Spinach
Spinach is a leafy green flowering plant native to central and western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common edible vegetable consumed either fresh, or after storage using preservation techniques by canning, freezing, or dehydration. It may be eaten cooked or raw, and the taste differs considerably; the high oxalate content may be reduced by steaming.
It is an annual plant, growing as tall as. Spinach may overwinter in temperate regions. The leaves are alternate, simple, ovate to triangular, and very variable in size: long and broad, with larger leaves at the base of the plant and small leaves higher on the flowering stem. The flowers are inconspicuous, yellow-green, in diameter, and mature into a small, hard, dry, lumpy fruit cluster across containing several seeds.
In 2018, world production of spinach was 26.3 million tonnes, with China alone accounting for 90% of the total.
Etymology
The English word "spinach" dates to the late 14th century from espinache of uncertain origin.Taxonomy
Common spinach, S. oleracea, was long considered to be in the family Chenopodiaceae, but in 2003 that family was merged into the Amaranthaceae in the order Caryophyllales. Within the family Amaranthaceae sensu lato, Spinach belongs to the subfamily Chenopodioideae.Description
Spinach is an annual plant growing as tall as. Spinach may overwinter in temperate regions. The leaves are alternate, simple, ovate to triangular, and very variable in size: long and broad, with larger leaves at the base of the plant and small leaves higher on the flowering stem. The flowers are inconspicuous, yellow-green, in diameter, and mature into a small, hard, dry, lumpy fruit cluster across containing several seeds.Nutrients
Raw spinach is 91% water, 4% carbohydrates, 3% protein, and contains negligible fat. In a serving providing only 23 calories, spinach has a high nutritional value, especially when fresh, frozen, steamed, or quickly boiled. It is a rich source of vitamin A, vitamin C, vitamin K, magnesium, manganese, iron and folate. Spinach is a good source of the B vitamins riboflavin and vitamin B6, vitamin E, calcium, potassium, and dietary fiber. Although spinach is touted as being high in iron and calcium content, and is often served and consumed in its raw form, raw spinach contains high levels of oxalates, which block absorption of calcium and iron in the stomach and small intestine. Spinach cooked in several changes of water has much lower levels of oxalates and is better digested and its nutrients absorbed more completely.Iron
Spinach, along with other green, leafy vegetables, contains an appreciable amount of iron attaining 21% of the Daily Value in a amount of raw spinach. For example, the United States Department of Agriculture states that a serving of cooked spinach contains of iron, whereas a ground hamburger patty contains mg of iron. However, spinach contains iron absorption-inhibiting substances, including high levels of oxalate, which can bind to the iron to form ferrous oxalate and render much of the iron in spinach unusable by the body. In addition to preventing absorption and use, high levels of oxalates remove iron from the body.Calcium
Spinach also has a moderate calcium content which can be affected by oxalates, decreasing its absorption. The calcium in spinach is among the least bioavailable of food calcium sources. By way of comparison, the human body can absorb about half of the calcium present in broccoli, yet only around 5% of the calcium in spinach.Vitamin K
A quantity of 3.5 ounces of spinach contains over four times the recommended daily intake of vitamin K. For this reason, individuals taking the anticoagulant warfarin - which acts by inhibiting vitamin K - are instructed to minimize consumption of spinach to avoid blunting the effect of warfarin.Production, marketing, and storage
In 2018, world production of spinach was 26.3 million tonnes, with China alone accounting for 90% of the total.Fresh spinach is sold loose, bunched, or packaged fresh in bags. Fresh spinach loses much of its nutritional value with storage of more than a few days. Fresh spinach is packaged in air, or in nitrogen gas to extend shelf life. While refrigeration slows this effect to about eight days, fresh spinach loses most of its folate and carotenoid content over this period of time. For longer storage, it is canned, or blanched or cooked and frozen.
Some packaged spinach is exposed to radiation to kill any harmful bacteria. The Food and Drug Administration approves of irradiation of spinach leaves up to 4.0 kilograys, having no or only a minor effect on nutrient content. Spinach may be high in cadmium contamination depending on the soil and location where the spinach is grown.
In popular culture
The comics and cartoon character Popeye the Sailor Man has been portrayed since 1931 as having a strong affinity for spinach, particularly the canned variety. He becomes physically stronger after consuming it.History
Spinach is thought to have originated about 2000 years ago in ancient Persia from which it was introduced to India and ancient China via Nepal in 647 AD as the "Persian vegetable". In AD 827, the Saracens introduced spinach to Sicily. The first written evidence of spinach in the Mediterranean was recorded in three 10th-century works: a medical work by al-Rāzī and in two agricultural treatises, one by Ibn Waḥshīyah and the other by Qusṭus al-Rūmī. Spinach became a popular vegetable in the Arab Mediterranean and arrived in Spain by the latter part of the 12th century, where Ibn al-ʻAwwām called it raʼīs al-buqūl, 'the chieftain of leafy greens'. Spinach was also the subject of a special treatise in the 11th century by Ibn Ḥajjāj.Spinach first appeared in England and France in the 14th century, probably via Spain, and gained common use because it appeared in early spring when fresh local vegetables were not available. Spinach is mentioned in the first known English cookbook, the Forme of Cury, where it is referred to as 'spinnedge' and/or 'spynoches'. During World War I, wine fortified with spinach juice was given to injured French soldiers with the intent to curtail their bleeding.