Bambara groundnut (Vigna subterranea), also known as voandzou, is the third most important legume in Africa after peanut (Arachis hypogaea) and cowpea (Vigna unguiculata). Native to West Africa, Bambara groundnut has been heavily displaced by introduced crops with greater economic potential, such as peanut. Bambara groundnut is, nonetheless, still widely grown and is an important crop for the food security of rural households in semi-arid sub-Saharan Africa. Considering its widespread cultivation, the crop has received limited attention to raise its yields or marketing potential to improve its contribution to local livelihoods and nutrition.
Bambara groundnut is capable of producing in poor-fertility soil, is drought tolerant and resistant to pests and disease, all without the presence of chemicals and fertilizers, which are often expensive or difficult for smallholders in Africa to access. Like other legumes, Bambara groundnut contributes to soil fertility through nitrogen fixing and is thereby useful in crop rotation systems. Bambara groundnut seeds range from round to elliptical in form and can be cream, red, or black in color.
Bambara groundnut is an excellent source of fibre, iron, potassium, calcium, and several B vitamins. It is a good source of protein, fat and carbohydrate, with sufficient levels to be considered a complete food. It contains similar levels of protein as other important legumes in Africa such as cowpea and peanut. Although Bambara groundnut is deficient in amino acids methionine and cysteine, it surpasses the levels found in cowpea, peanut, and pigeon pea, and contains all other essential and non-essential amino acids. It also generally has comparable levels of calcium, iron, zinc, copper, potassium and magnesium. Red-colored seeds contain twice as much iron as cream-colored seeds. Tannins and trypsin inhibitors are anti-nutrients found in Bambara groundnut that limit protein absorption, but dehulling and other preparation methods, such as boiling, reduce their activity. Dark-colored seeds have been found to contain higher concentrations of tannins, therefore light-colored seeds may be preferable to improve nutrition and reduce the cooking times needed to break down tannins.
Harvesting of Bambara groundnut occurs roughly four months after sowing. Because the pods are produced underground, they are difficult to harvest mechanically. They are typically harvested manually by pulling or lifting the plant
Dehulling of Bambara groundnut seeds can be burdensome due to the high concentration of fiber and protein-starch complexes in the cell walls. Immature pods may be eaten as a fresh snack, roasted, boiled, or crushed for use as a condiment. Mature seeds are boiled and require more time to cook due to their harder coats. Boiling fresh nuts takes 45-60 minutes, while dried nuts may take as long as three to four hours. Due to longer cooking times compared to other legumes, Bambara groundnut requires more fuel and water to process. It can be ground into flour to add nutrient value to a variety of foods. However, due to its fibrous shell, it shows poor milling characteristics.
A holistic approach addressing multiple bottlenecks in supply and demand is being applied for Bambara groundnut in Mali through the project “Linking agrobiodiversity value chains, climate adaptation and nutrition: Empowering the poor to manage risk”. Multiple stakeholders are being consulted and involved to devise value chain interventions that are pro-poor and gender-sensitive. Led by Institut d'Economie Rurale (IER), key actions being taken are participatory evaluations of diverse landraces and improved varieties to identify well-adapted materials, training women on processing methods and novel recipes, investigating and introducing processing technology to reduce drudgery, and building collective action and communication among stakeholders to improve the organization of the value chains and farmers’ income. Sensitization and awareness raising on the value of Bambara groundnut for nutrition and climate resilience is aimed to increase demand and consumption of this important crop by the participating communities. Read more about this work, ongoing from 2015 to 2018 on the IFAD-EU NUS Project page.
