Brazil nut

From Wikipedia, the free encyclopedia - View original article

Brazil Nut Tree
Conservation status
Scientific classification
Kingdom:Plantae
(unranked):Angiosperms
(unranked):Eudicots
(unranked):Asterids
Order:Ericales
Family:Lecythidaceae
Genus:Bertholletia
Species:B. excelsa
Binomial name
Bertholletia excelsa
Humb. & Bonpl.
 
Jump to: navigation, search
Brazil Nut Tree
Conservation status
Scientific classification
Kingdom:Plantae
(unranked):Angiosperms
(unranked):Eudicots
(unranked):Asterids
Order:Ericales
Family:Lecythidaceae
Genus:Bertholletia
Species:B. excelsa
Binomial name
Bertholletia excelsa
Humb. & Bonpl.

The Brazil nut (Bertholletia excelsa) is a South American tree in the family Lecythidaceae, and also the name of the tree's commercially harvested edible seed.

Contents

Order

The Brazil nut family is in the order Ericales, as are other well known plants such as: blueberries, cranberries, sapote, gutta-percha, tea, kiwi fruit, phlox, and persimmons.

Brazil nut tree

The Brazil nut tree is the only species in the monotypic type genus Bertholletia. It is native to the Guianas, Venezuela, Brazil, eastern Colombia, eastern Peru and eastern Bolivia. It occurs as scattered trees in large forests on the banks of the Amazon, Rio Negro, Tapajós, and the Orinoco. The genus is named after the French chemist Claude Louis Berthollet.

The Brazil nut is a large tree, reaching 50 metres (160 ft) tall and 1 to 2 metres (3.3 to 6.6 ft) in diameter, making it among the largest of trees in the Amazon Rainforests. It may live for 500 years or more, and according to some authorities often reaches an age of 1,000 years.[1] The stem is straight and commonly without branches for well over half the tree's height, with a large emergent crown of long branches above the surrounding canopy of other trees.

The bark is grayish and smooth. The leaves are dry-season deciduous, alternate, simple, entire or crenate, oblong, 20–35 centimetres (7.9–14 in) long and 10–15 centimetres (3.9–5.9 in) broad. The flowers are small, greenish-white, in panicles 5–10 centimetres (2.0–3.9 in) long; each flower has a two-parted, deciduous calyx, six unequal cream-colored petals, and numerous stamens united into a broad, hood-shaped mass.

Reproduction

Brazil nut trees produce fruit almost exclusively in pristine forests, as disturbed forests lack the large-body bees of the genera Bombus, Centris, Epicharis, Eulaema, and Xylocopa which are the only ones capable of pollinating the tree's flowers.[2][3] Brazil nuts have been harvested from plantations but production is low and it is currently not economically viable.[4][5][6]

A freshly cut Brazil nut fruit

The Brazil nut tree's yellow flowers contain very sweet nectar and can only be pollinated by an insect strong enough to lift the coiled hood on the flower and with a tongue long enough to negotiate the complex coiled flower. For this reason, the Brazil nut's reproduction depends on the presence of the orchid Coryanthes vasquezii,[7] which does not grow on the Brazil nut tree itself.[8] The orchids produce a scent that attracts small male long-tongued orchid bees (Euglossa spp), as the male bees need that scent to attract females. The large female long-tongued orchid bee pollinates the Brazil nut tree. Without the orchid, the bees do not mate, and therefore the lack of bees means the fruit does not get pollinated.

The fruit takes 14 months to mature after pollination of the flowers. The fruit itself is a large capsule 10–15 centimetres (3.9–5.9 in) in diameter, resembling a coconut endocarp in size and weighing up to 2 kilograms (4.4 lb). It has a hard, woody shell 8–12 millimetres (0.31–0.47 in) thick, which contains 8–24 triangular seeds 4–5 centimetres (1.6–2.0 in) long (the "Brazil nuts") packed like the segments of an orange.

The capsule contains a small hole at one end, which enables large rodents like the Agouti to gnaw it open. They then eat some of the nuts inside while burying others for later use; some of these are able to germinate into new Brazil nut trees. Most of the seeds are "planted" by the Agoutis in shady places, and the young saplings may have to wait years, in a state of dormancy, for a tree to fall and sunlight to reach it. It is not until then that it starts growing again. Capuchin monkeys have been reported to open Brazil nuts using a stone as an anvil.

Nomenclature

Brazil nut seeds
Depiction of the Brazil nut in Scientific American Supplement, No. 598, June 18, 1887

Despite their name, the most significant exporter of Brazil nuts is not Brazil but Bolivia, where they are called almendras. In Brazil these nuts are called castanhas-do-Pará (literally "nuts from Pará"), but Acreans call them castanhas-do-Acre instead. Indigenous names include juvia in the Orinoco area, and sapucaia in the rest of Brazil.

Though it is commonly called the Brazil nut, in botanical terms it is the seed from the fruit of this tree; a nut is a hard-shelled indehiscent fruit.

Brazil nuts are sometimes known by the term "nigger toes".[9] They can be seen being sold in a market under this name in a scene from the 1922 Stan Laurel film The Pest.

Nut production

Around 20,000 tons of Brazil nuts are harvested each year, of which Bolivia accounts for about 50%, Brazil 40% and Peru 10% (2000 estimates).[10] In 1980, annual production was around 40,000 tons per year from Brazil alone, and in 1970 Brazil harvested a reported 104,487 tons of nuts.[4]

Effects of harvesting

Brazil nuts for international trade come entirely[citation needed] from wild collection rather than from plantations. This has been advanced as a model for generating income from a tropical forest without destroying it. The nuts are gathered by migrant workers known as castanheiros.

Analysis of tree ages in areas that are harvested show that moderate and intense gathering takes so many seeds that not enough are left to replace older trees as they die. Sites with light gathering activities had many young trees, while sites with intense gathering practices had hardly any young trees.[11]

Statistical tests were done to determine what environmental factors could be contributing to the lack of younger trees. The most consistent effect was found to be the level of gathering activity at a particular site. A computer model predicting the size of trees where people picked all the nuts matched the tree size data that was gathered from physical sites that had heavy harvesting.

Uses

Nutrition

Brazil nuts after shell removal
Nuts, brazilnuts, dried, unblanched, shelled
Nutritional value per 100 g (3.5 oz)
Energy2,743 kJ (656 kcal)
Carbohydrates12.27 g
- Starch0.25 g
- Sugars2.33 g
- Dietary fiber7.5 g
Fat66.43 g
- saturated15.137 g
- monounsaturated24.548 g
- polyunsaturated20.577 g
Protein14.32 g
- Tryptophan0.141 g
- Threonine0.362 g
- Isoleucine0.516 g
- Leucine1.155 g
- Lysine0.492 g
- Methionine1.008 g
- Cystine0.367 g
- Phenylalanine0.630 g
- Tyrosine0.420 g
- Valine0.756 g
- Arginine2.148 g
- Histidine0.386 g
- Alanine0.577 g
- Aspartic acid1.346 g
- Glutamic acid3.147 g
- Glycine0.718 g
- Proline0.657 g
- Serine0.683 g
Water3.48 g
Thiamine (vit. B1)0.617 mg (54%)
Riboflavin (vit. B2)0.035 mg (3%)
Niacin (vit. B3)0.295 mg (2%)
Vitamin B60.101 mg (8%)
Folate (vit. B9)22 μg (6%)
Vitamin C0.7 mg (1%)
Vitamin E5.73 mg (38%)
Calcium160 mg (16%)
Iron2.43 mg (19%)
Magnesium376 mg (106%)
Manganese1.223 mg (58%)
Phosphorus725 mg (104%)
Potassium659 mg (14%)
Sodium3 mg (0%)
Zinc4.06 mg (43%)
Percentages are relative to
US recommendations for adults.
Source: USDA Nutrient Database

Brazil nuts are 18% protein, 13% carbohydrates, and 69% fat by weight, and 91% of their calories come from fat. The fat breakdown is roughly 25% saturated, 41% monounsaturated, and 34% polyunsaturated.[12] Due to their high polyunsaturated fat content, primarily omega-6 fatty acids, shelled Brazil nuts soon become rancid.

Nutritionally, Brazil nuts are a good source of some vitamins and minerals. A cup (133 grams) of Brazil nuts contains the vitamins thiamin (0.8 mg—55% DV) and vitamin E (7.6 mg—38% DV); minerals calcium (213 mg—21% DV), magnesium (500 mg—125% DV), phosphorus (946 mg—96% DV), copper (2.3 mg—116% DV), and manganese (1.6 mg—81%).[13] Brazil nuts are perhaps the richest dietary source of selenium; 28 g (1 oz, 6–8 nuts) can contain as much as 544 µg.[14] This is 10 times the adult U.S. Recommended Dietary Allowances, more even than the Tolerable Upper Intake Level (UL), although the amount of selenium within batches of nuts varies greatly.[15]

Recent research suggests that proper selenium intake is correlated with a reduced risk of both breast cancer and prostate cancer.[16] This has led some health commentators and nutritionists to recommend the consumption of Brazil nuts as a protective measure.[17][18] These findings are inconclusive, however; other investigations into the effects of selenium on prostate cancer were inconclusive.[19]

Brazil nuts have one of the highest concentrations of phytic acid at 2 to 6% of dry weight. Phytic acid can prevent absorption of some nutrients, mainly iron, but is also a subject of research and possibly confers health benefits.

Despite the possible health benefits of the nut, the European Union has imposed strict regulations on the import from Brazil of Brazil nuts in their shells, as the shells have been found to contain high levels of aflatoxins, which can lead to liver cancer.[20]

Brazil nuts contain small amounts of radium. Although the amount of radium, a radioactive element, is very small, about 1–7 pCi/g (40–260 Bq/kg), and most of it is not retained by the body, this is 1,000 times higher than in other foods. According to Oak Ridge Associated Universities, this is not because of elevated levels of radium in the soil, but due to "the very extensive root system of the tree."[21]

Other uses

A carved Brazil nut fruit

As well as its food use, Brazil nut oil is also used as a lubricant in clocks, for making artists' paints, and in the cosmetics industry.

The lumber from Brazil nut trees (not to be confused with Brazilwood) is of excellent quality, but logging the trees is prohibited by law in all three producing countries (Brazil, Bolivia and Peru). Illegal extraction of timber and land clearances present a continuing threat.[22]

See also

References

  1. ^ Bruno Taitson (January 18, 2007). "Harvesting nuts, improving lives in Brazil". World Wildlife Fund. Archived from the original on May 23, 2008. http://web.archive.org/web/20080523200535/http://www.assets.wwf.no/news_facts/newsroom/features/index.cfm?uNewsID=92320. Retrieved July 17, 2012.
  2. ^ Nelson, B.W.; Absy, M.L.; Barbosa, E.M.; Prance, G.T. (1985). "Observations on flower visitors to Bertholletia excelsa H. B. K. and Couratari tenuicarpa A. C. Sm.(Lecythidaceae).". Acta Amazonica 15 (1): 225–234. http://www.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=1566670. Retrieved 2008-04-08.
  3. ^ Moritz, A. (1984). Estudos biológicos da floração e da frutificação da castanha-do-Brasil (Bertholletia excelsa HBK). 29. http://orton.catie.ac.cr/cgi-bin/wxis.exe/?IsisScript=ACERVO.xis&method=post&formato=2&cantidad=1&expresion=mfn=029738. Retrieved 2008-04-08.
  4. ^ a b Scott A. Mori. "The Brazil Nut Industry --- Past, Present, and Future". The New York Botanical Garden. http://www.nybg.org/bsci/braznut. Retrieved July 17, 2012.
  5. ^ Tim Hennessey (March 2, 2001). "The Brazil Nut (Bertholletia excelsa)". Archived from the original on January 11, 2009. http://web.archive.org/web/20090111010933/http://www.siu.edu/~ebl/leaflets/brazil.htm. Retrieved July 17, 2012.
  6. ^ Enrique G. Ortiz. "The Brazil Nut Tree: More than just nuts". Archived from the original on July 6, 2007. http://web.archive.org/web/20080216221836/http://www.bertholletia.org/bertholletia/benefits/benefits.html. Retrieved July 17, 2012.
  7. ^ "Coryanthes vasquezii". Orchid Web. http://www.orchidweb.com/OrchidOfWeek.aspx?id=1125. Retrieved July 17, 2012.
  8. ^ Lingis, Alphonso (2000). Dangerous Emotions. University of California Press. p. 26. ISBN 978-0-520-22559-6. http://books.google.com/?id=l6waj7fjApYC&pg=PA26. Retrieved 2009-04-08.
  9. ^ Brazil, Matt (July 14, 2000). "Actually, My Hair Isn't Red". The Wall Street Journal (Dow Jones & Company, Inc.). http://online.wsj.com/article/SB963525645774992420.html?mod=googlewsj. Retrieved 2009-07-06. "Hearing angmo so often took me back to my childhood, when my friends and I used the words Jew and Gyp (the latter short for Gypsy) as verbs, meaning to cheat. At that time, in the 1960s, other racial epithets, these based on physical appearance, were commonly heard: cracker, slant-eye, bongo lips, knit-head. To digress to the ludicrous, Brazil nuts were called "nigger toes.""
  10. ^ Chris Collinson; Duncan Burnett, Victor Agreda (Spring 2000). "Economic Viability of Brazil Nut Trading in Peru". Natural Resources Institute, University of Greenwich. http://www.nri.org/projects/nret/brazilnuts.pdf. Retrieved July 17, 2012.
  11. ^ Silvertown, J. (2004). "Sustainability in a nutshell". Trends in Ecology & Evolution 19 (6): 276–201. doi:10.1016/j.tree.2004.03.022. edit
  12. ^ "Nuts, brazilnuts, dried, unblanched". United States Department of Agriculture. http://www.nal.usda.gov/fnic/foodcomp/Data/SR21/reports/sr21fg12.pdf. Retrieved July 17, 2012.
  13. ^ "Nutrition Data, Brazil Nuts 1 cup". NutritionData. http://nutritiondata.self.com/facts/nut-and-seed-products/3091/2. Retrieved July 17, 2012.
  14. ^ "Nuts, brazilnuts, dried, unblanched". USDA National Nutrient Database for Standard Reference, Release 25: Selenium, Se ( µg ) Content of Selected Foods per Common Measure. United States Department of Agriculture. p. 17. https://www.ars.usda.gov/SP2UserFiles/Place/12354500/Data/SR25/nutrlist/sr25a317.pdf. Retrieved November 6, 2012.
  15. ^ Chang, Jacqueline C.; Walter H. Gutenmann, Charlotte M. Reid, Donald J. Lisk (1995). "Selenium content of Brazil nuts from two geographic locations in Brazil". Chemosphere 30 (4): 801–802. doi:10.1016/0045-6535(94)00409-N. PMID 7889353. 0045-6535.
  16. ^ Klein, EA; Thompson, IM; Lippman, SM; Goodman, PJ; Albanes, D; Taylor, PR; Coltman, C (October 2001). "SELECT: the next prostate cancer prevention trial. Selenum and Vitamin E Cancer Prevention Trial.". The Journal of Urology 166 (4): 1311-1315. ISSN 0022-5347. PMID 11547064.
  17. ^ Ralph W. Moss (December 10, 2001). "Selenium, Brazil Nuts and Prostate Cancer". CancerDecisions Newsletter Archive. CancerDecisions. Archived from the original on September 18, 2010. http://web.archive.org/web/20100918203630/http://cancerdecisions.com/121001.html. Retrieved July 17, 2012.
  18. ^ Ann Kulze (October 30, 2009). "Dr. Ann's 10-Steps to Prevent Breast Cancer". About.com. http://womenshealth.about.com/od/cancerprevention/a/10stepsprevbcan.htm. Retrieved July 17, 2012.
  19. ^ Peters, U; Foster, CB; Chatterjee, N; Schatzkin, A; Reding, D; Andriole, GL; Crawford, ED; Sturup, S; Chanock, SJ; Hayes, RB (January 2007). "Serum selenium and risk of prostate cancer-a nested case-control study.". The American journal of clinical nutrition 85 (1): 209-17. PMC 1839923. PMID 17209198. http://www.ajcn.org/content/85/1/209.full.pdf. Retrieved July 17, 2012.
  20. ^ "Commission Decision of 4 July 2003 imposing special conditions on the import of Brazil nuts in shell originating in or consigned from Brazil". Official Journal of the European Union. July 5, 2012. http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2003:168:0033:0038:EN:PDF. Retrieved July 17, 2012.
  21. ^ "Brazil Nuts". Oak Ridge Associated Universities. January 20, 2009. http://www.orau.org/PTP/collection/consumer%20products/brazilnuts.htm. Retrieved July 17, 2012.
  22. ^ "Greenpeace Activists Trapped by Loggers in Amazon". Greenpeace. October 18, 2007. http://www.greenpeace.org/international/en/news/features/activists-trapped-by-loggers071018/. Retrieved July 17, 2012.

External links