Buckwheat refers to plants in two genera of the dicot family Polygonaceae: the Eurasian genus Fagopyrum, and the North American genus Eriogonum. The crop plant, common buckwheat, is Fagopyrum esculentum. Tartary buckwheat (F. tataricum Gaertn.) or "bitter buckwheat" is also used as a crop, but it is much less common. Despite the common name and the grain-like use of the crop, buckwheats are not grasses (and are therefore considered pseudocereals) and are not related to wheat nor other monocots. The agricultural weed known as Wild Buckwheat (Fallopia convolvulus) is in the same family, but not closely related to the crop species. Within Fagopyrum, the cultivated species are in the cymosum group, with F. cymosum L. (perennial buckwheat), F. giganteum and F. homotropicum. 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.
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 etymology of the word is explained as partial translation of Middle Dutch boecweite : boek, beech; see PIE bhago- + weite, wheat.
Common buckwheat was domesticated and first cultivated in southeast Asia, possibly around 6000 BC, and from there spread to Europe and to Central Asia and Tibet. Domestication most likely took place in the western Yunnan region of China. Buckwheat is documented in Europe in the Balkans by at least the Middle Neolithic (circa 4000 BC) and the oldest known remains in China so far date to circa 2600 BC, and buckwheat pollen has been found in Japan from as early as 4000 BC. 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.
Common buckwheat is by far the most important buckwheat species, economically, accounting for over 90% of the world's buckwheat production. A century ago, Russia was the world leader in buckwheat production. Growing areas in the Russian Empire were estimated at 6.5 million acres (26,000 km²), followed by those of France (0.9 million acres; 3,500 km²). In 1970 the Soviet Union grew an estimated 4.5 million acres (18,000 km²) of buckwheat. Today China is the world's top producer. Japan, Poland, Canada, Brazil, South Africa, and Australia also grow significant quantities of buckwheat.
In the northeastern United States, buckwheat was a common crop in the 18th and 19th centuries. Cultivation declined sharply in the 20th century due the use of nitrogen fertilizer, to which maize and wheat respond strongly. Over a million acres (4,000 km²) were harvested in the United States in 1918. By 1954 that had declined to 150,000 acres (600 km²), and by 1964, the last year that production statistics were gathered, only 50,000 acres (200 km²) were grown.
|Seeds||Starch|| 71–78% in groats|
70–91% in different types of flour.
Starch is 25% amylose and 75% amylopectin.
Depending on hydrothermal treatment buckwheat groats contain 7–37% of resistant starch.
|Proteins|| 18% with biological values above 90%.|
This can be explained by a high concentration of all essential amino acids, especially lysine, threonine, tryptophan, and the sulphur-containing amino acids.
|Minerals||Rich in iron (60–100 ppm), zinc (20–30 ppm) and selenium (20–50 ppb).|
|Antioxidants||10–200 ppm of rutin and 0.1–2% of tannins|
|Aromatic compounds||Salicylaldehyde (2-hydroxybenzaldehyde) was identified as a characteristic component of buckwheat aroma. 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 aroma of these substances in isolated state does not resemble buckwheat.|
|Herb||Antioxidants||1–10% rutin and 1–10% tannins|
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 (exaggeratedly) as "blé noir" ("black wheat") in French, along with the name sarrazin ("saracen").
Buckwheat noodles play a major role in the cuisines of Japan (soba), 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, before wheat flour being replaced for making guksu, the generic term referring to noodles, buckwheat noodles were widely eaten as hot dishes. The difficulty of making noodles from flour that has no gluten has resulted in a traditional art developed around their hand manufacture.
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 Russian and Polish Jewish immigrants who called it "kasha" and used it mixed with pasta or as a filling for knishes and blintzes, and hence buckwheat groats are most commonly called kasha in America. Groats were the most widely used form of buckwheat worldwide during the 20th century, with consumption primarily in Russia, Ukraine and Poland.
Buckwheat pancakes, sometimes raised with yeast, are eaten in several countries. They are known as buckwheat blinis in Russia, galettes in France (savoury crêpes which are especially associated with Brittany), ployes in Acadia and boûketes (that is, named the same as the plant they are made of) in Wallonia. Similar pancakes were a common food in American pioneer days. 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.
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 or rice in bread and pasta products.
Buckwheat greens can be eaten. However, if consumed in sufficient quantities, the greens, or, more commonly, their juice, can induce sensitization of the skin to sunlight known as fagopyrism. Fair skinned people are particularly susceptible, as are light pigmented livestock. Enthusiasts of sprouting, however, eat the very young buckwheat sprouts (four to five days of growth) for their subtle, nutty flavour and high nutritional value. They are widely available in Japan.
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 (PCOS). It is being studied for use in treating Type II diabetes. Research on D-chiro-inositol and PCOS has shown promising results.
A buckwheat protein has been found to bind cholesterol tightly. It is being studied for reducing plasma cholesterol in people with an excess of this compound.
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.
Medical studies to measure the health effects of buckwheat hull pillows have been performed.
In recent years, buckwheat has been used as a substitute for other grain in gluten free beer. Buckwheat is 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.
In Hinduism, people eat items made of buckwheat flour in the fasting days. There are many great recipes available varying all over India. People in Rajasthan and Maharashtra call this KUTTU KA ATTA.