Kale
Kale, also called leaf cabbage, belongs to a group of cabbage cultivars primarily grown for their edible leaves, but it is also used as an ornamental plant. Its multiple different cultivars vary quite a bit in appearance; the leaves can be bumpy, curly, or flat, and the color ranges from purple to green.
Description
Kale plants have green or purple leaves, and the central leaves do not form a head, as with headed cabbage. The stems can be white or red, and can be tough even when cooked.Etymology
The name kale originates from Northern Middle English cale for various cabbages. The ultimate origin is Latin caulis 'cabbage'.Cultivation
Derived from wild mustard, kale is considered to be closer to wild cabbage than most domesticated forms of B. oleracea.Kale is usually a biennial 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. Kale can become sweeter after a heavy frost.
History
Kale originated in the eastern Mediterranean and Anatolia, 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 in the 4th century BC. These forms, which were referred to by the Romans 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 botanist David Fairchild is credited with introducing kale to Americans, having brought it back from Croatia, 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.
Cultivars
Kale varieties can be differentiated according to the low, intermediate, or high length of the stem, and the variety of leaf types. Leaf colours range from light green to green, dark green, violet-green, and violet-brown.Classification by leaf type:
- Curly-leaf
- Bumpy-leaf
- Sparkly-leaf
- Plain-leaf
- Leaf and spear, or feathery-type leaf
- Ornamental
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. In 2012, Pizza Hut purchased approximately 14,000 lbs of kale for use in salad bar decoration. Kale leaves are increasingly used as an ingredient for vegetable bouquets and wedding bouquets.Uses
Nutrition
Raw kale is 84% water, 9% carbohydrates, 4% protein, and 1% fat. In a serving, raw kale provides of food energy and 3.7 times the Daily Value of vitamin K. It is a rich source of vitamin A, vitamin C, folate, and manganese. Kale is a good source of riboflavin, pantothenic acid, vitamin B6, vitamin E, and several dietary minerals, including calcium, magnesium, and potassium. Boiling raw kale diminishes most of these nutrients, while values for vitamins A, C, and K and manganese remain substantial.Phytochemicals
Kale is a source of the carotenoids, lutein and zeaxanthin. As with broccoli and other cruciferous vegetables, kale contains glucosinolate compounds, such as glucoraphanin, which contributes to the formation of sulforaphane, a compound under preliminary research for its potential to affect human health beneficially.Boiling kale decreases the level of glucosinate compounds, whereas steaming, microwaving, 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, such as ferulic acid, with levels varying due to environmental and genetic factors.
Culinary
Snack product
Kale chips have been produced as a potato chip substitute.Regional uses
Europe
In the Netherlands, a traditional winter dish called "boerenkoolstamppot" is a mix of curly kale and mashed potatoes, sometimes with fried bacon, and served with rookworst.In Northern Germany, there is a winter tradition known as "Kohlfahrt", 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. Kale is considered a Northern German staple and comfort food.
In Italy, cavolo nero kale is an ingredient of the Tuscan soup ribollita.
A traditional Portuguese soup, caldo verde, combines pureed potatoes, very finely sliced kale, olive oil and salt. Additional ingredients can include broth and sliced, cooked spicy sausage.
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. It is popular on Halloween, when it may be served with sausages.
In the United Kingdom, the cultivation of kale was encouraged during World War II via the Dig for Victory campaign.