Brazil nut
The Brazil nut (Bertholletia excelsa) is a South American tree in the family Lecythidaceae, and it is also the name of the tree's commercially harvested edible seeds.[2] It is one of the largest and longest-lived trees in the Amazon rainforest. The fruit and its nutshell – containing the edible Brazil nut – are relatively large, possibly weighing as much as 2 kg (4.4 lb) in total weight. As food, Brazil nuts are notable for diverse content of micronutrients, especially a high amount of selenium. The wood of the Brazil nut tree is prized for its quality in carpentry, flooring, and heavy construction.
Not to be confused with the brazilwood tree.Common names[edit]
In Portuguese-speaking countries, like Brazil, they are variously called "castanha-do-brasil"[3][4] (meaning "chestnuts from Brazil" in Portuguese), "castanha-do-pará" (meaning "chestnuts from Pará" in Portuguese), with other names: castanha-da-amazônia,[5] castanha-do-acre,[6] "noz amazônica" (meaning "Amazonian nut" in Portuguese), noz boliviana, tocari ("probably of Carib origin"[7]), and tururi (from Tupi turu'ri[8]) also used.[2]
In various Spanish-speaking countries of South America, Brazil nuts are called castañas de Brasil, nuez de Brasil, or castañas de Pará (or Para).[2][9]
In North America, as early as 1896, Brazil nuts were sometimes known by the slang term "nigger toes",[10][11][12] a vulgarity that fell out of use after the racial slur became socially unacceptable.[13][14]
Taxonomy[edit]
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,[2] named after French chemist Claude Louis Berthollet.[22]
Distribution and habitat[edit]
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.[23]
Toxicity[edit]
Brazil nuts are susceptible to contamination by aflatoxins, produced by fungi, once they fall to the ground.[29] Aflatoxins can cause liver damage, including possible cancer, if consumed.[28] Aflatoxin levels have been found in Brazil nuts during inspections that were far higher than the limits set by the EU.[30] However, mechanical sorting and drying was found to eliminate 98% of aflatoxins; a 2003 EU ban on importation[28] was rescinded after new tolerance levels were set.
The nuts often contain radium, a radioactive element, with a kilogram of nuts containing an activity between 40 and 260 becquerels (1 and 7 nanocuries). This level of radium is small, although it can be about 1,000 times higher than in other common foods. According to Oak Ridge Associated Universities, elevated levels of radium in the soil does 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.[31] Radium can be concentrated in nuts only if it is present in the soil.[32]
Brazil nuts also contain barium, a metal with a chemical behavior quite similar to radium.[33] While barium, if ingested, can have toxic effects, such as weakness, vomiting, or diarrhea,[34] the amount present in Brazil nuts are orders of magnitude too small to have noticeable health effects.
Nutritional value per 100 g (3.5 oz)
2,743 kJ (656 kcal)
0.25 g
2.33 g
7.5 g
15.137 g
24.548 g
20.577 g
0.141 g
0.362 g
0.516 g
1.155 g
0.492 g
1.008 g
0.630 g
0.420 g
0.756 g
2.148 g
0.386 g
0.577 g
1.346 g
3.147 g
0.718 g
0.657 g
0.683 g
Quantity
Quantity
Quantity
3.48 g
1917 μg
64 mg