Developing countries are faced with many food-related challenges, especially as it pertains to meeting the increasing food demand. As a result, several approaches have been adopted as a means of augmenting other main staple foods to address the issue of malnutrition and poor feeding in these parts of the globe. The African oil bean seed is a nutrient-packed natural food that has remained untapped and underused, thus calling for immediate attention to be widely exploited.
Even though there are several staple foods such as rice, maize, beans, etc., there are still great needs to supplement these food products with certain unpopular foods that are equally packed with loads of essential nutrients and vitamins needed for the healthy functioning of the body. I suppose that the basic privilege of everybody ought to be channeled towards having easy access to proper feeding and balanced nutrition, as any failure to do so can result in poor health and subsequent mortality.
One of such unpopular but yet essential food is the African oil bean seed, botanically known as Pentaclethra macrophylla, a tropical tree crop that belongs to the leguminoseae family and the mimosoideae sub-family. Different Nigerian tribes have different names for the African oil bean; for example, it is known as ukpaka or ugba in Igbo, the Yorubas call it Apara, while the Efik tribe call it Ukana.
But what exactly is Ugba, and how is it prepared? This article delves into the nutritional values, benefits, and traditional preparation methods of Ugba, shedding light on this essential African food.
Pentaclethra macrophylla fruits
Read also: Atlanta Nigerian Passport Services
Description of the African Oil Bean Tree
The African oil bean tree grows approximately 6 meters in girth and 21 meters in height. The tree is low-branched with low wide buttresses and an open crown that allows light to penetrate under its canopy. The bark has a reddish-brown to gray color with irregular patches that usually flake off. The African oil bean leaves are characterized by a big angular stalk that measures about 20-45 centimeters long. The leaves are glabrous in appearance and are equally covered with rusty hairs with 10 to 12 pairs of stout pinnae. The tree trunk oozes out reddish-orange colored fluid when cut and is equally buttressed and crooked.
The most widely used part of the African oil bean tree is the seeds, which are usually enclosed in flat pods that tend to burst once matured, thereby distributing the seeds all over the area in which the tree covers. The pods measure about 35 to 45 centimeters long by 5 to 10 centimeters broad. The pods are black in color, quite hard and woody in appearance, while the glossy seeds are normally 5 to 8 in each pod and are brownish in color.
Nutritional Values of African Oil Bean Seeds (Ukpaka)
African oil bean seeds are an excellent source of energy, protein, amino acids, phosphorus, magnesium, iron, vitamins, calcium, manganese, and copper. The high content of other essential amino acids makes the seeds a potential source of protein (Achinewhu, 1982). It is also an excellent source of phytonutrients such as tannins, alkaloids, flavonoids, sterols, glycosides, and saponins.
The seeds contain 4-17% carbohydrate, 44-47% oil which has been found to be rich in oleic acid (Nwokedi, 1975; Odoemelam, 2005) and linoleic acid (Onwuliri et al., 2004). Both saturated and unsaturated fatty acids are found in the seeds.
While some studies reveal that the fermentation process which they undergo before consumption usually eradicates most of these minerals and vitamins such as phosphorus the fermentation of African oil bean seeds increases pH toward alkalinity (pH 8). It is therefore possible that some organisms that are of public health concern could survive the fermentation process. Whether the presence of these organisms is as a result of post-fermentation contamination or they survive the fermentation process, their presence in the product portends great danger to the consuming public.
Read also: Experience Fad's Fine African Cuisine
Table 1 shows the amino acid profile of the seeds. Glutamic acid appears to be the largest amino acid contained in the seeds. Aspartic acid, lysine, and phenylalanine are also present in appreciable amounts in the seeds. This may be responsible for its use as a flavoring for soups in southeastern Nigeria.
How to make Ugba 🥣
Table 1: Amino acid content (g/100 g protein) of African oilbean seeds
| Amino Acid | Content (g/100g protein) |
|---|---|
| Aspartic acid | 9.4 |
| Glutamic acid | 17.6 |
| Lysine | 7.0 |
| Phenylalanine | 5.8 |
Benefits of the African Oil Bean (Ukpaka)
Both the seeds, leaves, stems, barks, trunks, and roots of the African oil bean tree are very useful for medicinal, edible, and commercial purposes.
- Cancer Reduction: Studies reveal that the African oil bean seeds are capable of reducing cancer growth.
- Culinary Uses: African oil bean seeds can be cooked, sliced, and allowed to undergo a fermentation process for three days before being used for preparing assorted delicacies such as ugba and okporoko, sausages, nkwobi, porridge, abacha salad, soups, and vegetables yam. The processed seeds are known as ugba or ukpaka.
- Treatment of Gastrointestinal Diseases: The leaves, stems, and bark of the African oil bean seed can be decocted and used for treating gastrointestinal diseases such as diarrhea.
- Commercial Purposes: The African oil bean seeds are an excellent source of oil thus can be used commercially for producing soap, candles, and cooking oil. The edible seeds are enclosed in brownish shells, which can be used for decoration and for making beads, traditional dancing costumes, dresses, rosaries, hand bangles, bags, and necklaces. The wood serves as firewood and can also be used for generating charcoals.
- Lowers Cholesterol Level: African oil bean seed is a rich source of saponins, which have been proven effective for reducing the plasma cholesterol; however, it is important to note that saponins are toxic.
- Anthelmintic Properties: The bark of the African oil bean tree exhibits anthelmintic properties thus can be used for preparing herbal medicines for treating and destroying parasitic worms.
- Animal Feed Production: African oil bean seeds are a rich source of nutrients such as amino acids, minerals, proteins, and fatty acids thus have been proven essential for use in the production of animal feeds, especially when fortified.
- Antibacterial Properties: African oil bean seeds contain saponins and alkaloids that possess antibacterial properties thus can be used for fighting Bacillus cereus, Staphylococcus aureus, Klebsiella pneumonia, and Bacillus subtilis.
- Antimicrobial Properties: African oil bean contains sterols which have been proven effective for tackling microbes such as Staphylococcus aureus.
- Treatment of Leprosy: The anthelmintic bark of the African oil bean tree can be crushed and decocted for treating leprosy sores.
- Farming Purposes: The wood and leaves can serve as mulch that can be spread around or over other growing plants to enrich or insulate the soil. The wood can serve as a stake for supporting other growing plants such as yam, running beans, akidi. The trunk can serve as timber that can be used for structural work.
- Infertility Treatment: African oil bean seeds can be used for preparing herbal medicines for treating infertility.
- Convulsion Treatment: The pods of the African oil bean seeds can be used for treating convulsion. Smoke from burnt African oil bean leaves can also be used for treating convulsion.
- Induction of Abortion: African oil bean seeds can be crushed and mixed with red ants for inducing abortion.
- Treatment of Gonorrhea: The fruits, seeds, bark, and leaves of the African oil bean tree have been proven effective for tackling gonorrhea.
- Treatment of Fever: The leaves of the African oil bean tree can be decocted with bush pepper and taken for treating fever.
- Obesity Control: African oil bean plant is a rich source of phytoestrogens thus can be taken as a nutritional and vitamin supplement for controlling overweight and obesity.
How to Prepare Ugba (African Oil Bean Seed)
Preparing the African oil bean seeds before consumption requires cracking the shells to remove the seeds, which are then boiled in water between 14 to 18 hours after which the cooked seeds are sliced into thin strips, soaked in water, and washed severally before being wrapped in green leaves for three to four days for the fermentation process to take place. Once fermentation has taken place, the ugba can be used for preparing assorted mouthwatering dishes.
To minimize easy spoilage, processed ugba or ukpaka are usually tied up in airtight leaves, cellophane, or containers. They can equally be preserved in the freezer. Freshly sliced ukpaka seeds are usually grayish-white in color; however, they tend to change to dark brown color once fermentation has taken place.
Read also: Philadelphia Food Truck
Flow chart for the preparation of ugba (Odunfa and Oyeyiola, 1985)
Microorganisms involved in the fermentation
Several workers have investigated the microorganisms involved in the fermentation. Only bacteria are involved in the fermentation (Obeta, 1983; Odunfa and Oyeyiola, 1985; Ejiofor et al., 1987; Ogueke and Aririatu, 2004). The main fermenting microorganisms have been identified to be proteolytic Bacillus sp. (Obeta, 1983) which include B. subtilis (most predominant), B. licheniformis, B. megaterium, B. macerans and B. circulans.
Their numbers increased tremendously from 103 at the start of fermentation to 108 at the end of the fermentation (72 h). Other bacteria identified in the fermenting slices include coagulase negative Staphylococcus sp., Micococcus sp. (their numbers decreased after 72 h of fermentation), Leuconostoc mesenteroides; Lactobacillus plantarum, Streptococcus lactis, Proteus sp., Enterobacter sp. and E. coli. Some workers isolated the yeasts Candida tropicalis and Geotrichum candidum during fermentation (Ejiofor et al., 1987).
Dangers of the African Oil Bean Seed
Some studies reveal that unfermented African oil bean seeds contain traces of a poisonous alkaloid substance known as paucine. The seeds equally contain traces of a growth depressant known as caffeoylputrescine plus molds, which are capable of producing mycotoxins in foods. Interestingly, these toxic substances can be neutralized after cooking and fermenting the seeds.
