The Delicious Flavour with a Toxic Secret
Tonka beans have an intense flavour that chefs and food manufacturers have enthusiastically embraced. There’s just one problem – it contains a chemical that could, in large enough doses, kill you.
It’s led to raids by law enforcement agencies and mass deaths in animals; in the United States, chefs have ‘dealers’ who smuggle it into the country. Given these facts, I’m unwrapping my online delivery with a level of suspicion usually reserved for bomb disposal. Inside is a jar of wrinkled black beans, each resembling an elongated raisin. These are ‘token beans’ – the aromatic seed of a giant tree from deep in the Amazon rainforest.
When grated into desserts or infused into syrups, they impart a flavour so transcendent, tonka has been dubbed the most delicious ingredient you’ve never heard of. Notes of freshly cut
grass mingle with vanilla, liquorice, caramel and clove, topped off with a suggestion of warmth and a
hint of magnolia – that is, according to the internet. I unscrew the lid and take a whiff. They smell faintly like furniture polish.
Tonka Bean in Gourmet Desserts
“As long as you don’t use a copious amount of it – obviously a copious amount could cause
death – it really is delicious,” says Thomas Raquel, head pastry chef at the Michelin starred
Le Bernardin in New York, not particularly reassuringly. Selling tonka beans to eat has been Illegal in the US since 1954. Foods containing tonka are considered to be ‘adultterated’, though that hasn’t stopped them appearing on the menus of Michelin starred restaurants, from New York to California.
In fact, the United States is the biggest importer of tonka on the planet. Tonka beans Flavour contain unusually high levels of the chemical coumarin, which gives them their flavour and is found naturally in hundreds of plants, including grass, lavender and cherries.
“ It was widely used in place of natural vanilla, added to chocolate, sweets and cocktail bitters, vanilla essence and even soft drinks.
Coumarin was first isolated from tonka beans in 1820 – the name comes from the caribbean term
for the tonka tree, ‘coumarou’ – shortly afterwards, an English chemist better known for inventing the first synthetic dye worked out how to make it in the lab.
Tonka Bean in Meal
By the 1940s, artificial coumarin was really taking off. As one of the first synthetic additives, it was dirt cheap. It was widely used in place of natural vanilla, added to chocolate, sweets and cocktail bitters, vanilla essence Flavour and even soft drinks. It swiftly became a staple ingredient in tobacco and lent it’s complex aroma to the perfume industry.
But there was a problem. Studies in dogs and rats had revealted it to be toxic, with relatively low levels causing considerable damage to the liver in just a few weeks. In sheep, just 5g (around two teaspoons) is fatal. Both tonka and coumarin were outlawed.
This is despite a government crackdown nearly a decade ago, including raids on several gourmet restaurants. Grant Achatz, who is head chef at Chicago restaurant Alinea, later told The Atlantic ” They [the supplier] said, Don’t be surprised if the FDA shows up soon’ Two days later they walked in: ‘Can we look at your spice cabinet?'”.
Tonka and coumarin both still regularly turn up in Mexican vanilla flavouring, where they’re used to mask a low quality product. “I was talking to a vanilla Flavour purveyor recently and he offered me tonka bean paste,” says Raquel. “I was like ‘If I want too use tonka bean, I’ll use tonka bean.'”
Flavour Even if fancy restaurants aren’t your scene, there’s a good chance you’re being exposed from other sources. It’s still perfectly legal to add coumarin to tobacco and cosmetics, though it’s easily absorbed through the skin and the fragile lining of the lungs.
Different Countries
The chemical is used copiously in detergents, shower gels, hand soaps and deodorants and blockbuster scents such as Coco Mademoiselle (Chanel) and Joop! Homme. It’s even found it’s way into e-cigarettes.
In fact, there’s a good chance you’ve got some coumarin lurking in your kitchen cupboards.
True cinnamon is made from the bark of the plant Cinnamomum verum
(also known as Cinnamomum zeylanicum) and is native to Sri Lanka. This type naturally has extremely low levels of coumarin and proven medicinal properties, but that’s probably not what you’ve
got in your spice rack. That’s because what we think of as cinnamon isn’t really cinnamon at all, but a Southeast Asian imposter made from the bark of the cassia tree.
“ Coumarin is mostly toxic to the liver, which plays a central role in mopping up poisons and clearing them from the body & nbsp;
Though the plants are distant cousins, cassia cinnamon contains around 25,000 times more coumarin. The US doesn’t regulate the amount of coumarin in cinnamon, though the European Union has set safe daily limits – and just one teaspoon of cassia cinnamon could send you over.
In 2013 Denmark’s beloved kanelsnegle, or cinnamon rolls, narrowly escaped being banned
after a study found that nearly half of the products tested exceeded the maximum coumarin content allowed in food. “Only very rarely do we find an exceedance of a toxic compound in such a high percentages
of foods,” says Nicolai Ballin, a food chemist from the Danish Veterinary and Food Administration who
authored the study. “The worry is that many of these products are aimed at children.”
Token Bean
So how dangerous is coumarin really? On paper at least, the forbidden flavour has never caused a single human death and there have been calls to lift the ban. But that’s not quite the full story.
Tonka beans have an intense flavour that chefs and food manufacturers have enthusiastically embraced. There is just one problem – it contains a chemical that could, in large enough doses, kill you.
Given these facts, i’m unwrapping my online delivery with a level of suspicion usually reserved for bomb disposal. Inside is a jar of wrinkled black beans, each resembling an elongated raisin. These are tonka beans – the aromatic seed of a giant tree from deep in the Amazon rainforest.