Barley (Hordeum vulgare), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Barley has been used as animal fodder, as a source of fermentable material for beer and certain distilled beverages, and as a component of various health foods. It is used in soups and stews, and in barley bread of various cultures. Barley grains are commonly made into malt in a traditional and ancient method of preparation.
In 2016, barley was ranked fourth among grains in quantity produced (141 million tonnes) behind maize, rice and wheat.
Biology
Barley is a member of the grass family. It is a self-pollinating, diploid species with 14 chromosomes. The wild ancestor of domesticated barley, Hordeum vulgare subsp. spontaneum, is abundant in grasslands and woodlands throughout the Fertile Crescent area of Western Asia and northeast Africa, and is abundant in disturbed habitats, roadsides and orchards. Outside this region, the wild barley is less common and is usually found in disturbed habitats. However, in a study of genome-wide diversity markers, Tibet was found to be an additional center of domestication of cultivated barley.
Domestication
Wild barley (H. spontaneum) is the ancestor of domestic barley (H. vulgare) and harbours distinctive genes, alleles and regulators with potential for resistance to abiotic or biotic stresses to cultivated barley and adaptation to climatic changes. Wild barley has a brittle spike; upon maturity, the spikelets separate, facilitating seed dispersal. Domesticated barley has nonshattering spikes, making it much easier to harvest the mature ears. The nonshattering condition is caused by a mutation in one of two tightly linked genes known as Bt1 and Bt2; many cultivars possess both mutations. The nonshattering condition is recessive, so varieties of barley that exhibit this condition are homozygous for the mutant allele.
Each plant gets a set of genes from both parents, so two copies of each gene are in every plant. If one gene copy is a nonworking mutant, but the other gene copy works, the mutation has no effect. Only when the plant is homozygous with both copies of the gene as nonworking mutants does the mutation show its effect by exhibiting the nonshattering condition.
Domestication in barley is followed by the change of key phenotypic traits at the genetic level. Little is known about the genetic variation among domesticated and wild genes in the chromosomal regions.
Spikelets are arranged in triplets which alternate along the rachis. In wild barley (and other Old World species of Hordeum), only the central spikelet is fertile, while the other two are reduced. This condition is retained in certain cultivars known as two-row barleys. A pair of mutations (one dominant, the other recessive) result in fertile lateral spikelets to produce six-row barleys. Recent genetic studies have revealed that a mutation in one gene, vrs1, is responsible for the transition from two-row to six-row barley.
Two-row barley has a lower protein content than six-row barley, thus a more fermentable sugar content. High-protein barley is best suited for animal feed. Malting barley is usually lower protein (“low grain nitrogen”, usually produced without a late fertilizer application) which shows more uniform germination, needs shorter steeping, and has less protein in the extract that can make beer cloudy. Two-row barley is traditionally used in English ale-style beers. Six-row barley is common in some American lager-style beers, especially when adjuncts such as corn and rice are used, whereas two-row malted summer barley is preferred for traditional German beers.
Hulless barley
Hulless or “naked” barley (Hordeum vulgare L. var. nudum Hook. f.) is a form of domesticated barley with an easier-to-remove hull. Naked barley is an ancient food crop, but a new industry has developed around uses of selected hulless barley to increase the digestible energy of the grain, especially for swine and poultry. Hulless barley has been investigated for several potential new applications as whole grain, and for its value-added products. These include bran and flour for multiple food applications.
Classification
In traditional classifications of barley, these morphological differences have led to different forms of barley being classified as different species. Under these classifications, two-row barley with shattering spikes (wild barley) is classified as Hordeum spontaneum K. Koch. Two-row barley with nonshattering spikes is classified as H. distichum L., six-row barley with nonshattering spikes as H. vulgare L. (or H. hexastichum L.), and six-row with shattering spikes as H. agriocrithon Åberg.
Because these differences were driven by single-gene mutations, coupled with cytological and molecular evidence, most recent classifications treat these forms as a single species, H. vulgare L.
Varieties
Barley ears of 2 races and 6 races
Among the cultivated varieties, there are:
The winter barns, resistant to cold until approximately -15 ° C that can have flat ears with two rows of grains (these rows are denominated “careers”), or cylindrical tenons with six races of grains. Winter barley varieties are planted in late September-early October, since they need to be well established before the start of winter.
Spring barns, sensitive to frost, with a shorter growth cycle, are sown in February-March.
The grain rounded and marked with a longitudinal line is presented “peeled” (complete) or in “pearls” (polished and refined).
Some varieties grown in Europe are:
Winter and 2 races: Amillis, Augusta, Campanile, Fuga, KWS Cassia…
Winter and 2 races for beer: Arcadia, Astrid, Malicorne, Vanessa…
Winter and 6 races for beer: Amistar, Atenon, Etincel, Isocel KWS Tonic, Passerel, Touareg…
Spring and 2 races: Bérénice, Galaxis, KWS Dante, Marigold, Yvette…
Spring and 2 races for beer: Arcadia, Astoria, Béatrix, Brennus, Explorer, KWS Fabienne, Névada…
Winter hybrid and 6 races: Bagoo, Hobbit, Smooth…
More than 1300 varieties of barley are registered in the European Variety Catalog.
In Spain, the Group for the Evaluation of New Varieties of Extensive Crops in Spain carries out studies with various types of cereals, among which there are numerous new types of barley. In this sense, it is worth highlighting the pioneering work carried out in the Aula Dei Experimental Station, in which the widely disseminated variety called “Albacete barley” was developed in the 1970s.
Likewise, in some countries of Latin America such as Mexico (with the variety “Esmeralda” resistant to rust）; Argentina (where the variety called “Q. Carisma” is cited）; o Bolivia, 6 local varieties of barley are developed adapted to the soil and climatic conditions of each zone.
In other countries of the world where barley is grown, the situation is similar, with many varieties encouraged by both state public institutions and companies dedicated to the marketing of selected seeds, with the peculiarity that sometimes even breweries are involved in the development of the most suitable varieties for its activity. Thus, the “Bere” varieties (developed in Scotland for the production of whiskey） can be cited; “Betzes” (from Poland and introduced in the USA in 1958); “Centennial” (Canadian variety developed by the University of Alberta）; “Cyclon” (variety cultivated in Russia, hybrid of Russian and German winter varieties); “Diamant” (Czech high-performance mutant variety created through the use of X-rays); “Drummond” (very resistant variety developed in the USA in the year 2000); “Golden Promise” (British mutant variety developed through the use of gamma radiation, suitable for the production of beer and whiskey); “Highland barley” (cultivated in the highlands of Tibet）; “Lux” (selected in Denmark); “Maris Otter” (from Great Britain, much appreciated by the producers of craft beer）; “Nordal” (variety developed by the Swedish brewery Carlsberg October November 1971); “Pinnacle”in 2006); “Windich” (originally from Australia); and “Yagan” (also Australian).
Chemistry
H. vulgare contains the phenolics caffeic acid and p-coumaric acid, the ferulic acid 8,5′-diferulic acid, the flavonoids catechin-7-O-glucoside, saponarin, catechin, procyanidin B3, procyanidin C2, and prodelphinidin B3, and the alkaloid hordenine.
History
Barley was one of the first domesticated grains in the Fertile Crescent, an area of relatively abundant water in Western Asia, and near the Nile river of northeast Africa. The grain appeared in the same time as einkorn and emmer wheat. Wild barley (H. vulgare ssp. spontaneum) ranges from North Africa and Crete in the west, to Tibet in the east. According to some scholars, the earliest evidence of wild barley in an archaeological context comes from the Epipaleolithic at Ohalo II at the southern end of the Sea of Galilee. The remains were dated to about 8500 BCE. Other scholars have written that the earliest evidence comes from Jarmo in Kurdistan (present day Iraq). Scholars believe domesticated barley (hordeum vulgare) originally spread from Central Asia to India, Persia, Mesopotamia, Syria and Egypt. Some of the earliest domesticated barley occurs at aceramic (“pre-pottery”) Neolithic sites, in the Near East such as the Pre-Pottery Neolithic B layers of Tell Abu Hureyra, in Syria. By 4200 BCE domesticated barley occurs as far as in Eastern Finland and had reached Greece and Italy around the 4th c. BCE. Barley has been grown in the Korean Peninsula since the Early Mumun Pottery Period (circa 1500–850 BCE) along with other crops such as millet, wheat, and legumes.
Barley (known as Yava in both Vedic and Classical Sanskrit) is mentioned many times in Rigveda and other Indian scriptures as one of the principal grains in ancient India. Traces of Barley cultivation have also been found in post-Neolithic Bronze Age Harappan civilization 5700–3300 years before present.
In the Pulitzer Prize-winning book Guns, Germs, and Steel, Jared Diamond proposed that the availability of barley, along with other domesticable crops and animals, in southwestern Eurasia significantly contributed to the broad historical patterns that human history has followed over approximately the last 13,000 years; i.e., why Eurasian civilizations, as a whole, have survived and conquered others.
Barley beer was probably one of the first alcoholic drinks developed by Neolithic humans. Barley later on was used as currency. The ancient Sumerian word for barley was akiti. In ancient Mesopotamia, a stalk of barley was the primary symbol of the goddess Shala. Alongside emmer wheat, barley was a staple cereal of ancient Egypt, where it was used to make bread and beer. The general name for barley is jt (hypothetically pronounced “eat”); šma (hypothetically pronounced “SHE-ma”) refers to Upper Egyptian barley and is a symbol of Upper Egypt. According to Deuteronomy 8:8, barley is one of the “Seven Species” of crops that characterize the fertility of the Promised Land of Canaan, and it has a prominent role in the Israelite sacrifices described in the Pentateuch (see e.g. Numbers 5:15). A religious importance extended into the Middle Ages in Europe, and saw barley’s use in justice, via alphitomancy and the corsned.
Rations of barley for workers appear in Linear B tablets in Mycenaean contexts at Knossos and at Mycenaean Pylos. In mainland Greece, the ritual significance of barley possibly dates back to the earliest stages of the Eleusinian Mysteries. The preparatory kykeon or mixed drink of the initiates, prepared from barley and herbs, referred in the Homeric hymn to Demeter, whose name some scholars believe meant “Barley-mother”. The practice was to dry the barley groats and roast them before preparing the porridge, according to Pliny the Elder’s Natural History (xviii.72). This produces malt that soon ferments and becomes slightly alcoholic.
Pliny also noted barley was a special food of gladiators known as hordearii, “barley-eaters”. However, by Roman times, he added that wheat had replaced barley as a staple.
Tibetan barley has been a staple food in Tibetan cuisine since the fifth century CE. This grain, along with a cool climate that permitted storage, produced a civilization that was able to raise great armies. It is made into a flour product called tsampa that is still a staple in Tibet. The flour is roasted and mixed with butter and butter tea to form a stiff dough that is eaten in small balls.
In medieval Europe, bread made from barley and rye was peasant food, while wheat products were consumed by the upper classes. Potatoes largely replaced barley in Eastern Europe in the 19th century.
Genetics
The genome of barley was sequenced in 2012, due to the efforts of the International Barley Genome Sequencing Consortium and the UK Barley Sequencing Consortium.
The genome is composed of seven pairs of nuclear chromosomes (recommended designations: 1H, 2H, 3H, 4H, 5H, 6H and 7H), and one mitochondrial and one chloroplastic chromosome, with a total of 5000 Mbp.
Abundant biological information is already freely available in several barley databases.
The wild barley (H. vulgare ssp. spontaneum) found currently in the Fertile Crescent might not be the progenitor of the barley cultivated in Eritrea and Ethiopia, indicating that separate domestication may have occurred in eastern Africa.
Production
In 2016, world production of barley was 141 million tonnes, led by the European Union producing 63% of the world total. Russia, Germany, and France were major producers.
| Country | Cultivated area (thousands ha） |
Yield (kg / ha) |
Production (Mt） |
% worldwide | |
|---|---|---|---|---|---|
| 1 | Russia | 9,002 | 2,271 | 20,444 | 14.2% |
| 2 | la France | 1,770 | 6,651 | 11,771 | 8.2% |
| 3 | Germany | 1,574 | 7,347 | 11,563 | 8.0% |
| 4 | Australia | 11,368 | 807 | 9,174 | 6.4% |
| 5 | Ukraine | 3,003 | 3,012 | 9,046 | 6.3% |
| 6 | Canada | 2,136 | 3,333 | 7 119 | 4.9% |
| 7 | Spain | 2,786 | 2,489 | 6,934 | 4.8% |
| 8 | United Kingdom | 1,080 | 6,399 | 6,911 | 4.8% |
| 9 | Turkey | 2,719 | 2,317 | 6,300 | 4.4% |
| 10 | United States | 989 | 3,893 | 3,849 | 2.7% |
| 11 | Denmark | 604 | 5,870 | 3,548 | 2.5% |
| 12 | Poland | 808 | 4,052 | 3,275 | 2.3% |
| 13 | Iran | 1,780 | 1,804 | 3,212 | 2.2% |
| 14 | Argentina | 889 | 3,264 | 2,901 | 2.0% |
| 15 | kazakhstan | 1,914 | 1,260 | 2,412 | 1.7% |
| Total world | 49,565 | 2,912 | 144,334 | 100% | |
Cultivation
Barley is a widely adaptable crop. It is currently popular in temperate areas where it is grown as a summer crop and tropical areas where it is sown as a winter crop. Its germination time is one to three days. Barley grows under cool conditions, but is not particularly winter hardy.
Barley is more tolerant of soil salinity than wheat, which might explain the increase of barley cultivation in Mesopotamia from the second millennium BCE onwards. Barley is not as cold tolerant as the winter wheats (Triticum aestivum), fall rye (Secale cereale) or winter triticale (× Triticosecale Wittm. ex A. Camus.), but may be sown as a winter crop in warmer areas of Australia and Great Britain.
Barley has a short growing season and is also relatively drought tolerant.
Plant diseases
This plant is known or likely to be susceptible to barley mild mosaic bymovirus, as well as bacterial blight. It can be susceptible to many diseases, but plant breeders have been working hard to incorporate resistance. The devastation caused by any one disease will depend upon the susceptibility of the variety being grown and the environmental conditions during disease development. Serious diseases of barley include powdery mildew caused by Blumeria graminis f.sp. hordei, leaf scald caused by Rhynchosporium secalis, barley rust caused by Puccinia hordei, crown rust caused by Puccinia coronata, and various diseases caused by Cochliobolus sativus. Barley is also susceptible to head blight.
Food
Nutrition
In a 100-g serving, raw barley provides 352 Calories and is a rich source (20% or more of the Daily Value, DV) of essential nutrients, including protein, dietary fiber, the B vitamins, niacin (31% DV) and vitamin B6 (20% DV), and several dietary minerals (table). Highest nutrient contents are for manganese (63% DV) and phosphorus (32% DV) (table). Raw barley is 78% carbohydrates, 1% fat, 10% protein, and 10% water (table).
Preparation
Hulled barley (or covered barley) is eaten after removing the inedible, fibrous, outer hull. Once removed, it is called dehulled barley (or pot barley or scotch barley). Considered a whole grain, dehulled barley still has its bran and germ, making it a nutritious and popular health food. Pearl barley (or pearled barley) is dehulled barley which has been steam processed further to remove the bran. It may be polished, a process known as “pearling”. Dehulled or pearl barley may be processed into a variety of barley products, including flour, flakes similar to oatmeal, and grits.
Barley meal, a wholemeal barley flour lighter than wheat meal but darker in colour, is used in porridge and gruel in Scotland. Barley meal gruel is known as sawiq in the Arab world. With a long history of cultivation in the Middle East, barley is used in a wide range of traditional Arabic, Assyrian, Israelite, Kurdish, and Persian foodstuffs including kashkak, kashk and murri. Barley soup is traditionally eaten during Ramadan in Saudi Arabia. Cholent or hamin (in Hebrew) is a traditional Jewish stew often eaten on Sabbath, in a variety of recipes by both Mizrachi and Ashkenazi Jews, with barley cited throughout the Hebrew Bible in multiple references. In Eastern and Central Europe, barley is also used in soups and stews such as ričet. In Africa, where it is a traditional food plant, it has the potential to improve nutrition, boost food security, foster rural development and support sustainable landcare.
The six-row variety bere is cultivated in Orkney, Shetland, Caithness and the Western Isles in the Scottish Highlands and islands. When milled into beremeal it is used locally in bread, biscuits, and the traditional beremeal bannock.
Health implications
According to Health Canada and the US Food and Drug Administration, consuming at least 3 grams per day of barley beta-glucan or 0.75 grams per serving of soluble fiber can lower levels of blood cholesterol, a risk factor for cardiovascular diseases.
Eating whole-grain barley, as well as other grains with lots of fiber, improves regulation of blood sugar (i.e., reduces blood glucose response to a meal). Consuming breakfast cereals containing barley over weeks to months also improved cholesterol levels and glucose regulation.
Like wheat, rye, and their hybrids and derivatives, barley contains gluten, which makes it an unsuitable grain for consumption by people with gluten-related disorders, such as celiac disease, non-celiac gluten sensitivity and wheat allergy sufferers, among others. Nevertheless, some wheat allergy patients can tolerate barley or rye.
Beverages
Alcoholic beverages
Barley is a key ingredient in beer and whisky production. Two-row barley is traditionally used in German and English beers. Six-row barley was traditionally used in US beers, but both varieties are in common usage now. Distilled from green beer, whiskey has been made primarily from barley in Ireland and Scotland, while other countries have used more diverse sources of alcohol, such as the more common corn, rye and wheat in the USA. In the US, a grain type may be identified on a whisky label if that type of grain constitutes 51% or more of the ingredients and certain other conditions are satisfied. About 25% of the United States’ production of barley is used for malting, for which barley is the best-suited grain.
Barley wine is a style of strong beer from the English brewing tradition. Another alcoholic drink known by the same name, enjoyed in the 18th century, was prepared by boiling barley in water, then mixing the barley water with white wine and other ingredients, such as borage, lemon and sugar. In the 19th century, a different barley wine was made prepared from recipes of ancient Greek origin.
Nonalcoholic beverages
Nonalcoholic drinks such as barley water and roasted barley tea have been made by boiling barley in water. In Italy, barley is also sometimes used as coffee substitute, caffè d’orzo (coffee of barley). This drink is obtained from ground, roasted barley and it is prepared as an espresso (it can be prepared using percolators, filter machines or cafetieres). It became widely used during the Fascist period and WWII, as Italy was affected by embargo and struggled to import coffee. It was also a cheaper option for poor families (often grown and roasted at home) in the period. Afterwards, it was promoted and sold as a coffee substitute for children. Nowadays, it is experiencing a revival and it can be considered some Italians’ favourite alternative to coffee when, for health reasons, caffeine drinks are not recommended.
Other uses
Animal feed
Half of the United States’ barley production is used as livestock feed. Barley is an important feed grain in many areas of the world not typically suited for maize production, especially in northern climates—for example, northern and eastern Europe. Barley is the principal feed grain in Canada, Europe, and in the northern United States. A finishing diet of barley is one of the defining characteristics of western Canadian beef used in marketing campaigns.
As of 2014, an enzymatic process can be used to make a high-protein fish feed from barley, which is suitable for carnivorous fish such as trout and salmon.
Algistatic
Barley straw, in England, is placed in mesh bags and floated in fish ponds or water gardens to help prevent algal growth without harming pond plants and animals. Barley straw has not been approved by the EPA for use as a pesticide and its effectiveness as an algae regulator in ponds has produced mixed results, with either more efficacy against phytoplankton algae versus mat-forming algae, or no significant change, during university testing in the US and the UK.
Measurement
Barley grains were used for measurement in England, there being three or four barleycorns to the inch and four or five poppy seeds to the barleycorn. The statute definition of an inch was three barleycorns, although by the 19th century, this had been superseded by standard inch measures. This unit still persists in the shoe sizes used in Britain and the USA.
As modern studies show, the actual length of a kernel of barley varies from as short as 4–7 mm (0.16–0.28 in) to as long as 12–15 mm (0.47–0.59 in) depending on the cultivar. Older sources claimed the average length of a grain of barley being 0.345 in (8.8 mm).
The barleycorn was known as arpa in Turkish, and the feudal system in Ottoman Empire employed the term arpalik, or “barley-money”, to refer to a second allowance made to officials to offset the costs of fodder for their horses.
Ornamental
A new stabilized variegated variety of H. vulgare, billed as H. vulgare varigate, has been introduced for cultivation as an ornamental and pot plant for pet cats to nibble.
Cultural
The Islamic prophet Muhammad prescribed barley (talbina) for seven diseases. It was also said to soothe and calm the bowels. Avicenna, in his 11th century work The Canon of Medicine, wrote of the healing effects of barley water, soup and broth for fevers. Additionally, barley can be roasted and turned into roasted barley tea, a popular Asian drink.
In English folklore, the figure of John Barleycorn in the folksong of the same name is a personification of barley, and of the alcoholic beverages made from it, beer and whisky. In the song, John Barleycorn is represented as suffering attacks, death, and indignities that correspond to the various stages of barley cultivation, such as reaping and malting. He may be related to older pagan gods, such as Mímir or Kvasir.
Source from Wikipedia