Buckwheat (Fagopyrum esculentum Moench) is an erect annual herb grown worldwide for its edible seed, which is used like cereal grains such as wheat or maize. For that reason, buckwheat grain is classified among the cereal grains even though it is from the Polygonaceae family and not from the Poaceae (grasses) family like proper cereals. As its composition is close to that of cereals, buckwheat grain can be used as feed for all classes of farm animals (Jansen, 2006).
The buckwheat plant yields several products and by-products (Steadman et al., 2001a):
- Buckwheat grain: the seed (actually an achene) can be used whole, dehulled (groats) or further milled to produce flour.
- Buckwheat hulls (husks): the seed pericarps resulting from the dehulling process.
- Buckwheat bran: it results from the milling of the grain. Its composition depends on whether or not the grain has been dehulled prior to milling. Bran from whole grains include hull fragments and may contain high amounts of fibre. Bran from dehulled grains can be extremely rich in protein.
- Buckwheat forage (see Buckwheat (Fagopyrum esculentum) forage datasheet)
The Tartary buckwheat (Fagopyrum tartaricum (L.) Gaertn.) is a related species from eastern Asia that is also domesticated. Its seeds are more bitter than those of the common buckwheat, which may explain its lesser popularity as food (Fabjan et al., 2003).
Morphology
Buckwheat is an erect annual herb that grows up to 1.2 m high and has an indeterminate growth habit. The root system consists in a shallow taproot and spreading secondary roots that can go 1 m deep (Kammermeyer, 2016). The stems are hollow and triangular. Its leaves are alternate, simple and entire, with stipules. Lower leaves are petiolated while upper ones are almost sessile. The leaf blade is triangular to cordate, 2-10 cm long x 2-10 cm broad. The inflorescence is an axillary or terminal cluster of flowers, combined in false racemes. The flowers are regular, small-sized, rose-red to white in colour. The fruit is a typical triangular, winged nutlet, 5-7.5 mm x 3 mm, grey-brown, dark brown to black in colour. The seed is pale green turning reddish brown almost the same size as the fruit (Jansen, 2006).
Uses
Buckwheat is primarily grown for human consumption. The grain is generally used as human food and as animal or poultry feed (Campbell, 1997). The grain is eaten whole or dehulled, cooked into porridge, ground into flour or groats depending on the intended use. The flour is used in the preparation of pancakes, biscuits, noodles ("crozets" in the French Alps), cereals, etc. Buckwheat has regained interest because of its protein is is gluten-free and thus sought after by consumers with gluten intolerance. It is reported to have prophylactic values, such as an anthelminthic effect when fed to livestock (Goncalves et al., 2016; Christa et al., 2008).
Buckwheat bran and middlings can be used to feed livestock. Buckwheat hulls have many uses. Farmers use them as fuel or to feed ruminants when the stock of buckwheat straw is exhausted. They are are a popular fill material for pillows, bean bags, and packaging containers in the food-canning industry. Other uses include the production of potash and as a source of natural colors in the food industry (Ratan et al., 2011; Zemnukhova et al., 2004; Taranenko et al., 2016).