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Blueberries are a group of flowering plants in the genus Vaccinium, sect. Cyanococcus. The species are native to North America and eastern Asia. They are shrubs varying in size from 10 cm tall to 4 m tall; the smaller species are known as "lowbush blueberries", and the larger species as "highbush blueberries". The leaves can be either deciduous or evergreen, ovate to lanceolate, and from 1-8 cm long and 0.5-3.5 cm broad. The flowers are bell-shaped, white, pale pink or red, sometimes tinged greenish.
The fruit is a berry 5-16 mm diameter with a flared "crown" at the end; they are pale greenish at first, then reddish-purple, and finally turn blue or dark purple on ripening. They have a sweet taste when mature, with variable acidity. The blueberry season typically runs from May to October, peaking in July.
All the species whose common names in English include "blueberry" are currently classified in section Cyanococcus of the genus Vaccinium. Other sections in the genus, native to other parts of the world including Europe, include other wild shrubs producing edible berries such as cranberries, bilberries and cowberries. Many of these have blue berries and are very similar in use and taste to blueberries. Furthermore their names in languages other than English often translate as "blueberry", e.g. Scots Blaeberry and Norwegian Blåbær. There is thus considerable scope for confusion. This page, however, deals only with the plants called "blueberry" in English, i.e. section Cyanococcus of the genus.
Although blueberries are native to North America, they are now grown also in Australia, New Zealand and South American countries[1], and are air-shipped as fresh produce to markets around the world. Blueberries are one of the only human foods naturally colored blue.
- Species
- Vaccinium angustifolium (Lowbush Blueberry)
- Vaccinium boreale (northern blueberry)
- Vaccinium caesariense (New Jersey blueberry)
- Vaccinium corymbosum (Northern Highbush Blueberry)
- Vaccinium darrowii (Southern Highbush Blueberry)
- Vaccinium elliottii (Elliot Blueberry)
- Vaccinium formosum (southern blueberry)
- Vaccinium fuscatum (Black Highbush Blueberry; syn. V. atrococcum)
- Vaccinium hirsutum (Hairy-fruited Blueberry)
- Vaccinium koreanum
- Vaccinium myrsinites (Evergreen Blueberry)
- Vaccinium myrtilloides (Canadian Blueberry)
- Vaccinium pallidum (Dryland Blueberry)
- Vaccinium simulatum (upland highbush blueberry)
- Vaccinium tenellum (Southern Blueberry)
- Vaccinium virgatum (Rabbiteye Blueberry; syn. V. ashei)
Cultivation
Blueberries are both cultivated and picked wild. 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.
Wild blueberries, smaller and much more expensive than cultivated ones, are prized for their intense flavour and color. The Lowbush Blueberry, V. angustifolium, is found from Newfoundland westward and southward to Michigan and West Virginia. In some areas it produces natural blueberry barrens, where it is practically the only species covering large areas. Several First Nations communities in Ontario are involved in harvesting wild blueberries. Low bush 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.
There are numerous highbush cultivars of blueberries, each of which have a unique and diverse flavour. One of the first "wild" cultivars of blueberries is the 'Rubel'. During the Great Depression, farmers were offered $20 for the best wild blueberry bushes they could find. 'Rubel' is one such wild blueberry cultivar and is the origin of many of the current hybrid cultivars.
Rabbiteye Blueberry (V. virgatum) 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., but common in the Appalachians and the Piedmont of the Southeast. Sparkleberry, V. arboreum, is a common wild species on sandy soils in the southeastern U.S. Its fruit are important to wildlife, and the flowers important to beekeepers.
Growing areas
Maine produces 25% of all blueberries in North America, making it the largest producer in the world. Maine's 24,291 hectares (FAO figures) [60,023 acres] of blueberry were propagated from native plants that occur naturally in the understorey 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.
Quebec has largest quantity of wild blueberry production, coming especially from the regions of Saguenay-Lac-Saint-Jean and Côte-Nord Which is 40% of Quebec blueberries provincial production. Quebec were also producing an additionnal of 18 717 hectares in farms in 2001 and now increasing this number by 10 000 hectares.
Michigan, New York, New Jersey and North Carolina are large producers of Highbush Blueberries.
Oregon, Washington and British Columbia are becoming major producers of blueberries. California is rapidly increasing plantings largely through the cultivation of Southern Highbush varieties originating largely from the University of Florida. Southern Highbush is now also cultivated in the Mediterranean regions of Europe.
Nova Scotia is also a producer of blueberries, which grow naturally in the Province. The town of Oxford, Nova Scotia is known as the Wild Blueberry Capital of Canada. The blueberry is also the Provincial Berry of the Province of Nova Scotia.
Highbush blueberries were first introduced to Germany and the Netherlands in the 1930s and have since spread to Poland and elsewhere on the continent.(Nauman, 1993)
"[M]any growers in France, Austria, and Italy realised 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 ..." (Nauman, 1993).
In the Southern hemisphere, Chile, Argentina, New Zealand, and Australia now export blueberries. South Africa exports them to Europe.
Blueberries were first introduced to Australia in the 1950s, but the effort was unsuccessful. "In the early 1970's 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 (ABGA) was formed. (Clayton-Greene)
By the early 1980s, the blueberry industry was started in New Zealand and is still growing.(BNZ, n.d)
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. But that increase comes from a tiny base of 400 hectares in 2001 (to 1,600 hectares in 2004). The industry is new in the country and farmers are still learning the business. "Argentine blueberry production has thrived in three different regions: the province of Entre Rios in Northeastern Argentina, the province of Buenos Aires, near the country’s capital city Buenos Aires, and the southern Patagonian valleys," according to the report.(Gain, 2005)
Growing seasons
Blueberry production in North America typically starts in mid-May (in Florida) and ends in September, when some fruit is held over in controlled-atmosphere storage in Oregon, Washington and Canada.(Gaskell, 2006).
Sources give different periods for the growing season in the southern hemisphere. According to the University of California Extension Service, Chile, New Zealand and Argentina begin harvesting in the winter and continue till mid-March, when Chilean blueberries are held over in controlled-atmosphere storage for about six weeks. "As a result, blueberries reach annual peak prices in mid-April."(Gaskell, 2006)
In Chile, San Jose Farms, which says (according to its Web site) that it is one of the oldest blueberry producers in the country (it started in the early 1990s), states that its harvest season starts in November and continues through March. (San Jose, n.d.)
In Argentina: "The marketing year (MY) for blueberries begins in September and ends in February," according to a U.S. Department of Agriculture report. (Gain, 2005)
Uses
Blueberries are used in jellies, jams, and pies, baked into muffins, and are an ingredient of many other snacks and delicacies. Some baked products incorporate artificial blueberries.
Blueberry jam is a jam made out of blueberries, sugar and water, and fruit pectin. Commercial jams often contain preservatives such as citric acid. Premium artisanal blueberry jam is produced in Canada and the United States from wild blueberries, which are smaller and more difficult to harvest but more intensely flavoured than cultivated blueberries. Most production is in Maine, northwestern Ontario, and in the Saguenay-Lac-Saint-Jean region of Quebec.
In the last few years, blueberry juice has entered the market and is now considered a whole new category of juice in the beverage aisle. The last new juice category that was successfully introduced was cranberry juice, over 60 years ago. Blueberry juice brands include TrueBlue, POM, and R.W. Knudsen Family.
Health
Blueberries, especially wild species, contain antioxidants which have been found to reduce the risks of some cancers. Researchers in Prince Edward Island have shown that the tannins in blueberries are very active at lowering a protein involved in metastasis of cancer, at least in isolated cells (Matchett and others, 2005). At the 2004 International Conference on Longevity, a group of researchers released details of a study that suggests certain compounds found in blueberries (and some similar fruits, including cranberries) have a significant impact in reducing the degradation of brain function, as in Alzheimer's Disease and other conditions ([2], [3]). Feeding blueberries to animals lowers stroke damage (Sweeney). Research at Rutgers http://aesop.rutgers.edu/~bluecran/medicinalgeneralinfopage.htm] has also shown that blueberries may help prevent urinary tract infections. Additional studies also found that blueberries were better at lowering cholesterol and lipid levels in the blood, which help alleviate and even reverse signs and symptoms of heart disease. Ciprofibrate was found to be inferior to the blueberries in lowering cholesterol. The signs point to pterostilbene, which signal cells to break down lipids and cholesterol.[4] All of these studies were conducted using high bush, hybrid cultivars of blueberries. A more recent study Template:Fact has tentatively found that anti-oxidants may be higher in lowbush blueberries than in highbush blueberries. The study is flawed in that it does not specify which of the many unique and diverse cultivars of high bush blueberries were used for the comparison or even where the blueberries were grown. The soil where the blueberries were grown impacts the composition of the minerals present.
140 grams of fresh blueberries contain 3 g of fibre [5]. Additionally blueberries are high in manganese (Mn) as well as vitamin k and have a very low glycemic load (3) in a single 155g serving, making it an ideal food for diabetics. [6]
References
- BNZ, n.d: "Blueberries New Zealand Inc" Web page[7] at the site of the organization of the same name, accessed August 24, 2006.
- Clayton-Greene, K.: Web page titled "THE BLUEBERRY INDUSTRY IN AUSTRALIA: AN OVERVIEW" a summary of an article[8] at the Web site for the International Society for Horticultural Science. The article appears to have been written in the 1990s, accessed August 24, 2006.
- Gain, 2005: "USDA Foreign Agricultural Service: GAIN Report: Global Agriculture Information Network"[9], January 12, 2005, accessed August 24, 2006</ref>
- Gaskell, Mark. "Strategies for Off-Season Blueberry Production on Coastal California Small Farms," an article[10] in "Central Coast Agriculture Highlights" a newsletter published by the University of California Cooperative Extension, February 2006 issue, page 2, accessed August 24, 2006.
- Nauman, W.D. Web page[11] titled "OVERVIEW OF THE VACCINIUM INDUSTRY IN WESTERN EUROPE," a summary of an article by W.D. Naumann presented at the Fifth International Symposium on Vaccinium Culture and published in July 1993, from the Web site of the International Society for Horticultural Science, accessed August 24, 2006.
- San Jose, n.d.: San Jose Farms Web site, "Products: Blueberries" Web page[12], accessed August 24, 2006</ref>
- Sweeney M.I., Kalt W., MacKinnon S.L., Ashby J. and Gottschall-Pass K.T. Feeding of diets enriched in lowbush blueberries (Vaccinium angustifolium) for six weeks decreases stroke severity in rats. Nutritional Neuroscience 5: 427-431, 2002.
- Matchett, M.D., MacKinnon, S.L., Sweeney, M.I., Gottschall-Pass, K.T., and Hurta, R.A.R. Blueberry flavonoids inhibit matrix metalloproteinase activity in DU145 human prostate cancer cells. Biochem Cell Biol. 83: 637-643, 2005.
- University of California Cooperative Extension (2006). Strategies for Off-Season Blueberry Production on Coastal California Small Farms (pdf file) an article by Mark Gaskell in Central Coast Agriculture Highlights newsletter. Accessed August 24 2006.
- Joseph, J.A., Shukitt-Hale B., Denisova, N.A. Bielinksi D., Martin, A., McEwen, J.J., & Bickford, P.C., 1999. Reversals of age-related declines in neuronal signal transduction, cognitive, and motor behavioral deficits with blueberry, spinach, or strawberry dietary supplementation. Journal of Neuroscience 19 (18): 8114–8121.
- Sumner, Judith (2004). American Household Botany: A History of Useful Plants, 1620-1900. Timber Press. pp. 125. ISBN 0-88192-652-3. Google books link
- Wild blueberry culture in Maine (FAO)
- "The Blueberry Bulletin" newsletter (New Jersey)
- Industry associations