Yesterday’s Celebrity MasterChef final left its audience with a head-scratching conundrum after former Pussycat Doll Kimberly Wyatt made a tonka bean and vanilla soufflé under the guidance of Michelin-starred chef Angela Hartnett.

headscratcherThe likely expression of most viewers when the arcane ingredient was announced. Image uploaded by johnny_automatic at Openclipart. The featured image for this article is from Flickr user Fred Benenson.

There were amusing sprinkles of confusion and speculation on Twitter:

Tonka Bean Tweets 2

I too made a link with Tonka trucks, then blurted out, ‘Back it up like a tonka bean. ¡Dale!’ in a weird homage to Pitbull’s line from the 2011 Jennifer Lopez hit, ‘On the Floor’.

Tonka Truck 1978A Tonka truck from 1978. Located via Wikimedia Commons.

Of course, no particular connection exists between tonka beans and Tonka trucks. The legendary brand was founded in Minnesota during the mid-1940s as ‘Mound Metalcraft’, a gardening equipment company. Following a business acquisition, they began making toy vehicles and changed their name to ‘Tonka’, taken from Lake Minnetonka. In the Native American Dakota language, mni is ‘water’, while tonka, tanka, or taåka is ‘big’. Minnetonka is therefore ‘Big Water’.

Lake MinnetonkaThe ‘big waters‘ of Lake Minnetonka, Minnesota. Picture from Flickr user edkohler.

Tonka beans are the seeds of the leguminous South American tree Dipteryx odorata. Around an inch in length, they are like blackish almonds or large raisins to the eye, with a scent similar to vanilla, if somewhat spicier. Shavings can be used to infuse dishes, with the whole product also being soaked in alcohol to extract its flavour.

The name derives from the term for the bean in Guyanese Creole. Its ultimate meaning is not known, but English variants in the eighteenth century included tonga, tonqua, and tonquin, as in this early example:

‘The tonquin beans are said to grow in a thick pulp, something like a walnut, and on a large tree.’

John Gabriel Stedman, Narrative, of a five years’ expedition (1796).

Tonka Beans JamieAnneTonka beans, photographed by Flickr user jamieanne.

In the Arawak tongue of the same region, the word is cumaru, which gave rise to ‘coumarin’, the name of the aromatic compound found in the seeds, chemical formula C9H6O2. Obtained in a crystallized form, this is used by the perfume industry when creating fragrances. High concentrations of coumarin can cause liver problems; food sources of the substance have been outlawed by the United States Food and Drug Administration since 1954, though two notable exceptions include cinnamon and liquorice. Ike DeLorenzo argues in a piece for The Atlantic that an individual would have to consume some 30 tonka beans in order to fall ill, with one providing enough shavings to flavour up to 80 plates of food – nutmeg has a similar toxicity. For all this, the exotic tonka remains a popular alternative to vanilla, used in sweet and savoury dishes alike.

Case closed.