Oat


Oat
Oats redirects here. It may mean either the common cereal oat discussed here, or any cultivated or wild species of the genus Avena.
Oat
Oat plants with inflorescences
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Poaceae
Genus: Avena
Species: A. sativa
Binomial name
Avena sativa
L. (1753)

The common oat (Avena sativa) is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other grains). While oats are suitable for human consumption as oatmeal and rolled oats, one of the most common uses is as livestock feed. Oats make up a part of the daily diet of horses, about 20% of daily intake or smaller, and are regularly fed to cattle as well. Oats are also used in some brands of dog food and chicken feed. Oat seeds are commonly marketed as cat grass to cat enthusiasts, since cats will readily harvest and eat tender young oat, wheat and some other grass sprouts.[citation needed]

Contents

Origin

The wild ancestor of Avena sativa and the closely related minor crop, A. byzantina, is the hexaploid wild oat A. sterilis. Genetic evidence shows the ancestral forms of A. sterilis grew in the Fertile Crescent of the Near East. Domesticated oats appear relatively late, and far from the Near East, in Bronze Age Europe. Oats, like rye, are usually considered a secondary crop, i.e., derived from a weed of the primary cereal domesticates wheat and barley. As these cereals spread westwards into cooler, wetter areas, this may have favoured the oat weed component, leading to its eventual domestication.[1]

Cultivation

Top Ten Oats Producers—2005
(million metric ton)
 Russia 5.1
 Canada 3.3
 United States 1.7
 Poland 1.3
 Finland 1.2
 Australia 1.1
 Germany 1.0
 Belarus 0.8
 China 0.8
 Ukraine 0.8
World Total 24.6
Source: FAO
EU figures from 2007 include Poland, Finland and Germany.

Oats are grown throughout the temperate zones. They have a lower summer heat requirement and greater tolerance of rain than other cereals, such as wheat, rye or barley, so are particularly important in areas with cool, wet summers, such as Northwest Europe; they are even being grown successfully in Iceland. Oats are an annual plant, and can be planted either in autumn (for late summer harvest) or in the spring (for early autumn harvest).

Oat output in 2005
Worldwide oat production


Uses

Closeup of oat florets (small flowers)

Oats have numerous uses in food; most commonly, they are rolled or crushed into oatmeal, or ground into fine oat flour. Oatmeal is chiefly eaten as porridge, but may also be used in a variety of baked goods, such as oatcakes, oatmeal cookies, and oat bread. Oats are also an ingredient in many cold cereals, in particular muesli and granola. Oats may also be consumed raw, and cookies with raw oats are becoming popular.

Oats are also occasionally used in several different drinks. In Britain, they are used for brewing beer. Oatmeal stout is one variety brewed using a percentage of oats for the wort. The more rarely used oat malt is produced by the Thomas Fawcett & Sons Maltings, and was used in the Maclay Oat Malt Stout before Maclays Brewery ceased independent brewing operations. A cold, sweet drink made of ground oats and milk is a popular refreshment throughout Latin America. Oatmeal caudle, made of ale and oatmeal with spices, was a traditional British drink and a favorite of Oliver Cromwell.[2][3]

Historical attitudes towards oats have varied. Oat bread was first manufactured in England, where the first oat bread factory was established in 1899. In Scotland, they were, and still are, held in high esteem, as a mainstay of the national diet.

In Scotland, a dish called sowans was made by soaking the husks from oats for a week so that the fine, floury part of the meal remained as sediment to be strained off, boiled and eaten.[4] Oats are also widely used there as a thickener in soups, as barley or rice might be used in other countries.

Oats are also commonly used as feed for horses—as crimped or rolled oats or as part of a blended food pellet. The oat hull must be crushed ("rolled" or "crimped") for the horse to digest the grain. Cattle are also fed oats, either whole, or ground into a coarse flour using a roller mill, burr mill, or hammer mill.

Oat straw is prized by cattle and horse producers as bedding, due to its soft, relatively dust-free, and absorbent nature. The straw can also be used for making corn dollies. Tied in a muslin bag, oat straw was used to soften bath water.

Oat extract can also be used to soothe skin conditions. It is the principal ingredient for the Aveeno line of products.[5]

Oat grass has been used traditionally for medicinal purposes, including to help balance the menstrual cycle, treat dysmenorrhea, and for osteoporosis and urinary tract infections.[6]

Health

Oat grains in their husks

Oats are generally considered "healthy", or a health food, being touted commercially as nutritious. The discovery of the healthy cholesterol-lowering properties has led to wider appreciation of oats as human food.

Soluble fibre

Oat bran is the outer casing of the oat. Its consumption is believed to lower LDL ("bad") cholesterol, and possibly to reduce the risk of heart disease.

Oats contain more soluble fibre than any other grain, resulting in slower digestion and an extended sensation of fullness.[citation needed] One type of soluble fibre, beta-glucans, has proven to help lower cholesterol.

After reports of research finding that dietary oats can help lower cholesterol,[7] an "oat bran craze" swept the U.S. in the late 1980s, peaking in 1989, when potato chips with added oat bran were marketed. The food fad was short-lived and faded by the early 1990s. The popularity of oatmeal and other oat products again increased after the January 1998 decision by the Food and Drug Administration (FDA), when it issued its final rule allowing a health claim to be made on the labels of foods containing soluble fibre from whole oats (oat bran, oat flour and rolled oats), noting that 3.00 grams of soluble fibre daily from these foods may reduce the risk of heart disease. To qualify for the health claim, the whole oat-containing food must provide at least 0.75 grams of soluble fibre per serving. The soluble fibre in whole oats comprises a class of polysaccharides known as beta-D-glucans.

Beta-D-glucans, usually referred to as beta-glucans, comprise a class of indigestible polysaccharides widely found in nature in sources such as grains, barley, yeast, bacteria, algae and mushrooms. In oats, barley and other cereal grains, they are located primarily in the endosperm cell wall.

Oat beta-glucan is a soluble fibre. It is a viscous polysaccharide made up of units of the monosaccharide D-glucose. Oat beta-glucan is composed of mixed-linkage polysaccharides. This means the bonds between the D-glucose or D-glucopyranosyl units are either beta-1, 3 linkages or beta-1, 4 linkages. This type of beta-glucan is also referred to as a mixed-linkage (1→3), (1→4)-beta-D-glucan. The (1→3)-linkages break up the uniform structure of the beta-D-glucan molecule and make it soluble and flexible. In comparison, the indigestible polysaccharide cellulose is also a beta-glucan, but is not soluble. The reason it is insoluble is that cellulose consists only of (1→4)-beta-D-linkages. The percentages of beta-glucan in the various whole oat products are: oat bran, greater than 5.5% and up to 23.0%; rolled oats, about 4%; and whole oat flour about 4%.

Oats, after corn (maize), have the highest lipid content of any cereal, e.g., greater than 10% for oats and as high as 17% for some maize cultivars compared to about two to three percent for wheat and most other cereals. The polar lipid content of oats (about 8–17% glycolipid and 10–20% phospholipid or a total of about 33%) is greater than that of other cereals, since much of the lipid fraction is contained within the endosperm.

Protein

Oats
Nutritional value per 100 g (3.5 oz)
Energy 1,628 kJ (389 kcal)
Carbohydrates 66.3 g
- Dietary fiber 10.6 g
Fat 6.9 g
Protein 16.9 g
Pantothenic acid (B5) 1.3 mg (26%)
Folate (vit. B9) 56 μg (14%)
Calcium 54 mg (5%)
Iron 5 mg (38%)
Magnesium 177 mg (50%)
β-glucan (soluble fiber)  4 g
Percentages are relative to US recommendations for adults.
Source: USDA Nutrient Database

Oats are the only cereal containing a globulin or legume-like protein, avenalin, as the major (80%) storage protein.[8] Globulins are characterised by solubility in dilute saline. The more typical cereal proteins, such as gluten and zein, are prolamines (prolamins). The minor protein of oat is a prolamine, avenin.

Oat protein is nearly equivalent in quality to soy protein, which has been shown by the World Health Organization to be equal to meat, milk, and egg protein.[9] The protein content of the hull-less oat kernel (groat) ranges from 12 to 24%, the highest among cereals.

Coeliac disease

Coeliac, or celiac, disease, is often associated with the ingestion of wheat, or more specifically, a group of proteins labelled prolamines, or more commonly, gluten. Oats lack many of the prolamines found in wheat; however, oats do contain avenin.[10] Avenin is a prolamine that is toxic to the intestinal mucosa of avenin-sensitive individuals, and can trigger a reaction in these coeliacs.[11]

The most recent research indicates that some cultivars of oat can be a safe part of a gluten-free diet, because different varieties of oat have different levels of toxicity.[12] Although oats do contain avenin, there are several studies suggesting that this may not be problematic for all celiacs. The first such study was published in 1995.[13] A follow-up study indicated it is safe to use oats even in a longer period.[14]

Additionally, oats are frequently processed near wheat, barley and other grains, such that they become contaminated with other glutens. Because of this, the FAO's Codex Alimentarius Commission officially lists them as a crop containing gluten. Oats from Ireland and Scotland, where less wheat is grown, are less likely to be contaminated in this way.[citation needed]

Oats are part of a gluten-free diet in, for example, Finland and Sweden. In both countries, there are "pure oat" products on the market.

Agronomy

Oats in Saskatchewan near harvest time

Oats are sown in the spring or early summer, as soon as the soil can be worked. An early start is crucial to good yields, as oats will go dormant during the summer heat. In warmer areas, oats are sown in late summer or early fall. Oats are cold-tolerant and will be unaffected by late frosts or snow.

Seeding rates

Typically, about 125 to 175 kg/hectare (between 2.75 and 3.25 bushels per acre) are sown, either broadcast, drilled, or planted using an air seeder. Lower rates are used when underseeding with a legume. Somewhat higher rates can be used on the best soils, or where there are problems with weeds. Excessive sowing rates will lead to problems with lodging and may reduce yields.

Winter oats may be grown as an off-season groundcover and plowed under in the spring as a green fertilizer, grazed as winter forage, or harvested in early summer.

Fertilizer requirements

Oats remove substantial amounts of nitrogen from the soil. They also remove phosphorus in the form of P2O5 at the rate of 0.25 pound per bushel per acre (1 bushel = 38 pounds at 12% moisture);[citation needed] Phosphate is thus applied at a rate of 30 to 40 kg/ha, or 30 to 40 lb/acre. Oats remove potash (K2O) at a rate of 0.19 pound per bushel per acre, which causes it to use 15–30 kg/ha, or 13–27 lb/acre. Usually, 50–100 kg/ha (45–90 pounds per acre) of nitrogen in the form of urea or anhydrous ammonia is sufficient, as oats use about one pound per bushel per acre. A sufficient amount of nitrogen is particularly important for plant height, and hence, straw quality and yield. When the prior-year crop was a legume, or where ample manure is applied, nitrogen rates can be reduced somewhat.

Weed control

The vigorous growth habit of oats will tend to choke out most weeds. A few tall broadleaf weeds, such as ragweed, goosegrass, wild mustard and buttonweed (velvetleaf), can occasionally be a problem, as they complicate harvest and reduce yields. These can be controlled with a modest application of a broadleaf herbicide, such as 2,4-D, while the weeds are still small.

Pests and diseases

Oats are relatively free from diseases and pests with the exception of the Andrew, such as leaf rust and stem rust. A few lepidopteran caterpillars feed on the plants—e.g. rustic shoulder-knot and setaceous Hebrew character moths, but these rarely become a major pest. See also List of oats diseases.

Harvesting

Harvesting of oats in Jølster, Norway ca. 1890.
(Photo: Axel Lindahl/Norwegian Museum of Cultural History)

Modern harvest technique is a matter of available equipment, local tradition, and priorities. Farmers seeking the highest yield from their crop time their harvest so the kernels have reached 35% moisture, or when the greenest kernels are just turning cream-color. They then harvest by swathing, cutting the plants at about 10 cm (4 inches) above ground, and putting the swathed plants into windrows with the grain all oriented the same way. They leave the windrows to dry in the sun for several days before combining them using a pickup header. Finally, they bale the straw.

Oats can also be left standing until completely ripe and then combined with a grain head. This will lead to greater field losses, as the grain falls from the heads, and to harvesting losses, as the grain is threshed out by the reel. Without a draper head, there will also be somewhat more age to the straw, since it will not be properly oriented as it enters the throat of the combine. Overall yield loss is 10–15% compared to proper swathing.

Historical harvest methods involved cutting with a scythe or sickle, and threshing under the feet of cattle. Late 19th and early 20th century harvesting was performed using a binder. Oats were gathered into shocks and then collected and run through a stationary threshing machine.

Storage

After combining, the oats are transported to the farmyard using a grain truck, semi, or road train, where they are augered or conveyed into a bin for storage. Sometimes, when there is not enough bin space, they are augered into portable grain rings, or piled on the ground. Oats can be safely stored at 12% moisture; at higher moisture levels, they must be aerated, or dried.

Yield and quality

In the United States, No.1 oats weigh 42 lb per bushel; No.3 oats must weigh at least 38 lb/bu. If over 36 lb/bu, they are graded as No.4, and oats under 36 lb/bu are graded as "light weight". In Canada, No.1 oats weigh 42.64 lb per bushel; No.2 oats must weigh 40.18 lb per bushel; No.3 oats must weigh at least 38.54 lb per bushel and if oats are lighter than 36.08 lb per bushel they do not make No.4 oats and have no grade.[15]

Note, however, that oats are bought and sold, and yields are figured, on the basis of a bushel equal to 32 lb in the United States and a bushel equal to 34 lb in Canada. Yields range from 60 to 80 bushels per acre on marginal land, to 100 to 150 bushels per acre on high-producing land. The average production is 100 bushels per acre, or 3.5 tonnes per hectare.

Straw yields are variable, ranging from one to three tonnes per hectare, mainly due to available nutrients, and the variety used (some are short-strawed, meant specifically for straight combining).

Processing

Porridge oats before cooking

Oats processing is a relatively simple process:

Cleaning and sizing

Upon delivery to the milling plant, chaff, rocks, other grains, and other foreign material are removed from the oats.

Dehulling

Separation of the outer hull from the inner oat groat is effected by means of centripetal acceleration. Oats are fed by gravity onto the center of a horizontally spinning stone, which accelerates them towards the outer ring. Groats and hulls are separated on impact with this ring. The lighter oat hulls are then aspirated away, while the denser oat groats are taken to the next step of processing. Oat hulls can be used as feed, processed further into insoluble oat fiber, or used as a biomass fuel.

Kilning

The unsized oat groats will then pass through a heat and moisture treatment to balance moisture, but mainly to stabilize them. Oat groats are high in fat (lipids), and once removed from their protective hulls and exposed to air, enzymatic (lipase) activity begins to break down the fat into free fatty acids, ultimately causing an off flavor or rancidity. Oats will begin to show signs of enzymatic rancidity within four days of being dehulled if not stabilized. This process is primarily done in food grade plants, not in feed grade plants. Groats are not considered raw if they have gone through this process; the heat has disrupted the germ, and they will not sprout.

Sizing of groats

Many whole oat groats are broken during the dehulling process, leaving the following types of groats to be sized and separated for further processing: whole oat groats, coarse steel cut groats, steel cut groats and fine steel cut groats. Groats are sized and separated using screens, shakers and indent screens. After the whole oat groats are separated, the remaining broken groats get sized again into the 3 groups (coarse, regular, fine), and then stored. The term steel cut is referred to all sized or cut groats. When there are not enough broken to size for further processing, then whole oat groats get sent to a cutting unit with steel blades that will evenly cut the groats into the three sizes as discussed earlier.

Final processing

Three methods are used to make the finished product:

Flaking

This process uses two large smooth or corrugated rolls spinning at the same speed in opposite directions at a controlled distance. Oat flakes, also known as rolled oats, have many different sizes, thicknesses and other characteristics depending on the size of oat groats passed between the rolls. Typically, the three sizes of steel cut oats are used to make instant, baby and quick rolled oats, whereas whole oat groats are used to make regular, medium and thick rolled oats. Oat flakes range from a thickness of 0.36 mm to 1.00 mm.

Oat bran milling

This process takes the oat groats through several roll stands to flatten and separate the bran from the flour (endosperm). The two separate products (flour and bran) get sifted through a gyrating sifter screen to further separate them. The final products are oat bran and debranned oat flour.

Whole flour milling

This process takes oat groats straight to a grinding unit (stone or hammer mill) and then over sifter screens to separate the coarse flour and final whole oat flour. The coarser flour gets sent back to the grinding unit until it is ground fine enough to be whole oat flour. This method is used often in India and other countries.

Naming

In Scottish English, oats may be referred to as corn.[16]

Oats futures

Oats futures are traded on the Chicago Board of Trade, and have delivery dates in March (H), May (K), July (N), September (U) and December (Z).[17] Oat futures contracts are traded in units of 5,000 bushels of oats and the minimum fluctuation is 1⁄4 cent per bushel ($12.50 per contract), including spreads. There are also daily price limits set such that there will be no trading beyond $0.20 per bushel ($1,000 per contract) above or below the previous day’s settlement price. [18]

See also

References

  1. ^ Zhou, X., Jellen, E.N., Murphy, J.P. 1999. Progenitor germplasm of domesticated hexaploid oat. Crop science 39: 1208–1214.
  2. ^ The Compleat Housewife, p. 169, Eliza Smith, 1739
  3. ^ Food in Early Modern Europe, Ken Albala, Greenwood Publishing Group, 2003, ISBN 0313319626
  4. ^ Gauldie, Enid (1981). The Scottish country miller, 1700–1900: a history of water-powered meal milling in Scotland. Edinburgh: J. Donald. ISBN 0-85976-067-7. 
  5. ^ "AVEENO Skin Care Products". Aveeno.com. http://www.aveeno.com/about-aveeno.jsp. Retrieved 2009-08-10. [dead link]
  6. ^ James A. Duke, Handbook of medicinal herbs, CRC Press, 2002.
  7. ^ [1]
  8. ^ http://www.plantcell.org/cgi/reprint/7/7/945.pdf
  9. ^ Lasztity, Radomir (1999). The Chemistry of Cereal Proteins. Akademiai Kiado (English). ISBN 978-0849327636. 
  10. ^ Rottmann LH (2006-09-26). "On the Use of Oats in the Gluten-Free Diet". Celiac Sprue Association/United States of America, Inc. (CSA). Archived from the original on 2006-06-05. http://web.archive.org/web/20060605170458/http://www.csaceliacs.org/library/useofoats.php. Retrieved 2006-10-31. 
  11. ^ "Info on Oats". Celiac Sprue Association/United States of America, Inc. (CSA). 2006-09-26. http://www.csaceliacs.org/InfoonOats.php. Retrieved 2007-09-29. 
  12. ^ Comino, Isabel; Ana Real, Laura de Lorenzo, Hugh Cornell, Miguel Ángel López-Casado, Francisco Barro, Pedro Lorite, Ma Isabel Torres, Ángel Cebolla, Carolina Sousa (12). "Diversity in oat potential immunogenicity: basis for the selection of oat varieties with no toxicity in coeliac disease". Gut (First Online). http://gut.bmj.com/content/early/2011/02/11/gut.2010.225268.abstract. Retrieved 12 March 2011. 
  13. ^ Janatuinen, E., et al. (1995-10-19). "A Comparison of Diets with and without Oats in Adults with Celiac Disease". New England Journal of Medicine. http://content.nejm.org/cgi/content/abstract/333/16/1033. 
  14. ^ Janatuinen, E.K., Kemppainen, T.A., Julkunen, R.J.K., Kosma, V-M., Mäki, M., Heikkinen, M. and Uusitupa, M.I. (2002) No harm from five year ingestion of oats in celiac disease, Gut, 50, 332–335
  15. ^ http://www.grainscanada.gc.ca/oggg-gocg/07/oggg-gocg-7e-eng.htm
  16. ^ Partridge, Eric; Janet Whitcut (ed.) (1995). Usage and Abusage: A Guide to Good English (1st American ed. ed.). New York: W.W. Norton, 1995. pp. 82. ISBN 0393037614. http://books.google.com/books?id=icnKIlILT4oC&pg=PA82&vq=corn&source=gbs_search_r&cad=1_1&sig=gDb63y1bG3c40htw8rMw_1_v4GI. 
  17. ^ List of Commodity Delivery Dates on Wikinvest
  18. ^ Cannon Trading, Inc. Oat Futures. Accessed September 10, 2011

External links


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Look at other dictionaries:

  • Oat — ([=o]t), n.; pl. {Oats} ([=o]ts). [OE. ote, ate, AS. [=a]ta, akin to Fries. oat. Of uncertain origin.] 1. (Bot.) A well known cereal grass ({Avena sativa}), and its edible grain, used as food and fodder; commonly used in the plural and in a… …   The Collaborative International Dictionary of English

  • oat — oat·en; oat·er; oat; …   English syllables

  • oat|en — «OH tuhn», adjective. 1. made of oats or oatmeal: »an oaten cake. 2. made of oat straw: »his oaten pype (Edmund Spenser). 3. of or having to do with the oat: »oaten straws (Shakespeare) …   Useful english dictionary

  • oat — [əut US out] adj [only before noun] made of ↑oats ▪ oat biscuits …   Dictionary of contemporary English

  • oat — (n.) O.E. ate (pl. atan) grain of the oat plant, wild oats, of uncertain origin, possibly from O.N. eitill nodule, denoting a single grain, of unknown origin. The English word has cognates in Frisian and some Dutch dialects. The usual Germanic… …   Etymology dictionary

  • oat — [ōt] n. [ME ote < OE ate: not found in other Gmc languages: prob. < IE base * oid , to swell > Russ jádrica, groats] 1. [usually pl.] a) a hardy, widely grown cereal grass (Avena sativa) b) the edible grain of this grass 2. any of… …   English World dictionary

  • OAT — (für Occluded Artery Trial) ist das Akronym einer im November 2006 auf dem jährlichen Kongress der American Heart Association vorgestellten und im The New England Journal of Medicine publizierten Studie über den Nutzen einer… …   Deutsch Wikipedia

  • oat — ► NOUN ▪ a cereal plant with a loose branched cluster of florets, cultivated in cool climates. ● feel one s oats Cf. ↑feel one s oats ● get one s oats Cf. ↑get one s oats ● sow one s wild oats Cf. ↑ …   English terms dictionary

  • oat|er — «OH tuhr», noun. U.S. Slang. a motion picture or television show about the United States West; western …   Useful english dictionary

  • Oat — Obligation assimilable du Trésor Les obligations assimilables du trésor français sont généralement connues sous leur sigle : OAT. Il s agit de valeurs mobilières, principal support de la dette négociable de l État. Ce sont des emprunts que… …   Wikipédia en Français


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