Edward George Irving (1816-1855) was a Scottish surgeon who knew western Africa well, having traveled there when he served as a member of the Royal Navy aboard the HMS Prometheus.
In 1853, Irving stated during his testimony to the House of Commons Select Committee on Slave Trade Treaties (appointed to investigate the status of the treaties regarding the abolishment of slavery between Great Britain, Spain and Portugal) that he was “employed on the whole of the west coast of Africa, from north of Sierra Leone to the Bight of Benin; the river Congo, and as far south we had been as Little Fish Bay.”
But while in Africa, he was most likely more interested in looking for unique plants than for evidence of the slave trade. He is, after all, best known for being a botanist and plant collector. Both the plant family Irvingiaceae and genus Irvingia are named for him.
The African and Southeast Asian trees that make up the Irvingia genus are known by their common names — wild mango, bush mango, African mango — so-called for their small, edible yellow and green mango-like fruit. Squeeze it and you’ve got “African mango juice.”
One of the Irvingia species is the dika (Irvingia gabonensis), a tree so important that “when forests are cleared in West Africa for firewood or for farmland…[they] are more often than not, left untouched,” according to Molly Theobald of the Worldwatch Institute. “Farmers have too much to gain from harvesting the tree’s fruits and seeds to burn or discard a dika found in the wild.” And though its wood is a sturdy, termite-resistant building material, the dika is much more valuable as a fruit-bearer.
In addition to the dika’s edible fruit, there is the soft almond-like kernel of the drupe’s stony nut, which is an important food source. Almost a tenth of it is pure protein. A fifth carbohydrate. And more than 5 percent dietary fiber. Ogbono soup, a delicacy in Nigeria, Ghana and Gabon, is made from vegetables and powdered dika kernel. The seeds can also be pressed into an edible oil that is used to make soaps, cosmetics, candles, edible fats and even pharmaceutical binding agents.
But getting to this magical kernel is no easy task, a fact that led to the creation in 2008 of a table-mounted device for cracking the dika nut, by B.S. Ogunsina, O.A. Koya and and O.O. Adeosun, researchers from Obafemi Awolowo University in Ile Ife, Nigeria.
“The major limitation in the exploitation of dika kernel is the drudgery involved in its extraction,” the authors state in their report.
“Rural women who do most of the cracking hold the wet nut, one at a time, against a hard/stony surface to split it open with a machete along its natural line of cleavage; or when sufficiently dried, it is broken one at time between two hard surfaces. The nut cracking process is, therefore, cumbersome and usually, a large percentage of the kernels are broken.”
So they built a machine, and they found that “the ease and the safety in operating the device are commendable.”
But to get a sense of just how transformative — and delicious — the dika kernel can be, one must refer to its name when ground into a paste: Gabon chocolate.