Many foods pack a big nutritional wallop into a small package, like the odd-sounding African oil bean seed. The plant is traditionally prepared into a fermented snack called ugba, which is an important source of protein in areas of the world where protein deficiencies are common. Although it may be difficult to find, you can use the African oil bean seed to make salads or as a highly nutritious snack.
The African oil bean seed, also known by its scientific name, Pentaclethra macrophylla, is native to tropical regions of Africa and has been cultivated since 1937. The glossy, brown seeds average eight in number and are contained in a flattened pod that explodes when ripe, dispersing the seeds. The seeds then require processing and fermentation before they can be eaten, although other parts of the plant are used in folk medicine and in wooden products and crafts.
African oil bean seeds contain up to 44 percent protein, with all twenty essential amino acids. The seeds also contain essential fatty acids within the seed oil, as well as many minerals, particularly magnesium, iron, manganese, copper, phosphorus and calcium, and trace amounts of vitamins. However, the fermentation process decreases the bean's levels of vitamin and minerals to the point where no phosphorus is found in ugba. The fermented ugba deteriorates rapidly and can spoil within two weeks of production.
African oil bean seed contains saponins, or phytochemicals found in most vegetables, beans and herbs, which have been linked to lower cholesterol levels, although the fermentation process may reduce these levels. John Ifeanyi Chidozie, MDcv., MFR, with the University of Nigeria, presented a paper at the UICC World Cancer Congress in 2006 claiming that patients who regularly consumed fermented oil bean seeds had a reduced risk of cancer and tobacco-related diseases. Research by P.A. Akah and colleagues in Nigeria, published in June 1999 in Phytotherapy Research, found that oil bean seed extracts were effective as antimicrobials and antispasmodics, as well as useful for treating diarrhea.
African oil bean seed and the fermented ugba can be found in specialty African food stores in the United States and Europe. To help avoid the problem of rapid spoilage, the products are often found wrapped in airtight cellophane or in frozen form. When first sliced, the ugba will be grayish-white, but after fermentation it turns dark brown. If you buy the seeds, you’ll need to boil them for up to 18 hours, slice them into thin strips, and then wash and ferment them for three to four days before use.
In a few studies, unfermented African oil bean seeds were found to contain traces of a poisonous alkaloid known as paucine, as well as small amounts of caffeoylputrescine, a growth depressant. Bacteria such as E. coli and Staphylococcus aureus, as well as molds that can produce mycotoxins in foods, have also been isolated in African oil bean seeds, but these substances are believed to be neutralized during the cooking and fermenting process.
- “Pakistan Journal of Nutrition”; Compositional Changes in African Oil Bean Seeds During Processing; V.N. Enujiugha1 et al.; 2005
- Cornell University: Physical Properties of African Oil Bean Seed
- ScienceDirect: The Nutritive Value of African Oil Bean Seeds
- The Smithsonian/NASA Astrophysics Data System: Characteristics and Composition of African Oil Bean Seed
- Science Alert: Ugba, the Fermented African Oilbean Seeds