| Blueberry | |
|---|---|
| Vaccinium corymbosum | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Ericales |
| Family: | Ericaceae |
| Genus: | Vaccinium |
| Section: | Cyanococcus Rydb. |
| Other Info | |
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Flower meaning: 'Wisdom' |
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Blueberries are flowering plants of the genus Vaccinium (a genus which also includes cranberries and bilberries) with indigo colored berries and are perennial. Species in the section Cyanococcus are the most common[1] fruits sold as "blueberries" and are native to North America (commercially cultivated highbush blueberries were not introduced into Europe until the 1930s).[2]
They are usually erect but sometimes prostrate shrubs varying in size from 10 centimeters (3.9 in) to 4 meters (160 in) tall. In commercial blueberry production, smaller species are known as "lowbush blueberries" (synonymous with "wild"), and the larger species are known as "highbush blueberries".
The leaves can be either deciduous or evergreen, ovate to lanceolate, and 1–8 cm (0.39–3.1 in) long and 0.5–3.5 cm (0.20–1.4 in) broad. The flowers are bell-shaped, white, pale pink or red, sometimes tinged greenish. The fruit is a berry 5–16 millimeters (0.20–0.63 in) diameter with a flared crown at the end; they are pale greenish at first, then reddish-purple, and finally dark blue when ripe. They have a sweet taste when mature, with variable acidity. Blueberry bushes typically bear fruit in the middle of the growing season: fruiting times are affected by local conditions such as altitude and latitude, so the height of the crop can vary from May to August depending upon these conditions.
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The genus Vaccinium has a mostly circumpolar distribution with species in America, Europe and Asia, but also Africa.
Many commercially sold species English common names include "blueberry" are currently classified in section Cyanococcus of the genus Vaccinium and come predominantly from North America. Many North American native species of blueberries are now also commercially grown in the Southern Hemisphere in Australia, New Zealand and South American countries.
Several other wild shrubs of the genus Vaccinium also produce commonly eaten blue berries such as the predominantly European bilberry (Vaccinium myrtillus), which in many languages has a name that means "blueberry" in English. See the Identification section for more information.
Note: habitat and range summaries are from the Flora of New Brunswick, published in 1986 by Harold R. Hinds and Plants of the Pacific Northwest coast, published in 1994 by Pojar and MacKinnon
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Some other blue-fruited species of Vaccinium:
Commercially offered "wild blueberries" are usually from species that naturally occur only in eastern and north-central North America. Other sections in the genus, native to other parts of the world, including western North America, South America, Europe, and Asia, include other wild shrubs producing similar-looking edible berries, such as huckleberries (North America) and bilberries (Europe). These species are sometimes called "blueberries" and sold as blueberry jam or other products.
The names of blue berries in languages other than English often translate as "blueberry", e.g., Scots blaeberry and Norwegian blåbær. Blaeberry, blåbær and French myrtilles usually refer to the European native bilberry (V. myrtillus), while bleuets refers to the North American blueberry.
Cyanococcus blueberries can be distinguished from the nearly identical looking bilberries by cutting them in half. Ripe blueberries have white or light green flesh, while bilberries and huckleberries are red or purple throughout. Bilberries are most often found singularly or in pairs, while blueberries are most often found in clusters.[3]
Blueberries may be cultivated, or they may be picked from semi-wild or wild bushes. In North America, the most common cultivated species is V. corymbosum, the Northern highbush blueberry. Hybrids of this with other Vaccinium species adapted to southern U.S. climates are known collectively as Southern highbush blueberries.
So-called "wild" (lowbush) blueberries, smaller than cultivated highbush ones, are prized for their intense color. The lowbush blueberry, V. angustifolium, is found from the Atlantic provinces westward to Quebec and southward to Michigan and West Virginia. In some areas, it produces natural "blueberry barrens", where it is the dominant species covering large areas. Several First Nations communities in Ontario are involved in harvesting wild blueberries. Lowbush species are fire-tolerant and blueberry production often increases following a forest fire, as the plants regenerate rapidly and benefit from removal of competing vegetation. "Wild" has been adopted as a marketing term for harvests of managed native stands of low-bush blueberries. The bushes are not planted or genetically manipulated, but they are pruned or burned over every two years, and pests are "managed".[4]
There are numerous highbush cultivars of blueberries, each of which have a unique flavor, with diversity between them. The most important blueberry breeding program has been the USDA-ARS breeding program based at Beltsville, Maryland, and Chatsworth, New Jersey. This program began when Frederick Coville of the USDA-ARS collaborated with Elizabeth Coleman White of New Jersey.[5] In the early part of the 20th century, White offered pineland residents cash for wild blueberry plants with unusually large fruit.[6] Rubel, one such wild blueberry cultivar, is the origin of many of the current hybrid cultivars.
The rabbiteye blueberry (Vaccinium virgatum syn. V. ashei) is a southern type of blueberry produced from the Carolinas to the Gulf Coast states. Other important species in North America include V. pallidum, the hillside or dryland blueberry. It is native to the eastern U.S., and common in the Appalachians and the Piedmont of the Southeast. Sparkleberry, V. arboreum, is a common wild species on sandy soils in the Southeast. Its fruits are important to wildlife, and the flowers are important to beekeepers.
Significant production of highbush blueberries occurs in British Columbia, Maryland, Western Oregon, Michigan, New Jersey, North Carolina, and Washington. The production of southern highbush varieties in California is rapidly increasing, as varieties originating from the University of Florida((Conneticut)) ((New Hampshire)) North Carolina State University and ((Maine)) have been introduced. Southern highbush berries are now also cultivated in the Mediterranean regions of Europe, Southern Hemisphere countries and China.
Maine produces 25% of all lowbush blueberries in North America, making it the largest producer in the world. Maine's 24,291 hectares (60,020 acres) (FAO figures) of blueberry were propagated from native plants that occur naturally in the understory of its coastal forests. The Maine crop requires about 50,000 beehives for pollination, with most of the hives being trucked in from other states for that purpose. Many towns in Maine lay claim to being the blueberry capital, and several festivals are centered around the blueberry. The wild blueberry is the official fruit of Maine and is often as much a symbol of Maine as the lobster. While Maine is the leader of lowbush blueberry production in the United States, Michigan is the leader in highbush production.[7] In 1998, Michigan farms produced 220,000 tonnes (490,000,000 lb) of blueberries, accounting for 32% of the small, round berries eaten in the United States.[8]
Significant acreages of highbush blueberries are cultivated in the states of New Jersey, Florida, Georgia and North Carolina.[9][10]
Canadian exports of blueberries in 2007 were C$323 million, the largest fruit crop produced nationally, occupying more than half of all Canadian fruit acreage.[11] Among the most productive growing regions in the world, British Columbia is the largest Canadian producer of highbush blueberries, yielding 29,000 t (64,000,000 lb) in 2004[12][13] and over C$100 million in 2008 revenues.[11]
Quebec produces a large quantity of wild blueberries, especially in the regions of Saguenay-Lac-Saint-Jean (where a popular name for inhabitants of the regions is bleuets, or "blueberries"), and Côte-Nord which together provide 40% of Quebec's total provincial production. Due in part to declining frequency and intensity of spring frosts, Quebec's wild blueberry production 27,000 t (60,000,000 lb) in 2008[14] now rivals that of Maine, creating cross-border tensions on pricing and regional markets.[15]
Nova Scotia, the biggest producer of wild blueberries in Canada, recognizes the blueberry as its official provincial berry.[16] The town of Oxford is known as the Wild Blueberry Capital of Canada. New Brunswick and Prince Edward Island are other Atlantic provinces with major wild blueberry farming.[17]
Atlantic Canada contributes approximately half of the total North American annual production of 68,000 t (150,000,000 lb), a threefold increase since the 1980s.[18] Gains in yield derived from improved field management, including better weed control, fertility management and irrigation methods, increased use of bees for pollination, and application of mechanical harvesters.
Highbush blueberries were first introduced to Germany and the Netherlands in the 1930s, and have since been spread to [Romania called AFINE], Poland, Italy, Hungary and other countries of Europe.[2]
"Many growers in France, Austria, and Italy realized too that it pays to cultivate highbush blueberries, and that good economic gain can be obtained," according to an industry researcher. "Even in Belgium and Norway, some very promising trials with special methods of blueberry cultivation resulted in a limited commercial production which is very successful. …Except in the United Kingdom, Ireland, and Spain, a blueberry industry is developing in all regions where the production is possible due to the climatic and edaphic conditions…"[2]
The northeastern part of Turkey is one of the main sources of Caucasian whortleberry (V. arctostaphylos), bilberry (V. myrtillus) and bog blueberry, bog whortleberry or bog bilberry (V. uliginosum). Little-known wild blueberries, with various names, such as likapa, ligarba, kaskanaka, çela, morsvi, lifos, çalı çileği, ayı üzümü, and çoban üzümü, grow in this area. This region from Artvin to Kırklareli, as well as parts of Bursa (including Rize, Trabzon, Ordu, Giresun, Samsun, Sinop, and of Kastamonu, Zonguldak, İstanbul, İzmit and Adapazari) has rainy, humid growing periods and natural acidic soils which are suitable for blueberries (Çelik, 2005, 2006 and 2007). Native Vaccinium species and open-pollinated types have been grown for over a hundred years around the Black Sea region of Turkey. These native blueberries are eaten locally as jelly, dried or fresh fruit and also by those in the Black Sea region (Çelik, 2005). These are not cultivated; wild berries grow naturally on the hills, plateaus and forests. On the other hand, highbush blueberry cultivation started around the year 2000. The first commercial blueberry orchard was established by Osman Nuri Yildiz and supervised by Dr. Huseyin Celik, who is the founder of Turkish blueberry cultivation.
In the Southern Hemisphere, Chile, Argentina, Uruguay, South Africa, New Zealand, and Australia now export blueberries.
Blueberries were first introduced to Australia in the 1950s, but the effort was unsuccessful. In the early 1970s, David Jones from the Victorian Department of Agriculture imported seed from the U.S. and a selection trial was started. This work was continued by Ridley Bell, who imported more American varieties. In the mid-1970s, the Australian Blueberry Growers Association was formed. (Clayton-Greene)
By the early 1980s, the blueberry industry was started in New Zealand and is still growing. (BNZ, n.d)
South Africa exports blueberries to Europe.
The industry is even newer in Argentina: "Argentine blueberry production has increased over the last three years with planted area up to 400 percent", according to a 2005 report by the U.S. Department of Agriculture,[19] but that increase comes from a tiny base of 400 hectares (990 acres) in 2001 and 1,600 hectares (4,000 acres) in 2004. The industry is new in the country and farmers are still learning the business. "Argentine blueberry production has thrived in four different regions: the province of Entre Rios in northeastern Argentina, the province of Tucuman, the province of Buenos Aires, near the country’s capital city Buenos Aires, and the southern Patagonian valleys", according to the report.[20]
Chile is the biggest producer in South America and the largest exporter to the Northern Hemisphere, with an estimated area of 6,800 hectares (17,000 acres) (as of 2007). Introduction of the first plants started in the early 1980s and production started in the late 80s in the southern part of the country. Today, production ranges from Copiapó in the north to Puerto Montt in the south, which allows the country to offer blueberries from October through late March. The main production area today is the Biobío Region. Production has evolved rapidly in the last decade, becoming the fourth most important fruit exported in value terms. Fresh market blueberries are exported mainly to North America (80%), followed by Europe (18%). Information from the Fruit Export Association,[21] Chile exported in 2007 more than 21,000 tonnes (46,000,000 lb) of fresh blueberries and more than 1,000 tonnes (2,200,000 lb) of frozen product. Most of the production comes from the highbush type, but several rabbiteye blueberries are grown in the country, as well. Information taken from the Chilean Fruit Producers Federation[22] and their Blueberry Committee, states there are over 800 blueberry producers, with surfaces ranging from 50 to 200 hectares (120 to 490 acres).
The blueberry harvest in North America varies. It can start as early as May and usually ends in late summer. The principle areas of production in the southern hemisphere, Australia Chile, New Zealand and Argentina, begin harvesting in the northern winter and continue until early spring. Similar to other fruits and vegetables, climate-controlled storage allows growers to preserve picked blueberries. This practice can extend the season in which ripe berries can be sold by a month or more.(Gaskell, 2006) Harvest in the UK is June to August.
Blueberries are sold fresh or processed as individually quick frozen (IQF) fruit, purée, juice, or dried or infused berries which in turn may be used in a variety of consumer goods such as jellies, jams, blueberry pies, muffins, snack foods, and cereals.
Blueberry jam is made from blueberries, sugar, water, and fruit pectin. Blueberry wine is made from the flesh and skin of the berry, which is fermented and then matured; usually the lowbush variety is used.[23]
Blueberries have a diverse range of micronutrients, with notably high levels (relative to respective Dietary Reference Intakes) of the essential dietary mineral manganese, vitamin B6, vitamin C, vitamin K and dietary fiber (table).[24] One serving provides a relatively low glycemic load score of 4 out of 100 per day.
| Nutritional value per 100 g (3.5 oz) | |
|---|---|
| Energy | 239 kJ (57 kcal) |
| Carbohydrates | 14.5 g |
| - Dietary fiber | 2.4 g |
| Fat | 0.3 g |
| Protein | 0.7 g |
| Vitamin A | 54 IU |
| - lutein and zeaxanthin | 80 μg |
| Thiamine (vit. B1) | 0.04 mg (3%) |
| Riboflavin (vit. B2) | 0.04 mg (3%) |
| Niacin (vit. B3) | 0.42 mg (3%) |
| Pantothenic acid (B5) | 0.1 mg (2%) |
| Vitamin B6 | 0.1 mg (8%) |
| Folate (vit. B9) | 6 μg (2%) |
| Vitamin C | 10 mg (12%) |
| Vitamin E | 0.6 mg (4%) |
| Vitamin K | 19 μg (18%) |
| Calcium | 6 mg (1%) |
| Iron | 0.3 mg (2%) |
| Magnesium | 6 mg (2%) |
| Manganese | 0.3 mg (14%) |
| Phosphorus | 12 mg (2%) |
| Potassium | 77 mg (2%) |
| Zinc | 0.2 mg (2%) |
| Percentages are relative to US recommendations for adults. Source: USDA Nutrient Database |
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Especially in wild species, blueberries contain anthocyanins, other antioxidant pigments and various phytochemicals, which possibly have a role in reducing risks of some diseases,[25] including inflammation and certain cancers.[26][27][28]
Researchers have shown blueberries contain pterostilbene, anthocyanins, proanthocyanidins, resveratrol, flavonols, and tannins, which inhibit mechanisms of cancer cell development and inflammation in vitro.[29][30][31][32] Similar to red grape, some blueberry species contain in their skins significant levels of resveratrol,[33] a phytochemical.
Although most studies below were conducted using the highbush cultivar of blueberries (V. corymbosum), content of polyphenol antioxidants and anthocyanins in lowbush (wild) blueberries (V. angustifolium) exceeds values found in highbush species.[34]
At a 2007 symposium on berry health benefits, reports showed consumption of blueberries (and similar berry fruits including cranberries) may alleviate the cognitive decline occurring in Alzheimer's disease and other conditions of aging.[25]
Proanthocyanidin, a chemical isolated from blueberry leaves, can block replication of the hepatitis C virus and might help to delay disease spread in infected individuals if ingested as a dietary supplement at a dosage 1/100th of the toxic threshold.[35]
Feeding blueberries to animals lowers brain damage in experimental stroke.[36][37] Research at Rutgers[38] has also shown that blueberries may help prevent urinary tract infections.
Dr. Arpita Basu, an assistant professor of nutrition at Oklahoma State University, showed in several laboratory-based animal and cell studies that anthocyanins, found in blueberries, cause blood vessels to relax and increase production of nitric oxide that helps in maintaining normal blood pressure.[39]
Other animal studies found blueberry consumption lowered cholesterol and total blood lipid levels, possibly affecting symptoms of heart disease.[40] Additional research showed that blueberry consumption in rats altered glycosaminoglycans which are vascular cell components affecting control of blood pressure.[41]
A study soon to be published in the Journal of Agricultural and Food Chemistry found supplementation of diets with wild blueberry juice enhanced memory and learning in older adults, while reducing blood sugar and symptoms of depression.[42]
In June 2011 the Environmental Working Group rated pesticides in blueberries a significant concern, based on the most recent 2009 USDA laboratory test data.[43][44] Domestic US blueberries were scored at number 10 in the "Dirty Dozen"; imported were better, 23 out of 53 rated fruits and vegetables. (BLUEBERRIES - 52 Pesticide Residues) (BLUEBERRIES, FROZEN - 21 Pesticide Residues)
Because "wild" is a marketing term generally used for all low-bush blueberries, it is no guarantee that pesticides have not been used. For example, the application of pesticides is common in large-scale blueberry monoculture in Maine.[45]