spinach

Spinach
Spinach in flower
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Caryophyllales
Family:	Amaranthaceae, formerly Chenopodiaceae[1]
Genus:	Spinacia
Species:	S. oleracea
Binomial name
Spinacia oleracea L.

Spinach (Spinacia oleracea) is an edible flowering plant in the family of Amaranthaceae. It is native to central and southwestern Asia. It is an annual plant (rarely biennial), which grows to a height of up to 30 cm. Spinach may survive over winter in temperate regions. The leaves are alternate, simple, ovate to triangular-based, very variable in size from about 2-30 cm long and 1-15 cm broad, with larger leaves at the base of the plant and small leaves higher on the flowering stem. The flowers are inconspicuous, yellow-green, 3-4 mm diameter, maturing into a small hard dry lumpy fruit cluster 5-10 mm across containing several seeds.

History

Primitive forms of spinach are found in Nepal, where the plant was probably first domesticated. Other than the Indian subcontinent, it was unknown in the ancient world. After the early Muslim conquests the plant spread to other areas. In 647 A.D, it was taken to China, possibly by Persians. Muslim Arabs diffused the plant westward up to Islamic Iberia. By the eleventh century it was a common plant in the Muslim world.^[1]

In India, in Kannada, it is called Basale soppu(ಬಸಳೆ ಸೊಪ್ಪು),in Malayalam, it is called Cheera (ചീര), in Tamil, it is called Pasalai Keerai (பசலை கீரை) and in Marathi it is known as Palak (पालक), Paala koora (పాల కూర) in Telugu and is one among commonly consumed green vegetables.

Spinach was the favorite vegetable of Catherine de Medici, a historical figure in the 16th century. When she left her home of Florence, Italy, to marry the king of France, she brought along her own cooks, who could prepare spinach the ways that she especially liked. Since this time, dishes prepared on a bed of spinach are referred to as "a la Florentine." ^[2]

Culinary information

Nutrition

Iron

Spinach is considered to be a rich source of iron. For example, the United States Department of Agriculture states that a 180 g serving of boiled spinach contains 6.43 mg of iron, whereas one 170 g ground hamburger patty contains at most 4.42 mg.^[3]

The bioavailability of iron is dependent on its absorption. This is influenced by a number of factors. Iron enters the body in two forms: nonheme iron and heme iron. All of the iron in grains and vegetables, and about three fifths of the iron in animal food sources (meats), is nonheme iron. The much smaller remaining portion from meats is heme iron.^[4] Thus, the iron in spinach is poorly absorbed by the body unless eaten with vitamin C. The type of iron found in spinach is non-blood (non-heme), a plant iron, which the body does not absorb as efficiently as blood (heme) iron, found in meat.^[5]

The larger portion of dietary iron (nonheme) is absorbed slowly in its many food sources, including spinach. This absorption may vary widely depending on the presence of binders such as fiber or enhancers, such as vitamin C. Therefore, the body's absorption of non-heme iron can be improved by consuming foods that are rich in vitamin C. However, spinach contains iron absorption inhibiting substances, including high levels of oxalate which can bind to the iron to form ferrous oxalate, which renders much of the iron in spinach unusable by the body ^[6]. In addition to preventing absorption and use, high levels of oxalates remove iron from the body.^[7] But some studies have found that the addition of oxalic acid to the diet may improve iron absorption in rats over a diet with spinach without additional oxalic acid.^[8] However, foods such as spinach that are high in oxalic acid can increase the risk of kidney stones in some people.

Calcium

Spinach also has a high calcium content. However, the oxalate content in spinach also binds with calcium decreasing its absorption. Calcium and zinc also limit iron absorption.^[9] The calcium in spinach is the least bioavailable of calcium sources.^[10] By way of comparison, the body can absorb about half of the calcium present in broccoli, yet only around 5% of the calcium in spinach. Oxalate is one of a number of factors that can contribute to gout and kidney stones. Equally or more notable factors contributing to calcium stones are: genetic tendency, high intake of animal protein, excess calcium intake, excess vitamin D, prolonged immobility, hyperparathyroidism, renal tubular acidosis, and excess dietary fiber.^[4]

Pureed Spinach & Homemade Cheese with Spiced Flat Bread Makki di roti from Punjab, India.

Other

Spinach has a high nutritional value and is extremely rich in antioxidants, especially when fresh, steamed, or quickly boiled. It is a rich source of vitamin A (and lutein), vitamin C, vitamin E, vitamin K, magnesium, manganese, folate, iron, vitamin B2, calcium, potassium, vitamin B6, folic acid, copper, protein, phosphorus, zinc, niacin, selenium and omega-3 fatty acids. Recently, opioid peptides called rubiscolins have also been found in spinach. It is a source of folic acid (Vitamin B₉), and this vitamin was first purified from spinach. To benefit from the folate in spinach, it is better to steam it than to boil it. Boiling spinach for four minutes can halve the level of folate.^{[citation needed]}.

Types of spinach

A distinction can be made between older varieties of spinach and more modern varieties. Older varieties tend to bolt too early in warm conditions. Newer varieties tend to grow more rapidly but have less of an inclination to run up to seed. The older varieties have narrower leaves and tend to have a stronger and more bitter taste. Most newer varieties have broader leaves and round seeds.

There are three basic types of spinach:

• Savoy has dark green, crinkly and curly leaves. It is the type sold in fresh bunches in most supermarkets. One heirloom variety of savoy is Bloomsdale, which is somewhat resistant to bolting.

• Flat/smooth leaf spinach has broad smooth leaves that are easier to clean than savoy. This type is often grown for canned and frozen spinach, as well as soups, baby foods, and processed foods.

• Semi-savoy is a hybrid variety with slightly crinkled leaves. It has the same texture as savoy, but it is not as difficult to clean. It is grown for both fresh market and processing. Five Star is a widely grown variety and has good resistance to running up to seed.

Production, marketing and storage

Spinach output in 2005

Spinach is sold loose, bunched, in prepackaged bags, canned, or frozen. Fresh spinach loses much of its nutritional value with storage of more than a few days.^[11] While refrigeration slows this effect to about eight days, spinach will lose most of its folate and carotenoid content, so for longer storage it is frozen, cooked and frozen, or canned. Storage in the freezer can be for up to eight months.

The Environmental Working Group reports that spinach is one of the dozen most heavily pesticide-contaminated produce products.[2] The most common pesticides found on spinach are Permethrin, Dimethoate, and DDT.^{[citation needed]}

Spinach in popular culture

The cartoon character Popeye the Sailor Man is portrayed as having a strong affinity for spinach, becoming physically stronger after consuming it. The BBC has reported that this portrayal is partially due to the iron content having been mistakenly being reported as ten times the actual value; a value that was rechecked during the 1930s, whereby it was revealed that the original German scientist, Dr. E. von Wolf, had misplaced a decimal point in his calculations.^[12]

Spinach, along with Brussels sprouts and other green vegetables, is often portrayed in children's shows to be undesirable.^[12]

United States

Driven by fresh-market use, the consumption of spinach (Spinacia oleracea) has been on the rise in the United States. Per capita use of fresh-market spinach averaged 1 kg during 2004-06, the highest since the mid-1940s. The fresh market now accounts for about three-fourths of all U.S. spinach consumed. Much of the growth over the past decade has been due to sales of triple-washed cello-packed spinach and, more recently, baby spinach. These packaged products have been one of the fastest-growing segments of the packaged salad industry.

Tostitos brand spinach dip

The United States is the world’s second-largest producer of spinach, with 3 percent of world output, following China (PRC), which accounts for 85 percent of output. A cool-season crop that grows quickly and can withstand hard frosts, spinach is a native of Indian subcontinent and has been cultivated in China since at least the 7th century. Spinach use was recorded in Europe as early as the mid-13th century, with seed accompanying colonists to the New World.

California (73 percent of 2004-06 U.S. output), Arizona (12 percent), and New Jersey (3 percent) are the top producing states, with 12 other states reporting production of at least 100 acres (2002 census). Over the 2004-06 period, U.S. growers produced an average of 867 million pounds of spinach for all uses, with about three-fourths sold into the fresh-market (includes fresh-cut/processed). According to the 2002 Census of Agriculture, spinach was grown on 1,109 U.S. farms - down 17% from 1997, but about the same number as in 1987.

The farm value of U.S. spinach crops (fresh and processed) averaged $175 million during 2004-06, with fresh market spinach accounting for 94 percent. The value of fresh market spinach has more than doubled over the past decade as stronger demand has boosted production, while inflation-adjusted prices largely remained constant. California accounts for about three-fourths of the value of both the fresh and processing spinach crops.

Like other cool-season leafy crops, most (about 96 percent) of the fresh spinach consumed in the United States is produced domestically. Although rising, imports (largely from Mexico) totaled about 23 million pounds in 2004-06, compared with 3 million pounds in 1994-06. During the last 10 years, exports (largely to Canada) have jumped 70 percent to 47 million pounds (2004-06), with much of the growth occurring earlier this decade.^[13]

Per capita spinach consumption is greatest in the Northeast and Western US. About 80 percent of fresh-market spinach is purchased at retail and consumed at home, while 91 percent of processed spinach is consumed at home. Per capita spinach use is strongest among Asians, highest among women 40 and older, and weakest among teenage girls.^[14]

2006 United States E. coli outbreak

See Wikinews article: E. coli outbreak kills 1 sickens nearly 100

In September 2006, there was an outbreak of disease caused by the E. coli strain O157:H7 in 21 U.S. states. Over a hundred cases were reported, including five deaths. The E. coli was linked to bags of fresh spinach, after which the FDA issued a warning not to eat uncooked fresh spinach or products containing it. The U.S. Food and Drug Administration issued a press release updating the available information. According to the FDA release as on 2006-10-4, 192 cases of E. coli O157:H7 infection have been reported to the Centers for Disease Control and Prevention (CDC) including 30 cases of Hemolytic Uremic Syndrome; there was one death and 98 hospitalizations. The infection affected 26 states. By early 2007, there were 206 illnesses and three deaths attributed to E. coli-tainted spinach.

Based on epidemiological and laboratory evidence, the FDA determined that the implicated spinach originated from an organic spinach field grown by Mission Organics and processed by Natural Selection Foods LLC of San Juan Bautista, California. The FDA speculated that the spinach had been tainted by irrigation water contaminated with wild pig feces because feral pigs were seen in the vicinity of the implicated ranch.

2007 United States salmonella outbreak

On August 30, 2007, 8,000 cartons of spinach (from Metz Fresh, a King City-based grower and shipper, Salinas Valley, California) were recalled after salmonella was discovered upon routine test. Consumer advocates and some lawmakers complained it exposed big gaps in food safety, even if 90% of suspect vegetable didn’t reach the shelves.^[15]

Other species called spinach

The name spinach has been applied to a number of leaf vegetables, both related and unrelated to spinach:

Related species

• Chard (Beta vulgaris, Amaranthaceae), also known as spinach beet, silverbeet or perpetual spinach.
• Orache (Atriplex species, Amaranthaceae), also called "French spinach" or "mountain spinach".
• Good King Henry (Chenopodium bonus-henricus, Amaranthaceae) and other Chenopodium species, also called "Lincolnshire spinach".

In Indonesia, the word bayam is applied both to certain species of amaranth commonly eaten as a leafy vegetable, and to spinach, which is rarely seen, only in certain supermarkets but well known from Popeye cartoons.

Unrelated species

• New Zealand spinach (Tetragonia, Aizoaceae).
• Water spinach (Convolvulaceae).
• Malabar spinach (Basellaceae).
• The greens of various nightshade, legume and cucurbit species are also known as spinach, wild spinach, African spinach, "Thermadorian spinach" or morogo (in Southern Africa).
• Sorrel, also known as Spinach Dock.

References

Further reading

• D. Maue, S. Walia, S. Shore, M. Parkash, S. K. Walia, S. K. Walia (2005). "Prevalence of Multiple Antibiotic Resistant Bacteria in Ready-to-Eat Bagged Salads". American Society for Microbiology meeting. June 5-9. pp. Atlanta.  Abstract
• Overview of Spinach from Innvista
• Rogers, Jo. What Food is That?: and how healthy is it?. The Rocks, Sydney, NSW: Lansdowne Publishing Pty Ltd, 1990. ISBN 1-86302-823-4.
• Cardwell, Glenn. Spinach is a Good Source of What?. The Skeptic. Volume 25, No 2, Winter 2005. Pp 31–33. ISSN 0726-9897
• Blazey, Clive. The Australian Vegetable Garden: What's new is old. Sydney, NSW: New Holland Publishers, 1999. ISBN 1-86436-538-2
• Stanton, Rosemary. Complete Book of Food and Nutrition. Australia, Simon & Schuster, Revised Edition, 1995. ISBN 0-7318-0538-0

External links

Wikibooks Cookbook has a recipe/module on Spinach

Wikimedia Commons has media related to: Spinacia oleracea

• FAO spinach data sheet
• Fresh-Market Spinach: Background Information and Statistics USDA 2007
• Factors Affecting Spinach Consumption in the United States USDA 2004
• US import/export data
• Powell, D. and Chapman "Fresh and Risky" Food Safety Network, September 15, 2006
•  "spinach". Encyclopædia Britannica (11th ed.). 1911.