Brazil nut

In Portuguese-speaking countries, like Brazil, they are variously called "" (meaning "chestnut from Brazil" in Portuguese), "" (meaning "chestnut from Pará" in Portuguese), castanha-da-amazônia, castanha-do-acre, "" (meaning "Amazonian nut" in Portuguese), noz boliviana, tocari (probably of Carib origin), and tururi (from Tupi ''turu'ri''). In North America, as early as 1896, Brazil nuts were sometimes known by the slang term "nigger toes", a vulgarity that fell out of use after the racial slur became more socially unacceptable. == Description ==

Supplement'', No. 598, June 18, 1887 The Brazil nut is a large tree, reaching tall, with a trunk in diameter, making it among the largest of trees in the Amazon rainforest. It may live for 500 years or more, and can often reach a thousand years of age. 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, long, and broad. The flowers are small, greenish-white, in panicles 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-bodied bees of the genera Bombus, Centris, Epicharis, Eulaema, and Xylocopa, which are the only ones capable of pollinating the tree's flowers, with different bee genera being the primary pollinators in different areas, and different times of year. Brazil nuts have been harvested from plantations, but production is low and is currently not economically viable. The fruit takes 14 months to mature after pollination of the flowers. The fruit itself is a large capsule in diameter, resembling a coconut endocarp in size and weighing up to . It has a hard, woody shell thick, which contains eight to 24 wedge-shaped seeds long (the "Brazil nuts") packed like the segments of an orange, but not limited to one whorl of segments. Up to three whorls can be stacked onto each other, with the polar ends of the segments of the middle whorl nestling into the upper and lower whorls (see illustration above). 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 seeds 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 caches during wet season, and the young saplings may have to wait years, in a state of dormancy, for a tree to fall and sunlight to reach it, when it starts growing again. == Taxonomy ==

The Brazil nut family, the Lecythidaceae, is in the order Ericales, as are other well-known plants such as blueberries, cranberries, sapote, gutta-percha, tea, phlox, and persimmons. The tree is the only species in the monotypic genus Bertholletia, ==Distribution and habitat==

The Brazil nut 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 River, Rio Negro, Tapajós, and the Orinoco. The fruit is heavy and rigid; when the fruits fall, they pose a serious threat to vehicles and potential for traumatic brain injury of people passing under the tree. ==Ecology==

Capuchin monkeys have been reported to open Brazil nuts using a stone as an anvil. ==Production==

In 2023, world production of Brazil nuts (in shells) was 75,910 tonnes, most of which derive from wild harvests in tropical forests, especially the Amazon regions of Brazil and Bolivia which together produced 91% of the total (table). Environmental effects of harvesting Since most of the production for international trade is harvested in the wild, the business arrangement has been advanced as a model for generating income from a tropical forest without destroying it. ==Toxicity==

Brazil nuts are susceptible to contamination by aflatoxins, produced by fungi, once they fall to the ground. Aflatoxins can cause liver damage, including possible cancer, if consumed. The nuts may contain traces of radium, a radioactive element, with a kilogram of nuts containing an activity between . This level of radium is small, although higher than in other common foods. According to Oak Ridge Associated Universities, elevated levels of radium in the soil do not directly cause the concentration of radium, but "the very extensive root system of the tree" can concentrate naturally occurring radioactive material, when present in the soil. Radium can be concentrated in nuts only if it is present in the soil. Brazil nuts also contain barium, a metal with a chemical behavior quite similar to radium. While barium can have toxic side effects when ingested (weakness, vomiting, diarrhea, etc.) the amount present in Brazil nuts is too small to have noticeable health effects. ==Uses==

Nutrition Brazil nuts are 3% water, 14% protein, 12% carbohydrates, and 66% fats. The fat components are 16% saturated, 24% monounsaturated, and 24% polyunsaturated. In a reference amount, Brazil nuts supply 659 calories, and are a rich source (20% or more of the Daily Value, DV) of dietary fiber (30% DV), thiamin (54% DV), vitamin E (38% DV), magnesium (106% DV), phosphorus (104% DV), manganese (57% DV), and zinc (43% DV). Calcium, iron, and potassium are present in moderate amounts (10–19% DV). Selenium Brazil nuts are a particularly rich source of selenium, with just supplying 544 micrograms of selenium or 10 times the DV of 55 micrograms. However, the amount of selenium within batches of nuts may vary considerably. The high selenium content is used as a biomarker in studies of selenium intake and deficiency. Consumption of just one Brazil nut per day over 8 weeks was sufficient to restore selenium blood levels and increase HDL cholesterol in obese women. and fat-soluble vitamin E. The following table presents the composition of fatty acids in Brazil nut oil: Logging the trees is prohibited by law in all three producing countries (Brazil, Bolivia, and Peru). Illegal extraction of timber and land clearances present continuing threats. In Brazil, cutting down a Brazil nut tree requires previous authorization from the Brazilian Institute of Environment and Renewable Natural Resources. Other uses Brazil nut oil is used as a lubricant in clocks and in the manufacturing of paint and cosmetics, such as soap and perfume. Because of its hardness, the Brazil nutshell is often pulverized and used as an abrasive to polish materials, such as metals and ceramics, in the same way as jeweler's rouge, while charcoal from the shells can be used to purify water. ==See also==