Now you may or may not be aware of these so-called “sinful” tonka beans, but it is likely
that you have chanced upon their wrinkly, black textures at a local spice shop, knowingly
or unknowingly.
Perhaps you may have even caught a whiff of them while digging in your favorite Le Gateau,
honeyed apricot cake or crème brûlée!
The Food and Drug Administration’s call for their ban in the 1950s hasn’t really
prevented them from making their way to the haute cuisine of elite restaurants, including
the crème de la crème Michelin-starred ones!
Wondering what exactly are these flavorful beans and why have they been banned in the
US?
Eager to find out what is it about the distinctive aroma that makes the tonka beans an integral
part of gourmet desserts and utterly desirable for chefs worldwide?
Let’s reveal it all for you.
Origin of the Tonka Beans Dipteryx Odorata is a species of Fabaceae,
a family of flowering plants commonly referred to as the legume, pea or bean family.
Also popular as “cumaru” or “kumaru”, the tree is native to Central America and
to South America, in particular to the dense Amazon rainforest in northern South America.
Dipteryx Odorata is the source of the tonka beans which are contained as seeds within
the fruits borne by this tree.
The seeds can be easily recognized by their crinkly, black exterior (almost a raisin lookalike
but with an elongated and hardened appearance) and a contrasting smooth and brown interior.
The derivation of the word “tonka” can be traced to the Galibi or Carib language
spoken by the indigenous people native to French Guiana.
The word also finds mention in the region’s Tupi language which makes use of the term
“tonka” to indicate this tree.
How Do the Tonka Beans Get Their Characteristic Aroma?
Tonka beans emit an intoxicating fragrance, often described as a heady spicy-fruity mix
of cinnamon, vanilla, almond and cloves.
Some even claim to register a distinct cherry-like aroma or sandalwood notes while few others
assert that the tonka’s strong scent is reminiscent of licorice and caramel.
“To each his own”, we say!
The unmistakable scent of these beans is attributed to a fragrant chemical isolate called “coumarin”
which is naturally present in these beans in high content.
Apart from the tonka bean plant, the bitter-tasting substance is found in many other plants, including
grass, lavender, cinnamon, cherries etc.
It is presumed to be produced by plants as a defense chemical in response to a perceived
threat or attack.
Coumarin is identifiable by its sweet odor which has been likened to that of newly mown
hay and fresh-cut grass.
It derives its name from the French word “coumarou” that is symbolic of the tonka bean tree.
Isolation, Synthesis and Usage of Coumarin Coumarin was first extracted from the tonka
beans in 1820 and first synthesized in 1868 by the English chemist, William Henry Perkin.
Its use in perfumes dates back to 1882 while the popularity of synthetic coumarin increased
manifold by the 1940s.
Today, the sweet-smelling chemical finds extensive usage in the formulation of perfumes, deodorants,
detergents, fabric conditioners, toiletries and cosmetics.
It is also leveraged to boost the aroma of pipe tobaccos, e-cigarettes, chocolates and
alcoholic drinks; not to forget its use as a flavor enhancer, especially as an artificial
vanilla flavoring.
The actual tree or cumaru is widely used in the United States for the purpose of flooring,
owing to the hardwood’s inherent durability and its attractive natural color variation.
Ban of Tonka Beans in the United States Despite many celebrated chefs and gastronomes
declaring the tonka as “the most delicious ingredient you have never heard of”, the
beans remain as elusive as ever in the US.
This is because of the ban imposed on coumarin in 1954 when the use of tonka extract for
the purpose of consumption was declared as “illegal”.
Even today, food preparations containing tonka are considered as “adulterated” - a fact
that has not stopped the immensely popular tonka from appearing on the menus of fancy
restaurants across the country!
Such is the craze for the mystical aroma of these beans that top chefs across gourmet
restaurants have found an underhand means to get them sourced through dealers who smuggle
the tonka beans into the country on behalf of the chefs!
Well, you can hardly blame the chefs!
Who wouldn’t want to get their hands on these intensely flavored beans, the minutest
trace of which is enough to render a dish with an unforgettable flavor?
A single bean’s shavings can actually have one covered for 80 plates…it’s that potent!
Purported Toxicity of Coumarin You may be thinking, “If they are that effectual,
then why were they outlawed?”
According to studies conducted on dogs and rats, relatively low quantities of coumarin
were found to have caused significant damage to the livers of these animals within a short
span of few weeks.
Moreover, just 5 g or approximately two teaspoons of coumarin proved to be fatal in sheep.
This led to the propagation of the theory that ingestion of coumarin in high doses may
result in chemical-driven hemorrhages, hepatotoxicity or paralysis of the heart in humans.
It is said to be particularly toxic to the human liver, thought to cause the latter slow
and progressive damage, akin to the organ’s prolonged abuse by continuous intake of alcohol
over several years.
Consequently, the use of coumarin and its source (tonka seeds), as food additives, is
regulated in many countries, including the US where it is banned for use in the food
industry.
While there are no official reports of any human casualty arising out of coumarin-induced
toxicity, safety limits have been put in place by many countries in relation to humans’
daily intake of the extract.
In the United States, the FDA has been busy busting the kitchens of chefs who are suspected
of secretly procuring and hoarding tonka beans in their spice racks.
Despite such raids in place, the US remains the world’s biggest importer of this delicious
but deadly spice!