Corn. White or yellow, Jersey corn, fresh off the cob is terrific, boiled in water or steamed and if fresh, doesn’t even need butter or spices.
The domestication of maize is of particular interest to researchers — archaeologists, geneticists,ethnobotanists, geographers, etc. The process is thought by some to have started 7,500 to 12,000 years ago. Research from the 1950s to 1970s originally focused on the hypothesis that maize domestication occurred in the highlands between Oaxaca and Jalisco, because the oldest archaeological remains of maize known at the time were found there. Genetic studies led by John Doebley identified Zea mays ssp. parviglumis, native to the Balsas River valley and also known as Balsas teosinte, as being the crop wild relative teosinte genetically most similar to modern maize.[19]However, archaeobotanical studies published in 2009 now point to the lowlands of the Balsas River valley, where stone milling tools with maize residue have been found in a 8,700-years old layer of deposits.[20][21][22] Some of the earliest pollen remains from Latin America have been found in lake sediments from tropics of southern Mexico and upper Central America, up to Laguna Martinez and have been radiocarbon dated to around 4,700 years ago.[citation needed] Archaeological remains of early maize ears, found at Guila Naquitz Cave in the Oaxaca Valley, date back roughly 6,250 years; the oldest ears from caves near Tehuacan, Puebla, date ca. 2750 BC. Little change occurred in ear form until ca. 1100 BC when great changes appeared in ears from Mexican caves: maize diversity rapidly increased and archaeological teosinte was first deposited.
Maize is a major source of starch.Cornstarch (maize flour) is a major ingredient in home cooking and in many industrialized food products. Maize is also a major source of cooking oil (corn oil) and of maize gluten. Maize starch can behydrolyzed and enzymatically treated to produce syrups, particularly high fructosecorn syrup, a sweetener; and also fermented and distilled to produce grain alcohol. Grain alcohol from maize is traditionally the source
Some forms of the plant are occasionally grown for ornamental use in the garden. For this purpose, variegated and colored leaf forms as well as those with colorful ears are used. Size-superlative types, having reached 34 ft (10 m) tall, cobs 2 ft (61 cm) long, or 1 in (2.5 cm) kernels, have been popular for at least a century.[37][38] Corncobs can be hollowed out and treated to make inexpensive smoking pipes, first manufactured in the United States in 1869.
Maize
From Wikipedia, the free encyclopedia
This article is about the cereal grain, also known as corn in some countries. For other uses, seeMaize (disambiguation).
"Corn" redirects here. For other uses, see Corn (disambiguation).
| Maize | |
|---|---|
| Illustration depicting both male and female flowers of maize | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Commelinids |
| Order: | Poales |
| Family: | Poaceae |
| Subfamily: | Panicoideae |
| Tribe: | Andropogoneae |
| Genus: | Zea |
| Species: | Z. mays |
| Binomial name | |
| Zea mays L. | |
Maize (Zea mays L. ssp. mays, pronounced /ˈmeɪz/; from Spanish: maíz after Taíno mahiz,) known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples inMesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable or starch. The Olmec andMayans cultivated it in numerous varieties throughout central and southern Mexico, cooked, ground or processed through nixtamalization. Between 1700 and 1250 BCE, the crop spread through much of theAmericas. The region developed a trade network based on surplus and varieties of maize crops. After European contact with the Americas in the late 15th and early 16th centuries, explorers and traders carried maize back to Europe and introduced it to other countries. Maize spread to the rest of the world due to its ability to grow in diverse climates. Sugar-rich varieties called sweet cornare usually grown for human consumption, while field corn varieties are used for animal feed and as chemical feedstocks.
Maize is the most widely grown crop in the Americas with 332 million metric tons grown annually in the United States. Approximately 40% of the crop - 130 million tons - is used for corn ethanol.[1] Transgenic maize(Genetically Modified Corn) made up 85% of the maize planted in the United States in 2009.[2] While some maize varieties grow to 12 metres (39 ft) tall,[3] most commercially grown maize has been bred for a standardized height of 2.5 metres (8.2 ft). Sweet corn is usually shorter than field corn varieties.
The domestication of maize is of particular interest to researchers — archaeologists, geneticists,ethnobotanists, geographers, etc. The process is thought by some to have started 7,500 to 12,000 years ago. Research from the 1950s to 1970s originally focused on the hypothesis that maize domestication occurred in the highlands between Oaxaca and Jalisco, because the oldest archaeological remains of maize known at the time were found there. Genetic studies led by John Doebley identified Zea mays ssp. parviglumis, native to the Balsas River valley and also known as Balsas teosinte, as being the crop wild relative teosinte genetically most similar to modern maize.[19]However, archaeobotanical studies published in 2009 now point to the lowlands of the Balsas River valley, where stone milling tools with maize residue have been found in a 8,700-years old layer of deposits.[20][21][22] Some of the earliest pollen remains from Latin America have been found in lake sediments from tropics of southern Mexico and upper Central America, up to Laguna Martinez and have been radiocarbon dated to around 4,700 years ago.[citation needed] Archaeological remains of early maize ears, found at Guila Naquitz Cave in the Oaxaca Valley, date back roughly 6,250 years; the oldest ears from caves near Tehuacan, Puebla, date ca. 2750 BC. Little change occurred in ear form until ca. 1100 BC when great changes appeared in ears from Mexican caves: maize diversity rapidly increased and archaeological teosinte was first deposited.
Perhaps as early as 1500 BC, maize began to spread widely and rapidly. As it was introduced to new cultures, new uses were developed and new varieties selected to better serve in those preparations. Maize was the staple food, or a major staple (along with squash, Andean region potato, quinoa, beans, and amaranth), of mostpre-Columbian North American, Mesoamerican, South American, and Caribbean cultures. The Mesoamerican civilization was strengthened upon the field crop of maize; through harvesting it, its religious and spiritual importance and how it impacted their diet. Maize formed the Mesoamerican people's identity. During the 1st millennium AD, maize cultivation spread from Mexico into the U.S. Southwest and during the following millennium into the U.S. Northeast and southeastern Canada, transforming the landscape as Native Americans cleared large forest and grassland areas for the new crop.[citation needed]
It is unknown what precipitated its domestication, because the edible portion of the wild variety is too small and hard to obtain to be eaten directly, as each kernel is enclosed in a very hard bivalve shell. However, George Beadle demonstrated that the kernels of teosinte are readily "popped" for human consumption, like modern popcorn. Some have argued that it would have taken too many generations of selective breeding to produce large, compressed ears for efficient cultivation. However, studies of the hybrids readily made by intercrossing teosinte and modern maize suggest this objection is not well founded.
In 2005, research by the USDA Forest Service indicated the rise in maize cultivation 500 to 1,000 years ago in what is now the southeastern United States contributed to the decline of freshwater mussels, which are very sensitive to environmental changes.[23]
Methods
Because it is cold-intolerant, in the temperate zones maize must be planted in the spring. Its root system is generally shallow, so the plant is dependent on soil moisture. As a C4 plant (a plant that uses C4 carbon fixation), maize is a considerably more water-efficient crop than C3 plants (plants that use C3 carbon fixation) like the small grains, alfalfa and soybeans. Maize is most sensitive to drought at the time of silk emergence, when the flowers are ready for pollination. In the United States, a good harvest was traditionally predicted if the maize was "knee-high by the Fourth of July", although modern hybrids generally exceed this growth rate. Maize used for silage is harvested while the plant is green and the fruit immature. Sweet corn is harvested in the "milk stage", after pollination but before starch has formed, between late summer and early to mid-autumn. Field maize is left in the field very late in the autumn to thoroughly dry the grain, and may, in fact, sometimes not be harvested until winter or even early spring. The importance of sufficient soil moisture is shown in many parts of Africa, where periodicdrought regularly causes famine by causing maize crop failure.
Maize was planted by the Native Americans in hills, in a complex system known to some as the Three Sisters. Maize provided support for beans, and the beans provided nitrogen derived from nitrogen-fixing rhizobia bacteria which live on the roots of beans and other legumes; and squashes provided ground cover to stop weeds and inhibit evaporation by providing shade over the soil. This method was replaced by single species hill planting where each hill 60–120 cm (2.0–3.9 ft) apart was planted with three or four seeds, a method still used by home gardeners. A later technique was "checked maize", where hills were placed 40 inches apart in each direction, allowing cultivators to run through the field in two directions. In more arid lands, this was altered and seeds were planted in the bottom of 10–12 cm (3.9–4.7 in) deep furrows to collect water. Modern technique plants maize in rows which allows for cultivation while the plant is young, although the hill technique is still used in the maize fields of some Native American reservations.
In North America, fields are often planted in a two-crop rotation with a nitrogen-fixing crop, often alfalfa in cooler climates and soybeans in regions with longer summers. Sometimes a third crop, winter wheat, is added to the rotation.
Many of the maize varieties grown in the United States and Canada are hybrids. Often the varieties have beengenetically modified to tolerate glyphosate or to provide protection against natural pests. Glyphosate (trade name Roundup) is an herbicide which kills all plants except those with genetic tolerance. This genetic tolerance is very rarely found in nature.
In midwestern United States, low-till or no-till farming techniques are usually used. In low-till, fields are covered once, maybe twice, with a tillage implement either ahead of crop planting or after the previous harvest. The fields are planted and fertilized. Weeds are controlled through the use of herbicides, and no cultivation tillage is done during the growing season. This technique reduces moisture evaporation from the soil and thus provides more moisture for the crop. The technologies mentioned in the previous paragraph enable low-till and no-till farming. Weeds compete with the crop for moisture and nutrients, making them undesirable.
Before World War II, most maize in North America was harvested by hand (as it still is in most of the other countries where it is grown). This involves a large numbers of workers and associated social events (husking or shucking bees). Some one- and two-row mechanical pickers were in use, but the maize combinewas not adopted until after the War. By hand or mechanical picker, the entire ear is harvested, which then requires a separate operation of a maize sheller to remove the kernels from the ear. Whole ears of maize were often stored in corn cribs, and these whole ears are a sufficient form for some livestock feeding use. Few modern farms store maize in this manner. Most harvest the grain from the field and store it in bins. The combine with a maize head (with points and snap rolls instead of a reel) does not cut the stalk; it simply pulls the stalk down. The stalk continues downward and is crumpled in to a mangled pile on the ground. The ear of maize is too large to pass between slots in a plate as the snap rolls pull the stalk away, leaving only the ear and husk to enter the machinery. The combine separates out the husk and the cob, keeping only the kernels.
[edit]Quantity
Maize is widely cultivated throughout the world, and a greater weight of maize is produced each year than any other grain.[citation needed] The United States produces 40% of the world's harvest; other top producing countries include China, Brazil, Mexico, Indonesia, India, France and Argentina. Worldwide production was 817 million tonnes in 2009—more than rice (678 milliontonnes) or wheat (682 million tonnes).[24] In 2009, over 159 million hectares of maize were planted worldwide, with a yield of over 5 tonnes/hectare. Production can be significantly higher in certain regions of the world; 2009 forecasts for production in Iowa were 11614 kg/ha.[25][Note 2] There is conflicting evidence to support the hypothesis that maize yield potential has increased over the past few decades. This suggests that changes in yield potential are associated with leaf angle, lodging resistance, tolerance of high plant density, disease/pest tolerance, and other agronomic traits rather than increase of yield potential per individual plant.[26]
 United States | 333,010,910 | |
 China | 163,118,097 | |
 Brazil | 51,232,447 | |
 Mexico | 20,202,600 |
Maize and cornmeal (ground dried maize) constitute astaple food in many regions of the world. Introduced into Africa by the Portuguese in the 16th century, maize has become Africa's most important staple food crop.[30]Maize meal is made into a thick porridge in many cultures: from the polenta of Italy, the angu of Brazil, themămăligă of Romania, to cornmeal mush in the U.S. (and hominy grits in the South) or the food called mealie pap in South Africa and sadza, nshima and ugali in other parts of Africa. Maize meal is also used as a replacement for wheat flour, to make cornbread and other baked products. Masa (cornmeal treated with lime water) is the main ingredient for tortillas, atole and many other dishes of Mexican food.
Popcorn consists of kernels of certain varieties that explode when heated, forming fluffy pieces that are eaten as a snack. Roasted dried maize cobs with semihardened kernels, coated with a seasoning mixture of fried chopped spring onions with salt added to the oil, is a popular snack food in Vietnam. Cancha, which are roasted maize chulpe kernels, are a very popular snack food in Peru, and also appears in traditional Peruvian ceviche. An unleavened bread called makki di roti is a popular bread eaten in the Punjab region of India and Pakistan.
Chicha and chicha morada (purple chicha) are drinks typically made from particular types of maize. The first one is fermented and alcoholic, the second is a soft drink commonly drunk in Peru. Corn flakes are a common breakfast cereal in North America and the United Kingdom, and found in many other countries all over the world.
Maize can also be prepared as hominy, in which the kernels are soaked with lye in a process callednixtamalization; or grits, which are coarsely ground hominy. These are commonly eaten in theSoutheastern United States, foods handed down from Native Americans, who called the dishsagamite.
The Brazilian dessert canjica is made by boiling maize kernels in sweetened milk. Maize can also be harvested and consumed in the unripe state, when the kernels are fully grown but still soft. Unripe maize must usually be cooked to become palatable; this may be done by simply boiling or roasting the whole ears and eating the kernels right off the cob. Sweet corn, a genetic variety that is high in sugars and low in starch, is usually consumed in the unripe state. Such corn on the cob is a common dish in the United States, Canada, United Kingdom, Cyprus, some parts of South America, and the Balkans, but virtually unheard of in some European countries. Corn on the cob was hawked on the streets of early 19th-century New York City by poor, barefoot "Hot Corn Girls", who were thus the precursors of hot dog carts, churro wagons, and fruit stands seen on the streets of big cities today.[31]The cooked, unripe kernels may also be shaved off the cob and served as a vegetable in side dishes, salads, garnishes, etc. Alternatively, the raw unripe kernels may also be grated off the cobs and processed into a variety of cooked dishes, such as maize purée,tamales, pamonhas, curau, cakes, ice creams, etc.
Maize is a major source of starch.Cornstarch (maize flour) is a major ingredient in home cooking and in many industrialized food products. Maize is also a major source of cooking oil (corn oil) and of maize gluten. Maize starch can behydrolyzed and enzymatically treated to produce syrups, particularly high fructosecorn syrup, a sweetener; and also fermented and distilled to produce grain alcohol. Grain alcohol from maize is traditionally the source
of Bourbon whiskey. Maize is sometimes used as the starch source for beer. Within the United States, the usage of maize for human consumption constitutes about 1/40th of the amount of grown in the country. In the United States and Canada, maize is mostly grown to feed forlivestock, as forage, silage (made by fermentation of chopped green cornstalks), or grain. Maize meal is also a significant ingredient of some commercial animal food products, such as dog food.
Maize is also used as a fish bait, called "dough balls". It is particularly popular in Europe for coarse fishing.
[edit]Alternative medicine
Stigmas from female maize flowers, popularly called corn silk, are sold asherbal supplements.
Chemicals
Starch from maize can also be made intoplastics, fabrics, adhesives, and many other chemical products.
The corn steep liquor, a plentiful watery byproduct of maize wet milling process, is widely used in the biochemical industryand research as a culture medium to grow many kinds of microorganisms.[32]
[edit]Biofuel
See also: Corn ethanol
"Feed maize" is being used increasingly for heating;[citation needed] specializedcorn stoves (similar to wood stoves) are available and use either feed maize or wood pellets to generate heat. Maize cobs are also used as a biomass fuel source. Maize is relatively cheap and home-heating furnaces have been developed which use maize kernels as a fuel. They feature a large hopper that feeds the uniformly sized maize kernels (or wood pellets or cherry pits) into the fire.
Maize is increasingly used as a feedstock for the production of ethanol fuel.[citation needed]Ethanol is mixed with gasoline to decrease the amount of pollutants emitted when used to fuel motor vehicles. High fuel prices in mid 2007 led to higher demand for ethanol, which in turn lead to higher prices paid to farmers for maize. This led to the 2007 harvest being one of the most profitable maize crops in modern history for farmers. Because of the relationship between fuel and maize, prices paid for the crop now tend to track the price of oil.[citation needed]
The price of food is affected to a certain degree by the use of maize for biofuel production. The cost of transportation, production, and marketing are a large portion (80%) of the price of food in the United States. Higher energy costs affect these costs, especially transportation. The increase in food prices the consumer has been seeing is mainly due to the higher energy cost. The effect of biofuel production on other food crop prices is indirect. Use of maize for biofuel production increases the demand, and therefore price of maize. This, in turn, results in farm acreage being diverted from other food crops to maize production. This reduces the supply of the other food crops and increases their prices.[33][34]
Maize is widely used in Germany as a feedstock for biogas plants. Here the maize is harvested, shredded then placed in silageclamps from which it is fed into the biogas plants. This process makes use of the whole plant rather than simply using the kernels as in the production of fuel ethanol.
A biomass gasification power plant in Strem near Güssing, Burgenland, Austria, began in 2005. Research is being done to makediesel out of the biogas by the Fischer Tropsch method.
Increasingly, ethanol is being used at low concentrations (10% or less) as an additive in gasoline (gasohol) for motor fuels to increase the octane rating, lower pollutants, and reduce petroleum use (what is nowadays also known as "biofuels" and has been generating an intense debate regarding the human beings' necessity of new sources of energy, on the one hand, and the need to maintain, in regions such as Latin America, the food habits and culture which has been the essence of civilizations such as the one originated in Mesoamerica; the entry, January 2008, of maize among the commercial agreements of NAFTA has increased this debate, considering the bad labor conditions of workers in the fields, and mainly the fact that NAFTA "opened the doors to the import of maize from the United States, where the farmers who grow it receive multimillion dollar subsidies and other government supports. (...) According to OXFAM UK, after NAFTA went into effect, the price of maize in Mexico fell 70% between 1994 and 2001. The number of farm jobs dropped as well: from 8.1 million in 1993 to 6.8 million in 2002. Many of those who found themselves without work were small-scale maize growers.").[35] However, introduction in the northern latitudes of the U.S. of tropical maize for biofuels, and not for human or animal consumption, may potentially alleviate this.
As a result of the U.S. federal government announcing its production target of 35 billion US gallons (130,000,000 m3) of biofuels by 2017, ethanol production will grow to 7 billion US gallons (26,000,000 m3) by 2010, up from 4.5 billion in 2006, boosting ethanol's share of maize demand in the U.S. from 22.6 percent to 36.1 percent.[36]
Some forms of the plant are occasionally grown for ornamental use in the garden. For this purpose, variegated and colored leaf forms as well as those with colorful ears are used. Size-superlative types, having reached 34 ft (10 m) tall, cobs 2 ft (61 cm) long, or 1 in (2.5 cm) kernels, have been popular for at least a century.[37][38] Corncobs can be hollowed out and treated to make inexpensive smoking pipes, first manufactured in the United States in 1869.
An unusual use for maize is to create a "corn maze" (or "maize maze") as a tourist attraction. The idea of a maize maze was introduced by Adrian Fisher, one of the most prolific designers of modern mazes, with The American Maze Company who created a maze in Pennsylvania in 1993. Traditional mazes are most commonly grown usingyew hedges, but these take several years to mature. The rapid growth of a field of maize allows a maze to be laid out using GPS at the start of a growing season and for the maize to grow tall enough to obstruct a visitor's line of sight by the start of the summer. In Canada and the U.S., these are popular in many farming communities.
Maize kernels can be used in place of sand in a sandboxlike enclosure for children's play.[39]
Additionally, feed corn is sometimes used by hunters to bait animals such as deer or wild hogs.
[edit]Fodder
Maize makes a greater quantity of epigeous mass than other cereal plants, so can be used for fodder. Digestibility and palatability are higher when ensiled and fermented, rather than dried.
[edit]Commodity
Maize is bought and sold by investors and price speculators as a tradable commodity using corn futures contracts. These "futures" are traded on the Chicago Board of Trade (CBOT) under ticker symbol C. They are delivered every year in March, May, July, September, and December.[40]
[edit]U.S. usage breakdown
The breakdown of usage of the 12.1 billion bushel 2008 U.S. maize crop was as follows, according to the World Agricultural Supply and Demand Estimates Report by the USDA.[41]
- 5,250 million bu. - livestock feed
- 3,650 million bu. - ethanol production
- 1,850 million bu. - exports
- 943 million bu. - production of starch, corn oil, sweeteners (HFCS,etc.)
- 327 million bu. - human consumption - grits, corn flour, corn meal, beverage alcohol
When maize was first introduced into farming systems other than those used by traditional native-American peoples, it was generally welcomed with enthusiasm for its productivity. However, a widespread problem of malnutrition soon arose wherever maize was introduced as a staple food. This was a mystery, since these types of malnutrition were not normally seen among the indigenous Americans, for whom maize was the principal staple food.[43]
It was eventually discovered that the indigenous Americans had learned to soak maize[citation needed] in alkali-water—made with ashes and lime (calcium oxide) byMesoamericans and North Americans—which liberates the B-vitamin niacin, the lack of which was the underlying cause of the condition known as pellagra. This alkali process is known by its Nahuatl (Aztec)-derived name: nixtamalization. Besides the lack of niacin, pellagra was also characterized by protein deficiency, a result of the inherent lack of two key amino acids in pre-modern maize, lysine and tryptophan. Nixtamalisation was also found to increase the availability of lysine and tryptophan to some extent, but more importantly, the indigenous Americans had also learned to balance their consumption of maize with beans and other protein sources such as amaranth and chia, as well as meat and fish, to acquire the complete range of amino acids for normal protein synthesis.
Maize was introduced into the diet of nonindigenous Americans without the necessary cultural knowledge acquired over thousands of years in the Americas. In the late 19th century, pellagra reached epidemic proportions in parts of the southern U.S., as medical researchers debated two theories for its origin: the deficiency theory (which was eventually shown to be true) said that pellagra was due to a deficiency of some nutrient, and the germ theory said that pellagra was caused by a germ transmitted by stable flies. In 1914, the U.S. government officially endorsed the germ theory of pellagra, but rescinded this endorsement several years later when the evidence grew against it. By the mid-1920s, the deficiency theory of pellagra was becoming scientific consensus, and the theory was validated in 1932 when niacin deficiency was determined to be the cause of the illness.
Once alkali processing and dietary variety were understood and applied, pellagra disappeared in the developed world. The development of high lysine maize and the promotion of a more balanced diet has also contributed to its demise. Pellagra still exists today in food-poor areas and refugee camps where people survive on donated maize.[44]
[edit]Allergy
Maize contains lipid transfer protein, an indigestible protein that survives cooking. This protein has been linked to a rare and understudied allergy to maize in humans.[45] The allergic reaction can cause skin rash, swelling or itching of mucous membranes, diarrhea, vomiting, asthma and, in severe cases, anaphylaxis. It is unclear how common this allergy is in the general population.
Maize has been an essential crop in theAndes since the pre-Columbian Era. TheMoche culture from Northern Peru made ceramics from earth, water, and fire. This pottery was a sacred substance, formed in significant shapes and used to represent important themes. Maize represented anthropomorphically as well as naturally.[46]
In the United States, maize ears along with tobacco leaves are carved into the capitals of columns in the U.S. Capitol building. Maize itself is sometimes used for temporary architectural detailing when the intent is to celebrate the fall season, local agricultural productivity and culture. Bundles of dried maize stalks are often displayed often along with pumpkins, gourds and straw in autumnal displays outside homes and businesses. A well-known example of architectural use is the Corn Palace in Mitchell, South Dakota, which uses cobs of colored maize to implement a mural design that is recycled annually.
A maize stalk with two ripe ears is depicted on the reverse of the Croatian 1 lipa coin, minted since 1993.[47]
- Children of the Corn, a 1977 horror short story by Stephen King (later made into a 1984 film with various sequels), is about a maize field-dwelling deity who commands the children in the town to sacrifice all of the town's adults to it.
- Cornman: American Vegetable Hero is a 2001 cult movie was about a loser who gets doused with toxic sludge from a maize field and develops the ability to communicate with ears of maize.
- Field of Dreams, a 1989 American drama-sports-fantasy film starring Kevin Costner, is about a maize farmer who plows his maize field to build a baseball diamond to host long-dead baseball players from the 1919 Chicago Black Sox.
- King Corn is a 2007 documentary about two college friends who grow an acre of Iowa maize and learn about where it will end up
- KoЯn is a popular nu metal band named after the American term for maize[48]
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