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Flax ( Linum usitatissimum), also known as common flax or linseed, is a member of the genus Linum in the family Linaceae. It is a food and fiber crop cultivated in cooler regions of the world. Textiles made from flax are known in Western countries as linen, and are traditionally used for bed sheets, underclothes, and table linen. Its oil is known as linseed oil. In addition to referring to the plant itself, the word "flax" may refer to the unspun fibers of the flax plant. The plant species is known only as a cultivated plant, and appears to have been domesticated just once from the wild species Linum bienne, called pale flax. The plants called "flax" in New Zealand are, by contrast, members of the genus Phormium.
Cultivated flax plants grow to tall, with slender stems. The leaf are glaucous green, slender lanceolate, 20–40 mm long, and 3 mm broad.
The are pure pale blue, 15–25 mm in diameter, with five petals. The fruit is a round, dry capsule 5–9 mm in diameter, containing several glossy brown shaped like an apple pip, 4–7 mm long.
Flax was cultivated extensively in ancient Egypt, where the temple walls had paintings of flowering flax, and mummies were embalmed using linen.Sekhri S. (2011) "Textbook of Fabric Science: Fundamentals to Finishing". PHI Learning Private Limited, New Delhi, p. 76 Egyptian priests wore only linen, as flax was considered a symbol of purity.Wisseman S. (2013) "Ancient Technologies and Archaeological Materials". Routledge, p. 124 Phoenicians traded Egyptian linen throughout the Mediterranean and the Ancient Rome used it for their .Buchanan R. (2012) "A Weaver's Garden: Growing Plants for Natural Dyes and Fibers". Courier Dover Publications, p. 22 As the Roman Empire declined, so did flax production. But with laws designed to publicize the hygiene of linen textiles and the health of linseed oil, Charlemagne revived the crop in the eighth century CE.Wisseman S., p.125 Eventually, Flanders became the major center of the European linen industry in the Middle Ages. In North America, colonists introduced flax, and it flourished there,Cullis C. p.275 but by the early 20th century, cheap cotton and rising farm wages had caused production of flax to become concentrated in northern Russia, which came to provide 90% of the world's output. Since then, flax has lost its importance as a commercial crop, due to the easy availability of more durable fibres. (2003) "The Oxford Encyclopedia of Economic History, Volume 1" Oxford University Press, p.303.
Flax fibers taken from the stem of the plant are two to three times as strong as cotton fibers. Additionally, flax fibers are naturally smooth and straight. Europe and North America both depended on flax for plant-based cloth until the 19th century, when cotton overtook flax as the most common plant for making Rag paper. Flax is grown on the Canadian for linseed oil, which is used as a drying oil in paints and varnishes and in products such as linoleum and .
Linseed meal, the by-product of producing linseed oil from flax seeds, is used as livestock fodder.Heuzé V., Tran G., Nozière P., Lessire M., Lebas F., 2017. Linseed meal. Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. Last updated on February 16, 2017, 16:31
Flaxseeds produce a vegetable oil known as flaxseed oil or linseed oil, which is one of the oldest commercial oils. It is an edible oil obtained by expeller pressing and sometimes followed by solvent extraction. Solvent-processed flaxseed oil has been used for many centuries as a drying oil in painting and varnishing.
Although brown flaxseed varieties may be consumed as readily as the yellow ones, and have been for thousands of years, its better-known uses are in paints, for fiber, and for cattle feed.
Three polyphenol — secoisolariciresinol diglucoside, p-coumaric acid glucoside, and ferulic acid glucoside — are present in commercial breads containing flaxseed.
Linseed meal is added to Cattle feeding as a protein supplement. It can only be added at low percentages due to the high fat content, which is unhealthy for ruminants. Compared to oilseed meal from Brassicaceae it measures as having lower nutrient values, however, good results are obtained in cattle, perhaps due to the mucilage, which may aid in slowing digestion and thus allowing more time to absorb nutrients. One study found that feeding flax seeds may increase omega-3 content in beef, while another found no differences. It might also act as a substitute to tallow in increasing marbled meat. In the US, flax-based feed for ruminants is often somewhat more expensive than other feeds on a nutrient basis. Sheep feeding on low quality forage are able to eat a large amount of linseed meal, up to 40% in one test, with positive consequences. It has been fed as supplement to water buffaloes in India, and provided a better diet than forage alone, but not as good as when substituted with soybean meal. It is considered an inferior protein supplement for swine because of its fibre, the vitamin antagonist, the high omega-3 content and its low lysine content, and can only be used in small amounts in the feed. Although it may increase the omega-3 content in eggs and meat, it is also an inferior and potentially toxic feed for poultry, although it can be used in small amounts. The meal is an adequate and traditional source of protein for rabbits at 8-10%. Its use in fish feeds is limited.
Raw, immature linseeds contain an amount of cyanogenic compounds and can be dangerous for monogastric animals such as horses or rabbits. Boiling removes the danger. This is not an issue in meal cake due to the processing temperature during oil extraction.
Flax straw left over from the harvesting of oilseed is not very nutritious; it is tough and indigestible, and is not recommended to use as ruminant fodder, although it may be used as bedding or baler as .
The use of flax fibers dates back tens of thousands of years; linen, a refined textile made from flax fibers, was worn widely by priests more than 4,000 years ago.The Sumerians: Their history, culture and character, Samuel Noah Kramer, pg.104, Industrial-scale flax fiber processing existed in antiquity. A Bronze Age factory dedicated to flax processing was discovered in Euonymeia, Greece.
The best grades are used for fabrics such as , lace, and Bed sheet. Coarser grades are used for the manufacturing of twine and rope, and historically, for canvas and webbing equipment. Flax fiber is a raw material used in the high-quality paper industry for the use of printed , rolling paper for , and .
for spinning flaxen yarn were invented by John Kendrew and Thomas Porthouse of Darlington, England, in 1787. New methods of processing flax have led to renewed interest in the use of flax as an industrial fiber.
As a percentage of total fat, flaxseeds contain 54% omega-3 fatty acids (mostly ALA), 18% omega-9 fatty acids (oleic acid), and 6% omega-6 fatty acids (linoleic acid); the seeds contain 9% saturated fat, including 5% as palmitic acid. Flaxseed oil contains 53% 18:3 omega-3 fatty acids (mostly ALA) and 13% 18:2 omega-6 fatty acids.
A meta-analysis has shown that consumption of more than 30 g of flaxseed daily for more than 12 weeks reduced body weight, body mass index (BMI), and waist circumference for persons with a BMI greater than 27. Another meta-analysis has shown that consumption of flaxseed for more than 12 weeks produced small reductions in Systole and Diastole. Flaxseed supplementation showed a small reduction in c-reactive protein (a marker of inflammation) only in persons with a BMI greater than 30.
Flax grown for seed is allowed to mature until the seed capsules are yellow and just starting to split; it is then harvested in various ways. A combine harvester may either cut only the heads of the plants, or the whole plant. These are then dried to extract the seed. The amount of weeds in the straw affects its marketability, and this, coupled with market prices, determines whether the farmer chooses to harvest the flax straw. If the flax straw is not harvested, typically, it is burned, since the stalks are quite tough and decompose slowly ( i.e., not in a single season). Formed into from the harvesting process, the straw often clogs up tillage and planting equipment. Flax straw that is not of sufficient quality for fiber uses can be baled to build shelters for farm animals, or sold as biofuel, or removed from the field in the spring.
Two ways are used to harvest flax fiber, one involving mechanized equipment (combines), and a second method, more manual and targeting maximum fiber length.
The mature plant can also be cut with mowing equipment, similar to hay harvesting, and raked into windrows. When dried sufficiently, a combine then harvests the seeds similar to wheat or oat harvesting .
Flax processing is divided into two parts: the first part is generally done by the farmer, to bring the flax fiber into a fit state for general or common purposes. This can be performed by three machines: one for threshing out the seed, one for breaking and separating the straw (stem) from the fiber, and one for further separating the broken straw and matter from the fiber.
The second part of the process brings the flax into a state for the very finest purposes, such as lace, cambric, damask, and very fine linen. This second part is performed by a refining machine.
In field retting, the flax is laid out in a large field, and dew is allowed to collect on it. This process normally takes a month or more, but is generally considered to provide the highest quality flax fibers, and it produces the least pollution.
Retting can also be done in a plastic trash can or any type of water-tight container of wood, concrete, earthenware, or plastic. Metal containers will not work, as an acid is produced when retting, and it would corrode the metal. If the water temperature is kept at , the retting process under these conditions takes 4 or 5 days. If the water is any colder, it takes longer. Scum collects at the top, and an odor is given off the same as in pond retting. 'Enzymatic' retting of flax has been researched as a technique to engineer fibers with specific properties.
Common flax is the national flower of Belarus.
In early versions of the Sleeping Beauty tale, such as "Sun, Moon, and Talia" by Giambattista Basile, the princess pricks her finger, not on a spindle, but on a sliver of flax, which later is sucked out by her children conceived as she sleeps.
Flax fibers
Flax fiber is extracted from the bast beneath the surface of the stem of the flax plant. Flax fiber is soft, lustrous, and flexible; bundles of fiber have the appearance of blonde hair, hence the description "flaxen" hair. It is stronger than cotton fiber, but less elastic.
(2015). 9789606878947, Kapon Editions. ISBN 9789606878947
Nutrition
In a 100-gram serving, flaxseed contains high levels (> 19% of the Daily Value, DV) of protein, dietary fiber, several B vitamins, and dietary minerals. Ten grams of flaxseed contains one gram of water-soluble fiber (which lowers blood cholesterol) and three grams of insoluble fiber (which helps prevent constipation). Flax contains hundreds of times more than other plant foods. Flaxseeds are especially rich in thiamine, magnesium, potassium, and phosphorus (DVs above 90%).
Health effects
One study of research published between 1990 and 2008 showed that consuming flaxseed or its derivatives may reduce total and LDL-cholesterol in the blood, with greater benefits in women and those with high cholesterol.
Linseed oil
Toxicity
Flaxseed and its oil have repeatedly been demonstrated to be nontoxic and are generally recognized as safe for human consumption. Like many common foods, flax contains small amounts of cyanogenic glycoside, which is nontoxic when consumed in typical amounts, but may be toxic when consumed in large quantities as with such as cassava. Typical concentrations (for example, 0.48% in a sample of defatted dehusked flaxseed meal) can be removed by special processing.
Cultivation
The most suitable for flax, besides the alluvial kind, are deep containing a large proportion of organic matter. Flax is often found growing just above the waterline in cranberry bogs. Heavy are unsuitable, as are soils of a or dry nature. Farming flax requires few or . Within eight weeks of sowing, the plant can reach in height, reaching within 50 days.
Diseases
Production
In 2018, world production of flax (linseed) was 3.2 million , led by Kazakhstan with 29% of the total. Other major producers were Canada, Russia, and China (table).
Harvesting
Maturation
Flax is harvested for fiber production after about 100 days, or a month after the plants flower and two weeks after the seed capsules form. The bases of the plants begin to turn yellow. If the plants are still green, the seed will not be useful, and the fiber will be underdeveloped. The fiber degrades once the plants turn brown.
Harvesting for fiber
Mechanical
Flax for fiber production is usually harvested by a specialized flax harvester. Usually built on the same machine base as a combine, but instead of the cutting head it has a flax puller. The flax plant turned over and is gripped by rubber belts roughly 20–25 cm (8-10") above ground, to avoid getting grasses and weeds in the flax. The rubber belts then pull the whole plant out of the ground with the roots so the whole length of the plant fiber can be used. The plants then pass over the machine and is placed on the field crosswise to the harvesters direction of travel. The plants are left in the field for field retting.
Manual
The plant is pulled up with the roots (not cut), so as to increase the fiber length. After this, the flax is allowed to dry, the seeds are removed, and it is then Retting. Dependent upon climatic conditions, characteristics of the sown flax and fields, the flax remains on the ground between two weeks and two months for retting. As a result of alternating rain and the sun, an enzymatic action degrades the pectins which bind fibers to the straw. The farmers turn over the straw during retting to evenly rett the stalks. When the straw is retted and sufficiently dry, it is rolled up. It is then stored by farmers before extracting the fibers.
Processing
Threshing is the process of removing the seeds from the rest of the plant. Separating the usable flax fibers from other components requires pulling the stems through a hackle and/or beating the plants to break them.
Preparation for spinning
Before the flax fibers can be spun into linen, they must be separated from the rest of the stalk. The first step in this process is retting, which is the process of rotting away the inner stalk, leaving the outer parts intact. At this point, straw, or coarse outer stem (cortex and epidermis), is still remaining. To remove this, the flax is "broken", the straw is broken up into small, short bits, while the actual fiber is left unharmed. Scutching scrapes the outer straw from the fiber. The stems are then pulled through "hackles", which act like combs to remove the straw and some shorter fibers out of the long fiber.
Retting flax
Several methods are used for retting flax. It can be retted in a pond, stream, field, or tank. When the retting is complete, the bundles of flax feel soft and slimy, and quite a few fibers are standing out from the stalks. When wrapped around a finger, the inner woody part springs away from the fibers. Pond retting is the fastest. It consists of placing the flax in a pool of water which will not evaporate. It generally takes place in a shallow pool which will warm up dramatically in the sun; the process may take from a few days to a few weeks. Pond-retted flax is traditionally considered of lower quality, possibly because the product can become dirty, and is easily over-retted, damaging the fiber. This form of retting also produces quite an odor. Stream retting is similar to pool retting, but the flax is submerged in bundles in a stream or river. This generally takes two or three weeks longer than pond retting, but the end product is less likely to be dirty, does not smell as bad, and because the water is cooler, is less likely to be over-retted. Both pond and stream retting were traditionally used less because they pollute the waters used for the process.
H V Sreenivasa Murthy (2020). 9789385059094, Woodhead Publishing India PVT LTD (2017 Revised edition). ISBN 9789385059094
Dressing the flax
Genetically modified flax contamination
In September 2009, Canadian flax exports reportedly had been contaminated by a deregistered genetically modified cultivar called 'Triffid' that had food and feed safety approval in Canada and the U.S., however, Canadian growers and the Flax Council of Canada raised concerns about the marketability of this cultivar in Europe where a zero tolerance policy exists regarding unapproved genetically modified organisms. Subsequently, deregistered in 2010 and never grown commercially in Canada or the U.S., 'Triffid' stores were destroyed, but future exports and further tests at the University of Saskatchewan proved that 'Triffid' persisted among flax crops, possibly affecting future crops. Canadian flaxseed cultivars were reconstituted with 'Triffid'-free seed used to plant the 2014 crop. Laboratories are certified to test for the presence of 'Triffid' at a level of one seed in 10,000.
Symbolic images
Flax is the emblem of Northern Ireland and displayed by the Northern Ireland Assembly. In a coronet, it appeared on the reverse of the British one-pound coin to represent Northern Ireland on coins minted in 1986, 1991, and 2014. Flax also represents Northern Ireland on the badge of the Supreme Court of the United Kingdom and on various logos associated with it.
See also
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