Buckwheat

Buckwheat (Fagopyrum esculentum) is a plant cultivated for its grain-like seeds, and also used as a cover crop. To distinguish it from a related species, Fagopyrum tataricum that is also cultivated as a grain in the Himalayas, and from the less commonly cultivated Fagopyrum acutatum, it is also known as Japanese buckwheat^[2] and silverhull buckwheat.^[2]

Despite the name, buckwheat is not related to wheat, as it is not a grass. Instead, buckwheat is related to sorrel, knotweed, and rhubarb. Because its seeds are eaten, it is referred to as a pseudocereal. The cultivation of buckwheat grain declined sharply in the 20th century with the adoption of nitrogen fertilizer that increased the productivity of other staples.

Etymology

The name 'buckwheat' or 'beech wheat' comes from its triangular seeds, which resemble the much larger seeds of the beech nut from the beech tree, and the fact that it is used like wheat. The word may be a translation of Middle Dutch boecweite: boec (Modern Dutch beuk), "beech" (see PIE *bhago-) and weite (Mod. Dut. weit), wheat, or may be a native formation on the same model as the Dutch word.^[3]

History

The wild ancestor of common buckwheat is F. esculentum ssp.ancestrale. F. homotropicum is interfertile with F. esculentum and the wild forms have a common distribution, in Yunnan. The wild ancestor of tartary buckwheat is F. tataricum ssp. potanini.^[4]

Common buckwheat was domesticated and first cultivated in inland Southeast Asia, possibly around 6000 BCE, and from there spread to Central Asia and Tibet, and then to the Middle East and Europe. Domestication most likely took place in the western Yunnan region of China.^[5] Buckwheat is documented in Europe in Finland by at least 5300 BCE ^[6] as a first sign of agriculture and in the Balkans by circa 4000 BCE in the Middle Neolithic. In Russian and Ukrainian buckwheat is called гречка (grechka) meaning of Greek, due to its introduction in the 7th century by the Byzantine Greeks, the same is the case in Russian.

The oldest known remains in China so far date to circa 2600 BCE while buckwheat pollen found in Japan dates from as early as 4000 BCE. It is the world's highest elevation domesticate, being cultivated in Yunnan on the edge of the Tibetan Plateau or on the Plateau itself. Buckwheat was one of the earliest crops introduced by Europeans to North America. Dispersal around the globe was complete by 2006, when a variety developed in Canada was widely planted in China.

Buckwheat is a short season crop that does well on low-fertility or acidic soils, but the soil must be well drained. Too much fertilizer, especially nitrogen, will reduce yields. In hot climates, it can only be grown by sowing late in the season, so that it will bloom in cooler weather. The presence of pollinators greatly increases the yield. The nectar from buckwheat flower makes a dark-colored honey. Buckwheat is sometimes used as a green manure, as a plant for erosion control, or as wildlife cover and feed.

Agricultural production

The plant has a branching root system with one primary root that reaches deeply into the moist soil.^[7] Buckwheat has triangular seeds and produces a flower that is usually white, although can also be pink or yellow.^[8] Buckwheat branches freely, as opposed to tillering or producing suckers, causing a more complete adaption to its environment than other cereal crops.^[7] The seed hull density is less than that of water, making the hull easy to remove.^[8]

Buckwheat is raised for grain where a short season is available, either because it is used as a second crop in the season, or because the climate is limiting. Buckwheat can be a reliable cover crop in summer to fit a small slot of warm season. It establishes quickly, which suppresses summer weeds.^[9] Buckwheat has a growing period of only 10–12 weeks^[10] and it can be grown in high latitude or northern areas.^[11] It grows 30 to 50  inches (75 to 125 cm) tall.^[9]

Historical data

A century ago, the Russian Empire was the world leader in buckwheat production.^[12] Growing areas in the Russian Empire were estimated at 6.5 million acres (2,600,000 ha), followed by those of France at 0.9 million acres (360,000 ha).^[13] In 1970, the Soviet Union grew an estimated 4.5 million acres (1,800,000 ha) of buckwheat. It remains in 2014 a key cereal.^[14] Production in China expanded greatly during the 2000s, to rival Russia's output.

In the northeastern United States, buckwheat was a common crop in the 18th and 19th centuries. Cultivation declined sharply in the 20th century due to the use of nitrogen fertilizer, to which maize and wheat respond strongly. Over 1,000,000 acres (400,000 ha) were harvested in the United States in 1918. By 1954, that had declined to 150,000 acres (61,000 ha), and by 1964, the last year annual production statistics were gathered by USDA, only 50,000 acres (20,000 ha) were grown. However it may benefit from an "explosion in popularity of so-called ancient grains" reported in the years 2009-2014.^[15]

Present-day production

FAO world production estimates 2013

Country	Area harvested (ha)	Production (tonnes)
Russia	905,911	833,936
China	705,000	733,000
Kazakhstan	202,008	276,840
Ukraine	168,400	179,020
USA	77,500	81,000
Poland	70,384	90,874
Japan	61,400	33,400
Brazil	48,000	62,000
France	44,500	154,800
Belarus	31,403	30,353
Lithuania	30,500	28,200
Nepal	10,681	10,056
Tanzania	10,500	10,500
Latvia	9,800	10,800
Bhutan	3,000	4,500
Korea	2,392	1,923
Slovenia	1,401	1,052
Czech Republic	1,000	2,400
Bosnia and Herzegovina	633	977
South Africa	630	250
Estonia	600	400
Croatia	190	390
Hungary	110	110
Georgia	100	100
Slovakia	92	68
Republic of Moldova	61	40
Kyrgyzstan	26	25

Lists of countries by agricultural output rankings Cereals Barley Buckwheat Maize Millet Oats Rice Rye Sorghum Triticale Wheat Fruit Apples Apricots Bananas Citrus Oranges Plums Pear Grapes Mango Tomatoes Vegetables Artichoke Onion Potato Rapeseed Soybean Cucumber Other Cacao Cassava Coffee Fish Garlic Milk Sugar beet Sugar cane Sunflower seed Tea Tobacco Wine Related Irrigation Land use List of international rankings List of top international rankings by country Lists by country

Chemical composition

Seeds

Starch

• 71–78% in groats
• 70–91% in different types of flour^[16][17][18]
• Starch is 25% amylose and 75% amylopectin.
• Depending on hydrothermal treatment, buckwheat groats contain 7–37% of resistant starch.

Proteins

• Crude protein is 18%, with biological values above 90%.^[19] This can be explained by a high concentration of all essential amino acids,^[20] especially lysine, threonine, tryptophan, and the sulphur-containing amino acids.^[21]

Minerals

• Rich in iron (60–100 ppm), zinc (20–30 ppm) and selenium (20–50 ppb)^[22][23]

Antioxidants in the form of phenolics

• 10–200 ppm of rutin, 0.1–2% of tannins^[24] and presence of catechin-7-O-glucoside in groats.^[25]

Aromatic compounds

Salicylaldehyde (2-hydroxybenzaldehyde) was identified as a characteristic component of buckwheat aroma.^[26] 2,5-dimethyl-4-hydroxy-3(2H)-furanone, (E,E)-2,4-decadienal, phenylacetaldehyde, 2-methoxy-4-vinylphenol, (E)-2-nonenal, decanal and hexanal also contribute to its aroma. They all have odour activity value more than 50, but the aroma of these substances in an isolated state does not resemble buckwheat.^[27]

Inositol derivatives

Fagopyritol A1 and fagopyritol B1 (mono-galactosyl D-chiro-inositol isomers), fagopyritol A2 and fagopyritol B2 (di-galactosyl D-chiro-inositol isomers), and fagopyritol B3 (tri-galactosyl D-chiro-inositol)^[28]

Herb

Antioxidants

• 1–10% rutin and 1–10% tannins^[29]

Fagopyrin

• 0.4 to 0.6 mg/g of fagopyrins (at least 3 similar substances)^[30][31]

Use

Food

The fruit is an achene, similar to sunflower seed, with a single seed inside a hard outer hull. The starchy endosperm is white and makes up most or all of buckwheat flour. The seed coat is green or tan, which darkens buckwheat flour. The hull is dark brown or black, and some may be included in buckwheat flour as dark specks. The dark flour is known as blé noir (black wheat) in French, along with the name sarrasin (saracen).

Buckwheat noodles have been eaten by people from Tibet and northern China for centuries, as wheat can not be grown in the mountain regions. A special press made of wood is used to press the dough into hot boiling water when making buckwheat noodles. Old presses found in Tibet and Shanxi share the same basic design features. The Japanese and Koreans may have learned the making of buckwheat noodles from them.

In India, on Hindu fasting days (Navaratri, Ekadashi, Janamashthami, and Maha Shivaratri), northern states of India eat items made of buckwheat flour. Eating cereals such as wheat or rice is prohibited during such fasting days. However, since buckwheat is not a cereal, it is considered acceptable for consumption during Hindu fasting days. While strict Hindus do not even drink water during their fast (observing nirjal upwaas), others just give up cereals and salt and take a meal prepared from non-cereal ingredients such as buckwheat (Kuttu). The preparation of buckwheat flour varies across India. The famous ones are kuttu ki puri (buckwheat pancakes) and kuttu pakoras (potato slices dipped in buckwheat flour and deep fried in oil). In most of northern and western states, buckwheat flour is called kuttu ka atta.

Buckwheat noodles play a major role in the cuisines of Japan (soba),^[32] Korea (naengmyeon, makguksu and memil guksu) and the Valtellina region of Northern Italy (pizzoccheri). Soba noodles are the subject of deep cultural importance in Japan. In Korea, guksu (noodles) were widely made from buckwheat before it was replaced by wheat. The difficulty of making noodles from flour with no gluten has resulted in a traditional art developed around their manufacture by hand.

Buckwheat groats are commonly used in western Asia and eastern Europe. The porridge was common, and is often considered the definitive peasant dish. It is made from roasted groats that are cooked with broth to a texture similar to rice or bulgur. The dish was brought to America by Ukrainian, Russian and Polish immigrants who called it kasha, and they mixed it with pasta or used it as a filling for cabbage rolls, knishes and blintzes, and hence buckwheat prepared in this fashion is most commonly called "kasha" in America. Groats were the most widely used form of buckwheat worldwide during the 20th century, eaten primarily in Estonia, Russia, Ukraine and Poland, called "grechka" in Ukrainian or Russian. The groats can also be sprouted and then eaten raw or cooked.

Buckwheat pancakes, sometimes raised with yeast, are eaten in several countries. They are known as buckwheat blinis in Russia, galettes in France (savoury crêpes made with buckwheat flour, water and eggs are associated with Lower Brittany, whilst savoury galettes made without eggs are from Higher Brittany), ployes in Acadia and boûketes (which are named after the buckwheat plant) in the Wallonia region of Belgium. Similar pancakes were a common food in American pioneer days.^[33] They are light and foamy. The buckwheat flour gives them an earthy, mildly mushroom-like taste. In Ukraine, yeast rolls called hrechanyky are made from buckwheat. Buckwheat flour is also used to make Nepali dishes like "dhedo" and "kachhyamba".

Farina made from groats are used for breakfast food, porridge, and thickening materials in soups, gravies, and dressings. In Korea, buckwheat starch is used to make a jelly called memilmuk. It is also used with wheat, maize (polenta taragna in Northern Italy) or rice in bread and pasta products.

Buckwheat contains no gluten^[34] and can consequently be eaten by people with coeliac disease or gluten allergies. Many bread-like preparations have been developed.

Buckwheat is a good honey plant, producing a dark, strong^[35] monofloral honey.

Negative reactions

Buckwheat can be a potent allergen. In sensitive people, it provokes IgE-mediated anaphylaxis.^[36] The cases of anaphylaxis induced by buckwheat ingestion have been reported in Korea, Japan and Europe, where it is more often described as a "hidden allergen".^[37][38] A recent article by Heffler et al. showed allergic reactions, even severe ones, induced by accidental ingestion of buckwheat as "hidden allergy", are not so rare as previously described.^[39]

Light sensitivity, called "fagopyrism," can result from the fagopyrin in buckwheat. The symptoms are a rash on exposure to sunlight. Buckwheat leaves contain far more fagopyrin than the grain, so this condition primarily occurs in animals that graze buckwheat, but has also been reported from people who eat large amounts of buckwheat sprouts, or drink buckwheat-sprout juice.

Beer

In recent years, buckwheat has been used as a substitute for other grains in gluten-free beer. Although it is not an actual cereal (being a pseudocereal), buckwheat can be used in the same way as barley to produce a malt that can form the basis of a mash that will brew a beer without gliadin or hordein (together gluten) and therefore can be suitable for coeliacs or others sensitive to certain glycoproteins.^[40]

Whisky

A buckwheat only whisky, Eddu Silver^[41] and Eddu Gold, is distilled by the French Distillerie des Menhirs^[42] in Brittany near Quimper. The buckwheat is malted and fermented similar to buckwheat beer but is then distilled and aged in French oak casks.^[43] A blended whisky, Eddu Grey Rock,^[44] is also produced. Ed-du is Breton for buckwheat.

Upholstery filling

Buckwheat hulls are used as filling for a variety of upholstered goods, including pillows and zafu. The hulls are durable and do not conduct or reflect heat as much as synthetic fills. They are sometimes marketed as an alternative natural fill to feathers for those with allergies. However, medical studies to measure the health effects of buckwheat hull pillows manufactured with unprocessed and uncleaned hulls, concluded such buckwheat pillows do contain higher levels of a potential allergen that may trigger asthma in susceptible individuals than do new synthetic-filled pillows.^[45][46]

Biological control

Buckwheat is currently being studied and used as a pollen and nectar source to increase natural predator numbers to control crop pests in New Zealand.^[47]

Cultural

The buckwheat plant is celebrated in Kingwood, West Virginia at the Preston County Buckwheat Festival, where people can participate in swine, cattle, and sheep judging contests, vegetable contests, and craft fairs. The area fire departments also play an important role in the series of parades that occur there. Each year there is a King Buckwheat and Queen Ceres elected. Also there are many rides, and homemade, homegrown buckwheat cakes and sausage are served.

Medicinal uses

Buckwheat contains a glucoside called rutin, a phytochemical that strengthens capillary walls.^[48] One clinical study showed mixed results in the treatment of chronic venous insufficiency.^[49] Dried buckwheat leaves were manufactured in Europe under the brand name "Fagorutin" for use as an herbal tea.

It also contains galloylated propelargonidins and procyanidins.^[50]

Buckwheat contains D-chiro-inositol, a component of the secondary messenger pathway for insulin signal transduction found to be deficient in Type II diabetes and polycystic ovary syndrome. It is being studied for use in treating Type II diabetes.^{[51] [52]}

Research on D-chiro-inositol and PCOS has shown promising results.^[53][54]

High protein buckwheat flour is being studied for possible use as a functional ingredient in foods to reduce plasma cholesterol, body fat, and cholesterol gallstones.^[55]

See also

• Eriogonum, a genus of wild North American plants also known as buckwheat

References

Further reading

• E.S. Oplinger, E.A. Oelke, M.A. Brinkman and K.A. Kelling (November 1989). "Buckwheat". Alternative Field Crops Manual. Retrieved 2008-02-26. 
• Damania, A.B. (1998). "Diversity of Major Cultivated Plants Domesticated in the Near East". Proceedings of the Harlan Symposium. 
• Chun H.N., Chung C.K., Kang I.J., Kim E.R., Kim Y.S. (2003). "Effect of Germination on the Nutritional Value of Buckwheat Seed". Division of Life Sciences at Hallym University, South Korea. 
• Mazza, G. (1992). "Buckwheat (Fagopyrum esculentum), the crop and its importance". In MacRae, R. Encyclopedia of food science, food technology and nutrition. London: Academic Press Ltd. pp. 534–9. 
• Mazza, G. (1993). "Storage, Processing, and Quality Aspects of Buckwheat Seed". In Janick J., Simon J.E. New crops. New York: Wiley. pp. 251–5. 
• Marshall, H.G. and Y. Pomeranz. (1982). "Buckwheat description, breeding, production and utilization". In Y. Pomeranz. Advances in cereal science and technology. St. Paul, MN.: Amer. Assoc. Cereal Chem. pp. 157–212. 
• McGregor, S.E. (1976). "9 Crop Plants and Exotic Plants — Buckwheat". Insect Pollination Of Cultivated Crop Plants. U.S. Department of Agriculture.  As found on the website of the Carl Hayden Bee Research Center of the USDA Agricultural Research Service.

• Multilingual taxonomic information from the University of Melbourne
• Clayton G. Campbell (1997). Buckwheat Fagopyrum esculentum Moench. Promoting the conservation and use of underutilized and neglected crops. 19. International Plant Genetic Resources Institute, Rome, Italy. 

External links

Wikimedia Commons has media related to Fagopyrum esculentum (Buckwheat).

Wikisource has the text of the 1911 Encyclopædia Britannica article Buckwheat.

• Descriptors for Buckwheat (Fagopyrum spp.)
• Nutritional information for buckwheat
• Buckwheat (Fagopyrum spp.)
• Lnmcp.mf.uni-lj.si: Fagopyrum Journal Archive

Recipes

• "Buckwheat pancakes". BBC. Retrieved 2014-04-06. 
• "Buckwheat noodles with smoked salmon and dill". BBC. Retrieved 2014-04-06. 

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