Thursday 18 April 2013

WATERCRESS


Watercress

From Wikipedia, the free encyclopedia
Watercress
Nasturtium officinale
Scientific classification
Kingdom:Plantae
(unranked):Angiosperms
(unranked):Eudicots
(unranked):Rosids
Order:Brassicales
Family:Brassicaceae
Genus:Nasturtium
Species:N. officinale
Binomial name
Nasturtium officinale
W.T. Aiton
Synonyms
Nasturtium nasturtium-aquaticum (L.)H. Karst.
Rorippa nasturtium-aquaticum (L.) Hayek
Sisymbrium nasturtium-aquaticum L.
Watercress (Nasturtium officinale), is a fast-growing, aquatic or semi-aquatic, perennial plant native to Europe and Asia, and one of the oldest knownleaf vegetables consumed by humans. It is a member of the family Brassicaceae, botanically related to garden cressmustard and radish — all noteworthy for a peppery, tangy flavour.
The hollow stems of watercress are floating, and the leaves are pinnately compound. Small, white and green flowers are produced in clusters.

[edit]
Nasturtium nasturtium-aquaticum
 (nomenclaturally invalid) and Sisymbrium nasturtium-aquaticum L. are synonyms of N. officinale. Watercress is also listed in some sources as belonging to the genus Rorippa, although molecular evidence shows the aquatic species with hollow stems are more closely related to Cardamine than Rorippa.[1] Despite the Latin name, watercress is not closely related to the flowers popularly known as nasturtiums (Tropaeolum majus).

[edit]Cultivation

Watercress beds in Warnford,Hampshire.
Cultivation of watercress is practical on both a large-scale and a garden-scale. Being semi-aquatic, watercress is well-suited to hydroponic cultivation, thriving best in water that is slightly alkaline. It is frequently produced around the headwaters of chalk streams. In many local markets, the demand for hydroponically grown watercress exceeds supply, partly because cress leaves are unsuitable for distribution in dried form, and can only be stored fresh for a short period.
Watercress can be sold in supermarkets inside sealed plastic bags, containing a little moisture and lightly pressurised to prevent crushing of contents. This has allowed national availability with a once-purchased storage life of one to two days in chilled/refrigerated storage.
Also sold as sprouts, the edible shoots are harvested days after germination. If unharvested, watercress can grow to a height of 50–120 centimetres (1.6–3.9 ft). Like many plants in this family, the foliage of watercress becomes bitter when the plants begin producing flowers.

[edit]Distribution

Watercress has been grown in many locations around the world.
In the United Kingdom, watercress was first commercially cultivated in 1808 by the horticulturist William Bradbery, along the River Ebbsfleet in Kent. Watercress is now grown in a number of counties of the United Kingdom, most notably HertfordshireHampshireWiltshire and Dorset. The town ofAlresford, near Winchester, holds a Watercress Festival that brings in more than 15,000 visitors every year, and a preserved steam railway line has been named after the local crop. In recent years,[when?] watercress has become more widely available in the UK, at least in the southeast; it is stocked pre-packed in some supermarkets, as well as fresh by the bunch at farmers' markets and greengrocers.
In the United States in the 1940s, Huntsville, Alabama was locally known as the "watercress capital of the world".[2] Today, Oviedo, Florida in the United States is known by that title,[3] while Alresford in England is considered to be that nation's watercress capital.[4]

[edit]Health benefits

Watercress, raw
Nutritional value per 100 g (3.5 oz)
Energy46 kJ (11 kcal)
Carbohydrates1.29 g
Sugars0.2 g
Dietary fiber0.5 g
Fat0.1 g
Protein2.3 g
Vitamin A equiv.160 μg (20%)
beta-carotene1914 μg (18%)
lutein and zeaxanthin5767 μg
Thiamine (vit. B1)0.09 mg (8%)
Riboflavin (vit. B2)0.12 mg (10%)
Pantothenic acid (B5)0.31 mg (6%)
Vitamin B60.129 mg (10%)
Folate (vit. B9)9 μg (2%)
Vitamin C43 mg (52%)
Vitamin E1 mg (7%)
Vitamin K250 μg (238%)
Calcium120 mg (12%)
Iron0.2 mg (2%)
Magnesium21 mg (6%)
Manganese0.244 mg (12%)
Phosphorus60 mg (9%)
Potassium330 mg (7%)
Sodium41 mg (3%)
Link to USDA Database entry
Percentages are relative to
US recommendations for adults.
Source: USDA Nutrient Database
Watercress contains significant amounts of ironcalciumiodine, and folic acid, in addition to vitamins A and C.[5] Because it is relatively rich in Vitamin C, watercress was suggested (among other plants) by English military surgeon John Woodall (1570–1643) as a remedy for scurvy. In some regions, watercress is regarded as a weed, in other regions as an aquatic vegetable or herb. Watercress crops grown in the presence of manure can be a haven for parasites such as the liver fluke Fasciola hepatica.[6]
Many benefits from eating watercress are claimed, such as that it acts as a stimulant, a source of phytochemicals and antioxidants, a diuretic, anexpectorant, and a digestive aid.[7] It also appears to have antiangiogenic cancer-suppressing properties; it is widely believed to help defend againstlung cancer.[8][9][10][11] A 2010 study conducted by the University of Southampton found that consumption of watercress may also inhibit the growth of breast cancer.[12] The content of phenethyl isothiocyanate (PEITC) in watercress inhibits HIF, which can inhibit angiogenesis.
Watercress is mentioned in the Talmud as being able to stop bleeding, when mixed with vinegar.[13]

[edit]Side effects

Watercress is a known inhibitor of the cytochrome P450 CYP2E1, which may result in altered drug metabolism for individuals on certain medications such as chlorzoxazone.[14]

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