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.
Primitive forms of spinach are found in Nepal and that is probably where the plant was 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, it was taken to China, possibly by Persians. Muslim Arabs diffused the plant westward up to Islamic Spain. By the eleventh century it was a common plant in the Muslim world.
In India, in Malayalam, it is called Cheera (ചീര), in Tamil, it is called Keerai and in Marathi it is known as Palak .Paala koora 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.”
Spinach is known as a rich source of iron and calcium. According to the United States Department of Agriculture, a 180 gram serving of boiled spinach contains 6.43 mg of iron, whereas one 6 oz. (170 gram) ground hamburger patty contains at most 4.42 mg. Thus spinach does contain a relatively high level of iron, compared to other vegetable and meat sources.
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.
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.
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, In addition to preventing absorption and use, high levels of oxalates remove iron from the body. 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 with out additional oxalic acid. However, foods such as spinach that are high in oxalic acid can increase the risk of kidney stones in some people.
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. The calcium in spinach is the least bioavailable of calcium sources.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.
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.
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
Popeye the Sailor Man has a strong affinity for spinach, becoming physically stronger after consuming it. This is partially due to the iron content being mistakenly reported ten times the actual value, a value that was rechecked during the 1930s, where it was revealed that the original German scientist, Dr. E. von Wolf, had misplaced a decimal point in his calculations.
In truth, spinach actually has about the same iron content as a lot of other vegetables, and even less than others. Cooked broccoli and cauliflower, for example, have almost double the iron content of spinach.
Spinach, along with brussels sprouts and other green vegetables, is often considered in children’s shows to be undesirable.
You can Find some of the recipes containing Spinach here in Ayesha’s Kitchen: