Breu-Branco

Breu branco is the oily resin that Protium heptaphyllum, a tree of the family Burseraceae, exudes from its trunk. Other members of the Burseraceae also exude such a resin. The tree is known as almécega, breu and almíscar, and it originated in South America. It is a large evergreen tree that can grow to be 10 to 20 meters tall.

The resin holds a mixture of triterpenes of the α-amyrin (ursane) and β-amyrin (oleane) series, together with an essential oil rich in mono- and sesquiterpenes. Acidic triterpenes make up 23.4% w/w of the raw resin. Monoterpenes are the main constituents of the volatile fraction, in the range between 85% and 98%. The volatile fraction of the resin includes the monoterpene hydrocarbons α-pinene, α-phellandrene, δ-3-carene and p-cymene. In one analysis the most abundant volatile compounds in the resin were α-pinene at 1.26% w/w and p-cymene at 1.11% w/w. The total content of volatile compounds in that resin was 5.07% w/w. Sesquiterpenes are present only to a limited extent. In the oil extracted in 2009, the major constituents were 3-carene, limonene and terpinolene. The volatile fraction also holds the oxygenated monoterpenes 1,8-cineole, trans-verbenol, terpinen-4-ol and p-cymen-8-ol, and the sesquiterpene β-E-caryophyllene.

The resin is traditionally used by the Amazon local population for making varnishes, wood boat sealants, fumigants and insect repellents. The resin has medicinal and insecticidal properties.

The tree

The tree is commonly found in Brazil, the Guyanas and Venezuela, and it flourishes in Amazonia, where it occupies the tropical rainforest. It is cultivated throughout Brazil because it adapts to sand and clay soils, but it cannot be cultivated in swampy soils or next to rivers with constant flooding. Local people harvest it for resin, food, wood and medical uses. The fruits, which appear from January to March, have a sweet and refreshing pulp that can be eaten fresh. The reddish wood is used in construction, floors, carpentry and joinery.