Sounds exotic and it is. But the tonka bean is also becoming increasingly popular in Europe. We at Plantura are investigating.
Tonka - the name already sounds like tropical forests, colorful flowers and the confused chirping of birds and you can't go wrong with this association. Because the tonka tree (Dipteryx odorata) is an imposing tree that is native to the tropical regions of the American continent. In fact, it has been grown for centuries in northern South America, the rainforests of the Amazon, the Caribbean and Guyana. The trees reach a proud height of up to 30 meters and have a wide canopy as a crown. The tonka bean lolls along them. Strictly speaking, this is not a bean at all, but the seed in the fruit of the tonka tree. But if you think of a colorful fruit, you are wrong in this case, because the color of the Tonkafruit varies from gray to black and reaches a tender size of around two to five Centimeter. Even if the fruit does not shine like gold, it is of some value to the people living in the areas where it is grown. Until 1940 the tonka bean was and still was a common means of payment among the indigenous people of Venezuela Today the tonka bean is worn as a protective amulet against diseases or in the wallet as a Lucky charm. The word "Tonka" comes from the Caribbean language of the native French Guiana and means the tree. In Spanish, the tonka bean bears the name "cumarú", which indicates the ingredient coumarin. Originally, the interest was more in the tonka tree, which was often felled because of its wood. This is not only extremely durable, but also special thanks to its striking, dark to orange-red shimmering color. In the meantime, however, the demand for the tonka bean is also increasing, especially in the catering industry, as well as in the food and cosmetics industries. This is probably due to the fact that it exudes a captivating aromatic-sweet scent, comparable to a bourbon vanilla.
Synonyms: Counarouna odorata, Dipteryx odorata, Coumarou or cumarú
Cultivation of the tonka bean
The tonka tree belongs to the legumes, more precisely to the legume family (Fabaceae) to which the pea also belongs. Even the butterfly-shaped, purple or pink flowers on the tree look a lot like those of a pea and The flowering time in late spring to the end of summer is also characteristic of this Plant family. After flowering, the mango-like fruit grows out of the ovary with a leather-like skin and tasteless pulp. Inside it is a single, almond-shaped seed - the tonka bean. The aroma of the bean is similar to that of vanilla and the extracts are used both as a seasoning in cooking and for therapeutic purposes.
Even today, Nigeria and Venezuela are the countries with the largest exports of tonka beans. The trees also grow in rather nutrient-poor soil and prefer sunny locations, but need well-drained soil. Nevertheless, the tonka tree thrives best when it is cultivated in a very humus rich soil.
Late 18th In the 19th century, the first seeds of the tonka tree found their way to Europe and were cultivated in greenhouses in France. In our latitudes, it is extremely difficult to create the preferred climate for the tonka tree, even in the greenhouse, which is why we would only recommend it to professionals.
Harvesting and storage of the tonka bean
As soon as the fruits have ripened and fall from the tonka trees around May, the beans can be removed from the hard shell and collected. Ideally, you can achieve a yield of up to 15kg tonka beans per tree. The tonka beans get their coveted rum aroma by soaking them in rum before they are dried for months. Drying creates the typical brownish-black and wrinkled skin of the tonka bean. The tonka bean should be stored dry and cool so that it retains its great aroma for a long time. A tightly sealable can or a dark screw-top jar is best for this.
Ingredients and their effects
The best-known ingredient of the tonka bean is coumarin, which comes from the class of lactones. It also gives fresh hay and Woodruff its typical spicy smell. The average coumarin content is two to three percent, but peak values of up to ten percent can also be achieved. Coumarin has long been suspected of being carcinogenic and damaging to the kidneys and liver. For this reason, the tonka bean was banned in Germany for a while. This ban has only existed in a restricted form since 1991. On the one hand, this is due to the fact that the carcinogenic effect only occurs with artificially produced coumarin in very high doses on the other hand, the tonka bean is specially treated in South Africa, so that the coumarin content sinks. It is better not to exceed the maximum dose of 0.1 mg coumarin per kilogram of body weight. From an overdose of 500 mg per kg of body weight, this substance has a toxic and violent effect Headache, vomiting, dizziness, sleep addiction, central paralysis, respiratory failure and in the worst case scenario Coma. Since only extremely small amounts are used in the kitchen (the aroma explosion is enormous), coumarin poisoning is unlikely.
The tonka bean was already regarded as a natural remedy for body, mind and soul among the indigenous people of South America. In today's medicine, coumarin is used as a pain reliever and blood thinner. At the same time, it stimulates the production of serotonin in the body. Above all, alternative medicine makes use of the calming and relaxing effect and prescribes coumarin for insomnia and gastrointestinal complaints. The essential oil of the tonka bean has analgesic, relaxing and warming properties for tension and sore muscles.
Ethanol is required to produce coumarin, as it is only water-soluble to a limited extent.
Use in the kitchen
The tonka bean's unique aroma is often described as a combination of vanilla, almond, pear, and even fresh hay. It is precisely this fragrance that has been used in perfume production for years. This unique flavor combination is now celebrating its entry into the kitchens of the world. Tonka beans are often used in dessert preparation to create a complex and unique vanilla flavor. But you can also boil them with milk or cream and use them to conjure up ice cream, chocolate or mascarpone desserts. But the tonka bean also gives hearty dishes such as mashed potatoes, sauces and soups that certain something.
