Nutrition Raw kale is 84% water, 9%
carbohydrates, 4%
protein, and 1%
fat (table). In a serving, raw kale provides of
food energy and 3.7 times the
Daily Value (DV) of
vitamin K. It is a rich source (20% or more of the DV) of
vitamin A,
vitamin C,
folate, and
manganese (see table "Kale, raw"). Kale is a good source (10–19% DV) of
riboflavin,
pantothenic acid,
vitamin B6,
vitamin E, and several
dietary minerals, including
calcium,
magnesium, and
potassium (table). Boiling raw kale diminishes most of these nutrients, while values for vitamins A, C, and K and manganese remain substantial (table for cooked kale).
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 health effects. 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 ("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 ("kale sausage"). 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 (and other vegetables) was encouraged during
World War II via the
Dig for Victory campaign.
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.
United States For most of the 20th century, kale was primarily used in the U.S. for decorative purposes; it became more commonly consumed starting in the 1990s, mainly due to its nutritional value. == In culture ==