary fiber 2.0
Fat 0.40
Protein 1.90
Water 91.20
Alcohol 0
Caffeine 0
Vitamin A 13621 IU
- beta-carotene 8173 μg (76%)
- lutein and zeaxanthin 18246 μg
Thiamine (vit. B1) 0.053 mg (5%)
Riboflavin (vit. B2) 0.070 mg (6%)
Niacin (vit. B3) 0.500 mg (3%)
Pantothenic acid (B5) 0.049 mg (1%)
Vitamin B6 0.138 mg (11%)
Folate (vit. B9) 13 μg (3%)
Vitamin B12 0 μg (0%)
Choline 0.4 mg (0%)
Vitamin C 41.0 mg (49%)
Vitamin D 0 μg (0%)
Vitamin D 0 IU (0%)
Vitamin E 0.85 mg (6%)
Vitamin K 817.0 μg (778%)
Calcium 72 mg (7%)
Iron 0.90 mg (7%)
Magnesium 18 mg (5%)
Manganese 0.416 mg (20%)
Phosphorus 28 mg (4%)
Potassium 228 mg (5%)
Sodium 23 mg (2%)
Zinc 0.24 mg (3%)
Percentages are relative to US recommendations for adults.
Source: USDA Nutrient Database

Kale is very high in beta carotene, vitamin K, vitamin C, lutein, zeaxanthin, and reasonably rich in calcium. Kale, as with broccoli and other brassicas, contains sulforaphane (particularly when chopped or minced), a chemical with potent anti-cancer properties.[1] Boiling decreases the level of sulforaphane; however, steaming, microwaving, or stir frying do not result in significant loss.[2] Along with other brassica vegetables, kale is also a source of indole-3-carbinol, a chemical which boosts DNA repair in cells and appears to block the growth of cancer cells.[3][4] Kale is also a good source of carotenoids.[5]

Origins

Until the end of the Middle Ages, kale was one of the most common green vegetables in all of Europe. Curly leafed varieties of cabbage already existed along with flat leafed varieties in Greece in the fourth century BC. These forms, which were referred to by the Romans as Sabellian kale, are considered to be the ancestors of modern kales. Today one may differentiate between varieties according to the low, intermediate, or high length of the stem, with varying leaf types. The leaf colours range from light green through green, dark green and violet-green to violet-brown. Russian kale was introduced into Canada (and then into the U.S.) by Russian traders in the 19th century.

During World War II, the cultivation of kale in the U.K. was encouraged by the Dig for Victory campaign. The vegetable was easy to grow and provided important nutrients to supplement those missing from a normal diet because of rationing.[6]

Kai-lan, a separate cultivar of Brassica oleracea much used in Chinese cuisine, is somewhat similar to kale in appearance and is occasionally called "kale" in English.

Cultivars

Kales can be classified by leaf type:

Because Kale can grow well into winter, one variety of Rape Kale is called 'Hungry Gap', named after the period in winter in traditional agriculture when little could be harvested.

Culinary uses

Kale freezes well and actually tastes sweeter and more flavourful after being exposed to a frost.

Tender kale greens can provide an intense addition to salads, particularly when combined with other such strongly flavoured ingredients as dry-roasted peanuts, tamari-roasted almonds, red pepper flakes, or an Asian-style dressing.

In the Netherlands it is very frequently used in a winter dish (a stamppot), as a traditional Dutch dish called boerenkool.

In Ireland kale is mixed with mashed potatoes to make the traditional dish colcannon. It is popular on Halloween when it is sometimes served with sausages. Small coins are sometimes hidden inside as prizes.

Kale is a very popular vegetable in China, Taiwan, and Vietnam, where it is commonly stir-fried with beef.

A traditional Portuguese soup, caldo verde, combines pureed potatoes, diced kale, olive oil, broth, and, generally, sliced cooked spicy sausage. Under the name of couve, kale is also popular in Brazil, in caldo verde, or as a vegetable dish, often cooked with carne seca (shredded dried beef). When chopped and stir-fried, couve accompanies Brazil's national dish, feijoada.

In East Africa, it is an essential ingredient in making a stew for ugali, which is almost always eaten with kale. Kale is also eaten throughout southeastern Africa, where it is typically boiled with coconut milk and ground peanuts and is served with rice or boiled cornmeal.

A whole culture around kale has developed in north-western Germany around the towns of Bremen, Oldenburg and Hannover. There, most social clubs of any kind will have a Grünkohlfahrt ("kale tour") sometime between October and February, visiting a country inn to consume large quantities of boiled kale, Kassler, Mettwurst and schnapps. These tours are often combined with a game of Boßeln. Most communities in the area have a yearly kale festival which includes naming a "kale king" (or queen).

Curly kale is used in Denmark and Holland, Sweden, to make (grøn-)langkål, an obligatory dish on the julbord in the region, and is commonly served together with the Christmas ham (Sweden, Holland). The kale is used to make a stew of minced boiled kale, stock, cream, pepper and salt that is simmered together slowly for a few hours. In Scotland, kale provided such a base for a traditional diet that the word in dialect Scots is synonymous with food. To be "off one's kail" is to feel too ill to eat.

In Montenegro collards, locally known as rashtan is a favorite vegetable. It is particularly popular in winter, cooked with smoked mutton (kastradina) and potatoes.

In the Southern United States, Kale is often served braised, either alone or mixed with other greens, such as Collard, Mustard, or Turnip.

Kale is a very good source of iron, calcium, vitamin C, vitamin K and Carotenoids (which provide vitamin A). In Japan, kale juice (known as aojiru) is a popular dietary supplement.

Decorative uses

Many varieties of kale are referred to as "flowering kales" and are grown mainly for their ornamental leaves, which are brilliant white, red, pink, lavender, blue or violet in the interior or the rosette. Most plants sold as "ornamental cabbage" are in fact kales. Ornamental kale is as edible as any other variety.[7]

When uncooked, standard Kale is a popular garnish.

Literature

The Kailyard school of Scottish writers, which included J. M. Barrie (creator of Peter Pan), consisted of authors who wrote about traditional rural Scottish life (kailyard = kale field). In Cuthbertson's quaint book 'Autumn in Kyle and the charm of Cunninghame' he recalls that Kilmaurs in East Ayrshire, was famous for its kale which was an important foodstuff. A story is told of how a neighbouring village offered to pay a generous price for some kale seeds, an offer too good to turn down. The cunning locals agreed; however a gentle roasting on a shovel over a coal fire ensured that the seeds never germinated.[8]

See also

References

  1. ^ Yuesheng Zhang & Eileen C. Callaway (May 2002). "High cellular accumulation of sulphoraphane, a dietary anticarcinogen, is followed by rapid transporter-mediated export as a glutathione conjugate". The Biochemical journal 364 (Pt 1): 301–307. PMC 1222573. PMID 11988104. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1222573. 
  2. ^ Warwick Medical School, University of Warwick (2007-05-15). "Research Says Boiling Broccoli Ruins Its Anti Cancer Properties". http://www2.warwick.ac.uk/newsandevents/pressreleases/research_says_boiling/. 
  3. ^ "Broccoli chemical's cancer check". BBC News. 7 February 2006. http://news.bbc.co.uk/2/hi/health/4688854.stm. Retrieved 5 September 2010. 
  4. ^ "How Dietary Supplement May Block Cancer Cells". Science Daily. 30 June 2010. http://www.sciencedaily.com/releases/2010/06/100629131316.htm. Retrieved 5 September 2010. 
  5. ^ "Breeding Better Broccoli: Research Points To Pumped Up Lutein Levels In Broccoli". Science Daily. 8 November 2009. http://www.sciencedaily.com/releases/2009/11/091104132824.htm. Retrieved 5 September 2010. 
  6. ^ "World War Two vegetable comes back as 'superfood'". Daily Mail (London). 3 October 2007. http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=485506&in_page_id=1770. 
  7. ^ Detailed information on Flowering Cabbage, Ornamental Kale, Collard, Cole Brassica oleracea var. acephala
  8. ^ Cuthbertson, David Cuningham (1945). 'Autumn in Kyle and the Charm of Cunninghame'. London : Jenkins. Page 186

External links