An EU-backed study into the marama bean (Tylosema esculenta) has revealed potential for it to yield small quantities of high-value oil as well as nutritious food products or ingredients.
Whether any commercial success is gained from the marama bean (pictured above) following the study should also be instructive for entrepreneurs considering commercial development of other indigenous crops and fruits.
The marama bean is a legume, but has such a hard husk (seed coat) it seems like a nut. The beans grow on vines on the ground in arid and semi-arid, sandy regions of South Africa – the Kalahari desert of Namibia and Botswana; Zimbabwe; South Africa’s Limpopo, North-West and Gauteng provinces. They are called by different names – mangetti, tsin, braaiboontjie, etc.
Different varieties of the bean may occur on the east side of Africa and even possibly in the dry parts of West Africa.
The beans grow wild and have never been "domesticated" or cultivated. The kernels (actually cotyledons) used to form part of the diet of the Bushmen and they are still commonly eaten by traditional communities where they occur – mostly as a roasted nut snack or mixed with cooked dishes. The beans are also traded to a limited extent on local markets in, for instance, Botswana.
The plant’s large tuber roots are also boiled and eaten.
But commercial development of the kernels is virtually nil – probably because the plant is only known in these remote, normally poverty-stricken areas.
The recent three-year study was conducted by universities in South Africa, Botswana and Namibia as well as universities and research institutes in Europe. The EU backed the study to promote food security in the region.
Broadly, the research has shown that even though there are limitations on the quantities of marama beans which could be produced (for instance, the plants do not yield fruit as copiously as do marula trees), they can be relatively easily grown through "wild" propagation – without ploughing etc.
An advantage is that (unlike marula) the beans have long shelf life after harvesting – because of their husk, they can be kept almost indefinitely for later use or processing.
Although production quantities are currently a limiting factor, it is likely that if there was a lucrative enough combination of markets, local communities would propagate them and production would increase.
Of course a problem with all wild, indigenous crops is that there should not be over-harvesting of wild fruit.
In southern Africa, for instance, marula has become a relatively successful indigenous fruit which is now found in a number of processed products. Baobab fruit appears to be following marula, but concerns are being raised about over-harvesting in the absence of cultivated orchards.
What the marama might lack in quantity, it seems to make up in quality, however, because the study revealed that the beans could yield a "cornucopia":
* They are high in oil (32-42%) – a similar percentage to peanuts, for instance. But the oil has a similar nutritional profile to olive oil – it is rich in mono- and di-unsaturated fatty acids and contains no cholesterol. Perhaps more important than this, the oil has sometimes been used in traditional communities for cosmetic purposes and is likely to have qualities beneficial to the skin (current analysis of its chemical properties, being done at the University of Botswana, may confirm this).
This aspect is important because of, for instance, the experience of avocado oil. Edible avocado oil is a recent advent to the mainstream market but although it attracts relatively high prices relative to some other edible oils, the price of what is perceived to be the top edible oil – olive oil – forms a ceiling for avocado oil’s price. However if avocado oil is used for cosmetics purposes, no such ceiling exists, so a much higher price can be achieved. Because of the relatively low amount of marama beans that could be harvested from traditional wild sources, a high value for oil extracted (for cosmetics applications) would contribute considerably to its viability. This might be the spark to commercial development of marama beans, according to Danie Jordaan, a consultant from Market Matters Inc, who worked on the EU project. He believes marama oil could attract good prices because of its scarcity and novelty. There are many traders and niche markets for novelty oils -especially if they are marketed with a "good story" as could easily be formulated for marama. Purchasers like The Body Shop might, for instance, combine marama oil with essential oils which have known therapeutic applications.
The experience of marama beans might prompt entrepreneurs to look at other indigenous crops/fruits to see whether niche oils and other products could be produced from them. The price of niche oils varies considerably – see accompanying table.
* The kernel contains no starch but is high in protein (29-38%) and dietary fibre (19-27%). Roasting of the beans makes the protein more bio-available. The kernel is also low in sodium and chlorine and is high in potassium, phosphorus and calcium. Marama is also a potential source of phytonutrients.
All this provides the opportunity for using the kernel for localised/traditional niche food products or for supplementation of current more mass market products – probably after the oil has been extracted. At this stage nobody is suggesting that marama beans could provide any competition for mass-produced, westernised, branded food products.
For instance marama’s kernel (cotyledon) has a similar amino acid profile to soybeans, and soy-derivative products produced on an industrial scale would be its biggest competitor. As with soy beans, a variety of products could theoretically be produced from marama – flour, milk, roasted nuts, butter, yoghurt, cookies, etc. But in fact there would be no contest given the huge momentum of industrialised soy.
Another way to enhance marama’s viability would be to harvest them with other wild/indigenous fruit/crops. Says Norman Npedi, founder of Nguni Juice, which produces a range of indigenous fruit juices at a facility near Mokopane in South Africa’s Limpopo province: "For viability, it helps to harvest a number of different fruits in the wild."
Some researchers believe that there are a number of other foods that could be harvested in areas where marama occurs, to make juices, etc.
A major consideration in processing the marama bean is that the husk is hard to crack – it takes considerable manual labour to extract the kernel. The husk is harder than that of a macadamia nut, but similar technology to that used to shell macadamias it is used. The process is however easier than the extremely hard process of extracting marula kernels.
* Material for this article was primarily drawn from a workshop held on Small-Scale Processing and Marketing of Oilseeds and Legumes, organised by the University of Pretoria’s Department of Food Science.
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