Rice
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- For other uses, see Rice (disambiguation).
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| Image:US long grain rice.jpg Mature seedheads of American long grain rice | ||||||||||||||
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| Oryza sativa L. |
Rice (Oryza sativa) is a species of grass in the genus Oryza, native to tropical and subtropical southeastern Asia, where it grows in wetlands. It is an annual plant, growing to 1-1.8 m tall, occasionally more, with long slender leaves 50-100 cm long and 2-2.5 cm broad. The small wind-pollinated flowers are produced in a branched arching to pendulous inflorescence 30-50 cm long. The seed is a grain (caryopsis) 5-12 mm long and 2-3 mm thick.
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Rice cultivation
Rice is a dietary staple of more than half of the world's human population, making it the most consumed cereal grain. Rice cultivation is well suited to countries and regions with low labor costs and high rainfall, as it is very labor-intensive to cultivate and requires plenty of water for irrigation. However, it can be grown practically anywhere, even on steep hillsides. Rice is the world's third largest crop, behind maize (corn) and wheat. Although its species are native to South Asia and certain parts of Africa, centuries of trade and exportation has made it commonplace in many cultures.
Rice is often grown in paddies — shallow puddles carefully controlled to ensure the appropriate water depth (typically 15 cm). Rice paddies sometimes serve a dual agricultural purpose by also producing edible fish or frogs, a useful source of protein. The farmers take advantage of the rice plant's tolerance to water: the water in the paddies prevents weeds from outgrowing the crop. Once the rice has established dominance of the field, the water can be drained in preparation for harvest. Paddies increase productivity, although rice can also be grown on dry land (including on terraced hillsides) with the help of chemical weed controls.
In some instances, a deepwater strain of rice often called floating rice is grown. This can develop elongated stems capable of coping with water depths exceeding 2 meters (6 feet).
Rice paddies are an important habitat for birds such as herons and warblers, and a wide range of amphibians and snakes. They perform a useful function in controlling insect pests.
Whether it is grown in paddies or on dry land, rice requires a great amount of water compared to other food crops. Rice growing is a controversial practice in some areas, particularly in the United States and Australia, where rice farmers use 7% of the nation's water to generate just 0.02% of GDP. However, in nations that have a periodical rain season and typhoons, rice paddies serve to keep the water supply steady and prevent floods from reaching a dangerous level.
Rice blast, caused by the fungus Magnaporthe grisea is the most significant disease affecting rice cultivation.
Preparation as food
Image:RICE POLISHING BY FOOT POWER.jpg The seeds of the rice plant are first milled to remove the outer husks of the grain; this creates brown rice. This process may be continued, removing the germ and the rest of the husk, called bran at this point, creating white rice. The white rice may then be buffed with glucose or talc powder (often called polished rice), parboiled, or processed into flour. The white rice may also be enriched to add nutrients, especially those lost during the milling process. While the cheapest method of enriching involves adding a powdered blend of nutrients that will easily wash off (in the United States, rice which has been so treated requires a label warning against rinsing), more sophisticated methods which apply nutrients directly to the grain and then coat the grain with a water insoluble substance are resistant to washing. Image:Rice-fields-Indonesia-(Java).jpg While washing is counterproductive for the powder enriched rice, it is absolutely necessary to create a better tasting and better consistency of rice when polished rice (illegal in some countries including the United States) is used.
Rice bran, called nuka in Japan, is a valuable commodity in Asia and is used for many daily needs. It is a moist inner oily layer that is heated to produce a very healthy oil. Another use is to make a kind of pickled vegetable.
The raw rice may be ground into flour for many uses as well, including making many kinds of beverages such as amazake, horchata, rice milk, and sake. Rice flour is generally safe for people on a gluten-free diet.
The processed rice seeds are usually boiled or steamed to make them edible, after which they may be fried in oil, or butter, or beaten in a tub to make mochi.
Rice, like other cereal grains, can be puffed (or popped). This process takes advantage of the grains' moisture content and typically involves heating grain pellets in a special chamber. Further puffing is sometimes accomplished by processing pre-puffed pellets in a low-pressure chamber. By the ideal gas law, one can see that both lowering the local pressure or raising the moisture temperature would result in an increase in volume prior to moisture evaporation, thus resulting in a puffy texture.
Cooking rice
See Category:Rice dishes and Wikibooks' Rice Recipes for information on food preparation using rice.
Rice is cooked by boiling it in water until it has been heated enough and has absorbed enough water to become soft and fluffy, and in some cases, sticky. This process can be done either using a measured amount of water fixed so that it is exactly enough to cook the rice, or by using excess water which is drained away once the rice is cooked. In Asia, many households expediate the cooking process using an electrical device known as a rice cooker.
Rice may be soaked prior to cooking. Like beans this will enable the rice to cook faster, and to have an improved texture due to increased expansion of the rice grains.
When preparing brown rice, a nutritionally superior method of preparation known as GABA Rice may be used. Ths involves soaking washed brown rice for 8 to 12 hours in warm water (100°F or 38°C) prior to cooking it. This process stimulates germination, which activates various enzymes in the rice. By this method, a result of the United Nations Year of Rice, it is possible to obtain a complete amino acid profile, including GABA.
History of rice cultivation
Rice cultivation is considered to have begun simultaneously in many countries over 6500 years ago. Two rice varieties were domesticated: Asian rice (Oryza sativa) and African rice (Oryza glaberrima).
It is believed that common wild rice, Oryza rufipogon, was the wild ancestor of Asian rice.[1] O. sativa appears to have originated around the foothills of the Himalayas, with O. sativa indica on the Indian side and O. sativa japonica on the Chinese side.
African rice has been cultivated for 3500 years. Between 1500 and 800 BCE, O. glaberrima propagated from its original center, the Niger River delta, and extended to Senegal. However, it never developed far from its original region. Its cultivation even declined in favor of the Asian species, possibly brought to the African continent by Arabs coming from the east coast between the 7th and 11th centuries.
Dry-land rice was introduced to Japan circa 1000 BCE. Later wet-paddy rice agriculture was brought to Japan by the Yayoi circa 300 BCE.
O. sativa was adapted to farming in the Middle East and Mediterranean Europe around 800 BCE. The Moors brought it to Spain when they conquered the country circa 700 CE. After the middle of the 15th century, rice spread throughout Italy and then France, later propagating to all the continents during the great age of European exploration. In 1694, rice arrived in South Carolina, probably originating from Madagascar. The Spanish brought rice to South America at the beginning of the 18th century.
In the United States, colonial South Carolina and Georgia grew and amassed great wealth from the slave labor obtained from the Senegambia area of West Africa. At the port of Charleston, through which 40% of all American slave imports passed, slaves from this region of Africa brought the highest prices, in recognition of their prior knowledge of rice culture, which was put to use on the many rice plantations around Georgetown, Charleston, and Savannah. From the slaves, plantation owners learned how to dike the marshes and periodically flood the fields. At first the rice was milled by hand with wooden paddles, then winnowed in sweetgrass baskets (the making of which was another skill brought by the slaves). The invention of the rice mill increased profitability of the crop, and the addition of water power for the mills in 1787 by millwright Jonathan Lucas was another step forward. Rice culture in the southeastern U.S. became less profitable with the loss of slave labor after the American Civil War, and it finally died out just after the turn of the 20th century.
World production and trade
World production of rice [2] has risen steadily from about 200 million tons of paddy rice in 1960 to 600 million tons in 2004. Milled rice is about 68% of paddy rice by weight. In the year 2004, the top three producers were China (31% of world production), India (20%), and Indonesia (9%).
World trade figures are very different, as only about 5-6% of rice produced is traded internationally. The largest three exporting countries are Thailand (26% of world exports), Vietnam (15%), and the United States (11%), while the largest three importers are Indonesia (14%), Bangladesh (4%), and Brazil (3%).
Cultivars
Rice cultivars are often classified by their grain shapes and texture. For example, Thai Jasmine rice is long-grain and relatively less sticky, as long-grain rice contains less amylopectin than short-grain cultivars. Chinese restaurants usually serve long-grain as plain unseasoned steamed rice. Japanese mochi rice and Chinese sticky rice are short-grain. Chinese people use sticky rice which is properly known as "glutinous rice" (which does not contain dietary gluten) to make zongzi. The Japanese table rice is a sticky, short-grain rice. Japanese sake rice is another kind as well.
Indian rice cultivars include long-grained and aromatic Basmati (grown in the North), long and medium-grained Patna rice and short-grained Masoori. One variety used widely in East India and South India, is usually referred to in English as parboiled rice. This is prepared by boiling the rice in large pans immediately after harvesting and before removing the husk. It is then dried, and the husk removed later. It often displays small red speckles, and has a smoky flavour from the fires. Usually the coarse variety of rice is used for this procedure. It helps to retain the natural vitamins and kill any fungi or other contaminants, but leads to a peculiar odour. This rice is easier on the stomach to digest and is mostly used by the blue collared workers. In South India, it is also used to make idlis.
Aromatic rices have definite aromas and flavors; the most noted varieties are the aforementioned basmati, and Patna rice and a hybrid variety from America sold under the trade name, Texmati. It is a genetically modified patented variety that is creating great controversy). Both Basmati and Texmati have a mild popcorn-like aroma and flavor. In Indonesia there are also red and black varieties.
High-yield cultivars of rice suitable for cultivation in Africa and other dry ecosystems called the new rice for Africa (NERICA) cultivars have been developed. It is hoped that their cultivation will improve food security in West Africa.
Scientists are working on so-called golden rice which is genetically modified to produce beta carotene, the precursor to vitamin A. This has generated a great deal of controversy over whether the amount of beta carotene would be significant and whether genetically modified foods are desirable.
Draft genomes for the two most common rice cultivars, indica and japonica, were published in April 2002. Rice was chosen as a model organism for the biology of grasses because of its relatively small genome (~430 Megabases). As a result rice was the first plant or animal to have its complete genome mapped.[3] Basmati rice is the oldest, common progenitor for most types.
International Year of Rice
On December 16, 2002, the UN General Assembly declared the year 2004 the International Year of Rice. The declaration was sponsored by Bangladesh, Brunei Darussalam, Burkina Faso, Cambodia, Cuba, Cyprus, Democratic People's Republic of Korea, Ecuador, Fiji, Gabon, Grenada, Guyana, India, Indonesia, Japan, Kazakhstan, Kuwait, Kyrgyzstan, Lao People's Democratic Republic, Madagascar, Mali, Malaysia, the Marshall Islands, Mauritania, Myanmar, Nauru, Nepal, Nicaragua, Niger, Nigeria, Papua New Guinea, Pakistan, Peru, the Philippines, Saint Vincent and the Grenadines, Singapore, Sri Lanka, Sudan, Tajikistan, Thailand, Togo, Vietnam, and Zambia.
See also
- Inari
- Indonesian rice table
- Patna rice
- protein per unit area
- rice milk
- Roma rice
- wild rice
- Bhutanese red rice
- forbidden rice
External links
General
- 2004: International Year of Rice
- Infocomm/UNCTAD
- International Rice Research Institute
- Rice Knowledge Bank
Rice in agriculture
- American Phytopathological Society: Diseases of Rice (Oryza sativa)
- FAO: Animal Feed Resources Information System, Oryza sativa
- International Rice Research Institute: Common Insect Pests of Rice
- Origin of Chinese rice cultivation
- South Carolina rice planting photos from the early 1900s
Rice as food
- Complete Recipes: Rice
- Nutrition information for cooked rice
- US Patent 6,676,983: Puffed food starch product
Rice economics
Rice genome
- n:Chinese authorities question genetically altered rice allegation
- Oryza sativa The rice genome, a "Rosetta stone" for other cereals
- Rice Genome Research Program
- Rice Genome Approaches Completion
- The Genomes of Oryza sativa: A History of Duplications
References
- ^ "(unknown — link not accessible)." Accessed August 12, 2005.
- ^ all figures from UNCTAD 1998-2002 and the International Rice Research Institute statistics (accessed September 2005)
- ^ Gillis, Justing: “Rice Genome Fully Mapped”, washingtonpost.com, August 11, 2005.
