Wheat (''Triticum'' spp.) is a cereal grain, originally from the Levant region of the Near East but now cultivated worldwide. In 2013, world production of wheat was 713 million tons, making it the third most-produced cereal after maize (1,016 million tons) and rice (745 million tons).〔(【引用サイトリンク】url=http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID=567#ancor )〕 Wheat was the second most-produced cereal in 2009; world production in that year was 682 million tons, after maize (817 million tons), and with rice as a close third (679 million tons).
This grain is grown on more land area than any other commercial food. World trade in wheat is greater than for all other crops combined. Globally, wheat is the leading source of vegetable protein in human food, having a higher protein content than other major cereals, maize (corn) or rice.〔"(Nutrient data laboratory )". United States Department of Agriculture.〕 In terms of total production tonnages used for food, it is currently second to rice as the main human food crop and ahead of maize, after allowing for maize's more extensive use in animal feeds.
Wheat was a key factor enabling the emergence of city-based societies at the start of civilization because it was one of the first crops that could be easily cultivated on a large scale, and had the additional advantage of yielding a harvest that provides long-term storage of food. Wheat contributed to the emergence of city-states in the Asian Fertile Crescent, including the Babylonian and Assyrian empires. Wheat grain is a staple food used to make flour for leavened, flat and steamed breads, biscuits, cookies, cakes, breakfast cereal, pasta, noodles, couscous〔Cauvain, Stanley P. & Cauvain P. Cauvain. (2003) ''Bread Making''. CRC Press. p. 540. ISBN 1-85573-553-9.〕 and for fermentation to make beer,〔Palmer, John J. (2001) ''How to Brew''. Defenestrative Pub Co. p. 233. ISBN 0-9710579-0-7.〕 other alcoholic beverages,〔Neill, Richard. (2002) ''Booze: The Drinks Bible for the 21st Century''. Octopus Publishing Group – Cassell Illustrated. p. 112. ISBN 1-84188-196-1.〕 and biofuel.〔''Department of Agriculture Appropriations for 1957: Hearings ... 84th Congress. 2d Session''. ''United States House Committee on Appropriations''. 1956. p. 242.〕
There are six wheat classifications: 1) hard red winter, 2) hard red spring, 3) soft red winter, 4) durum (hard), 5) hard white, and 6) soft white wheat.
The hard wheats have the highest gluten content and are used for making bread, rolls and all-purpose flour. The soft wheats are used for making flat bread, cakes, pastries, crackers, muffins, and
biscuits. A high percentage of wheat production in the EU is used as animal feed, often surplus to human requirements or low-quality wheat.〔http://www.feedipedia.org/node/223〕
Wheat is planted to a limited extent as a forage crop for livestock, although the straw cannot be used as feed.〔Henry, W.A. & Morrison, F.B. (1923). ''Feeds and Feeding: a handbook for the student and stockman''. The Henry-Morrison Co. Madison, Wisconsin, USA.〕 Its straw can be used as a construction material for roofing thatch.〔Smith, Albert E. (1995) ''Handbook of Weed Management Systems''. Marcel Dekker. p. 411. ISBN 0-8247-9547-4.〕〔Bridgwater, W. & Beatrice Aldrich. (1966) ''The Columbia-Viking Desk Encyclopedia''. Columbia University. p. 1959.〕 The whole grain can be milled to leave just the endosperm for white flour. The by-products of this are bran and germ. The whole grain is a concentrated source of vitamins, minerals, and protein, while the refined grain is mostly starch.
Wheat is one of the first cereals known to have been domesticated, and wheat's ability to self-pollinate greatly facilitated the selection of many distinct domesticated varieties. The archaeological record suggests that this first occurred in the regions known as the Fertile Crescent. Recent findings estimate the first domestication of wheat down to a small region of southeastern Turkey, and domesticated Einkorn wheat at Wadi el Jilat in Jordan—has been dated to 7,500-7,300 BCE.〔(Nestbitt, Mark., When and where did domesticated cereals first occur in southwest Asia? in R.T.J. Cappers & S. Bottema (Eds.) The Dawn of Farming in the Near East. Studies in Early Near Eastern Production, Subsistence, and Environment 6, 2002 (1999). Berlin, ex oriente. )〕
Cultivation and repeated harvesting and sowing of the grains of wild grasses led to the creation of domestic strains, as mutant forms ('sports') of wheat were preferentially chosen by farmers. In domesticated wheat, grains are larger, and the seeds (inside the spikelets) remain attached to the ear by a toughened rachis during harvesting. In wild strains, a more fragile rachis allows the ear to easily shatter and disperse the spikelets. Selection for these traits by farmers might not have been deliberately intended, but simply have occurred because these traits made gathering the seeds easier; nevertheless such 'incidental' selection was an important part of crop domestication. As the traits that improve wheat as a food source ''also'' involve the loss of the plant's natural seed dispersal mechanisms, highly domesticated strains of wheat cannot survive in the wild.
Cultivation of wheat began to spread beyond the Fertile Crescent after about 8000 BCE. Jared Diamond traces the spread of cultivated emmer wheat starting in the Fertile Crescent sometime before 8800 BCE. Archaeological analysis of wild ''emmer'' indicates that it was first cultivated in the southern Levant with finds dating back as far as 9600 BCE.〔(Feldman, Moshe and Kislev, Mordechai E., Israel Journal of Plant Sciences, Volume 55, Number 3 - 4 / 2007, pp. 207 - 221, ''Domestication of emmer wheat and evolution of free-threshing tetraploid wheat'' in "A Century of Wheat Research-From Wild Emmer Discovery to Genome Analysis", Published Online: 3 November 2008 )〕 Genetic analysis of wild ''einkorn'' wheat suggests that it was first grown in the Karacadag Mountains in southeastern Turkey. Dated archeological remains of einkorn wheat in settlement sites near this region, including those at Abu Hureyra in Syria, suggest the domestication of einkorn near the Karacadag Mountain Range.〔C. Michael Hogan. 2013. (''Wheat''. Encyclopedia of Earth. National Council of Science and the Environment. ) ed. Lakhdar Boukerrou〕 With the anomalous exception of two grains from Iraq ed-Dubb, the earliest carbon-14 date for einkorn wheat remains at Abu Hureyra is 7800 to 7500 years BCE.
Remains of harvested emmer from several sites near the Karacadag Range have been dated to between 8600 (at Cayonu) and 8400 BCE (Abu Hureyra), that is, in the Neolithic period. With the exception of Iraq ed-Dubb, the earliest carbon-14 dated remains of domesticated emmer wheat were found in the earliest levels of Tell Aswad, in the Damascus basin, near Mount Hermon in Syria. These remains were dated by Willem van Zeist and his assistant Johanna Bakker-Heeres to 8800 BCE. They also concluded that the settlers of Tell Aswad did not develop this form of emmer themselves, but brought the domesticated grains with them from an as yet unidentified location elsewhere.
The cultivation of emmer reached Greece, Cyprus and India by 6500 BCE, Egypt shortly after 6000 BCE, and Germany and Spain by 5000 BCE.〔Diamond J (1997) ''Guns, Germs and Steel, A short history of everybody for the last 13,000 years.'' Viking UK Random House ISBN 0-09-930278-0〕 "The early Egyptians were developers of bread and the use of the oven and developed baking into one of the first large-scale food production industries." 〔Direct quotation: Grundas ST: Chapter: Wheat: The Crop, in ''Encyclopedia of Food Sciences and Nutrition'' p6130, 2003; Elsevier Science Ltd〕 By 3000 BCE, wheat had reached England and Scandinavia. A millennium later it reached China. The first identifiable bread wheat (''Triticum aestivum'') with sufficient gluten for yeasted breads has been identified using DNA analysis in samples from a granary dating to approximately 1350 BCE at Assiros in Greek Macedonia.
From Asia, wheat continued to spread throughout Europe. In England, wheat straw (thatch) was used for roofing in the Bronze Age, and was in common use until the late 19th century.〔Belderok B ''et al.'' (2000) ''Bread-Making Quality of Wheat'' Springer p 3 ISBN 0-7923-6383-3
*(Abengoa And Dyadic Sign Ethanol R&D Agreement Posted 31 October 2006 )
*Cauvain SP, Cauvain P (2003) ''Bread Making'' CRC Press p 540 ISBN 1-85573-553-9
*Bergen R 'American wheat beers' In (''Brewing Techniques'' )
* (FAOSTAT Agricultural statistics ) 2005 data values〕
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