thumb|Dipteryx odorata
Dipteryx odorata (commonly known as "cumaru", "kumaru", or "Brazilian teak") is a species of flowering tree in the pea family, Fabaceae. The tree is native to Northern South America and is semi-deciduous. Its seeds are known as tonka beans, but sometimes spelled tonkin beans or tonquin beans (not related to Tonkin). The seeds are black and wrinkled and have a smooth, brown interior. They have a strong fragrance similar to sweet woodruff due to their high content of coumarin.
The word tonka is taken from the Galibi (Carib) tongue spoken by natives of French Guiana; it also appears in Tupi, another language of the same region, as the name of the tree. The old genus name, Coumarouna, was formed from another Tupi name for the tree, kumaru.
Many anticoagulant prescription drugs, such as warfarin, are based on 4-hydroxycoumarin, a chemical derivative of coumarin initially isolated from this bean. Coumarin itself, however, does not have anticoagulant properties.
Biology of the tree
The tree grows up to , with a trunk of up to in diameter. The tree bark is smooth and gray, whereas the wood is red. The tree has alternate pinnate leaves with three to six leaflets, leathery, glossy and dark green, and pink flowers. Each developed fruit contains one seed. D. odorata is pollinated by insects. The worst pests are bats because they eat the pulpy flesh of the fruit. A few known fungi may cause problems: Anthostomella abdita, Diatrype ruficarnis, Macrophoma calvuligera and Myiocopron cubense.
Seeds
The tonka seed contains coumarin, a chemical isolate named after the plant. The seeds normally contain about 1 to 3% of coumarin, but can rarely achieve levels up to 10%. Like a number of other plants, the tonka bean plant probably produces coumarin as a defense chemical.
thumb|The smooth brown inside of the tonka bean
Uses
Tonka beans have been used as a source of natural coumarin and, after its synthesis in the 1940s, artificial coumarin became one of the first artificial flavoring agents as a vanilla substitute. The Food and Drug Administration in the United States has considered foods containing tonka beans adulterated since 1954 because coumarin has shown toxicity in extremely high concentrations. Despite the American ban on its use in foods, the product has been frequently imported into the US by gastronomic enthusiasts. There have been calls for removing the restrictions on the use of tonka beans in food in the US similar to the successful deregulations of mangosteens and absinthe in the early 21st century.
In France, tonka beans are used in cuisine (particularly, in desserts and stews) uses them in their men's perfume Hoggar, for example, and they are still used to flavor some pipe tobaccos, such as Samuel Gawith "1792 Flake."
Many anticoagulant prescription drugs, such as warfarin, are based on 4-hydroxycoumarin, a chemical derivative of coumarin initially isolated from this bean. Coumarin, however, does not have anticoagulant properties.
Cultivation
Today, the main producers of tonka beans are Venezuela and Nigeria. The cumaru tree is a light-demanding calcifuge tree which grows on poor, well-drained soils. The best growth is reached on fertile soils rich in humus. In the native region there is a mean annual temperature of 25 °C and about rainfall per year, with a dry season from June to November. In general, it has a very low plant density, but depending on the agricultural use, the density and the age of the trees diversify. In seed production systems, the plant density is higher and the trees are older than in timber production systems.