One of the two foods highlighted in my chapter about soybeans in Africa in The World of Soy (published already 8 years ago now) was a pungent West African condiment, traditionally made with “African locust beans” but
One of the two foods highlighted in my chapter about soybeans in Africa in The World of Soy (published already 8 years ago now) was a pungent West African condiment, traditionally made with “African locust beans” but increasingly with soybeans, and known by various names such as: sumbala, sunbala, or sungala (in Manding); daddawa or dawadawa (in Hausa); iru (in Yoruba); netetu (in Wolof); and ojji (in Fula). The other food was tofu, which is also an interesting development, but here I’ll focus only on the condiment, and the ongoing natural resource issues behind a shift in its main ingredient.
Increasing use of soybeans is a good story, but the decrease in use of locust beans is not, reflecting declining numbers of African locust bean trees due to loss, low regeneration, and little planting, and decreasing production by existing trees where rainfall levels have gone down.
What is sumbala…?
Sumbala – I’ll use the term from Manding here, although I used the Hausa term in the book chapter – is widely used across West Africa to season sauces. The process of making sumbala centers on fermentation of seeds, most commonly those of the African locust bean tree, Parkia biglobosa (among the traditional alternatives is a close relative of the more humid tropics, P. bicolor). More about the tree and what’s happening with it in a moment, but about its seeds – evidently they are quite nutritious. Locust beans have high protein (like distantly related beans) and various other nutrients. The fermentation process, aside from changing taste, also affects the profile of available nutrients.
Production of sumbala – generally done by women as a home-based industry – is a multi-step process from preparing the seeds to boiling them to setting them aside in the proper conditions to ferment (without innoculent to get the fermentation started). The bacteria of the fermentation are in the Bacillus group, primarily Bacillis subtilis (a variety of the latter is also used to ferment soybeans in a somewhat different process to make a Japanese food called nattō 納豆).
The final sumbala product can be seen in local markets as a ball or patty. These may be traded at some distance within the region. Nowadays it is also packaged in a crumbled form for sale in urban markets and for export.
African locust bean tree, or nere
Parkia biglobosa, often called in English African locust bean tree, or more rarely African carob, is common in Africa, and especially West Africa, roughly between 5°N and 15° N latitude – from the edge of tropical forests to the edge of the desert (“mean annual rainfall” of 400-700mm). The tree of course has names in the various languages of the region such as: nɛrɛ or nɛtɛ (Manding); ɗorawa (Hausa); irugba (Yoruba); uul (Wolof); and nareewi or netehi (Fula). “Néré” in French and English comes from the Manding, as evidently do the Fula terms.
The tree is valuable for its seeds, of course, and also for other products, such as the nutritous yellow pulp of the pods. The Lost Crops of Africa (vol. 2) chapter on the African locust bean tree discuses some of those uses. In terms of traditional medicine, bark and leaves are apparently effective in treatment of some infectious diseases.
Due to its value, the locust bean tree is usually conserved in fields when most other woody plants would be cleared. However it has been noted for a while that natural regeneration is apparently not sufficient to replenish the population – which recent studies from Burkina Faso and Nigeria confirm. Reasons given for this include the harvest of the seeds for sumbala, and loss of seedlings to drought or browsing livestock.
Efforts to plant African locust bean trees are apparently few, even though it is simple to seed directly or produce in nurseries.* One example of planting in southern Burkina Faso is interesting but seems to be limited in scope. It is not clear whether planting this species is part of any large scale project or extension effort, although it was mentioned in a 2010 recommendation of species for the Great Green Wall project.
Another challenge is lower rainfall levels, which aside from affecting survival of seedlings also lower production of seed pods – as observed in another example from Burkina Faso.
Soybeans to the rescue?
It is in this environment, with generally declining availability of locust beans but increasing markets for sumbala, that soybeans emerged as an alternative. This substitution is described in 