Food Science and Technology Project Topics

Proximate and Sensory Characteristics of Akara Produced From Different Blends of African Yam Bean and Cowpea

Proximate and Sensory Characteristics of Akara Produced From Different Blends of African Yam Bean and Cowpea

Proximate and Sensory Characteristics of Akara Produced From Different Blends of African Yam Bean and Cowpea

Chapter One 

The Objective of the Study

Therefore the objective of this study  was  to  produce  Akara from  the blends of  African  yam  bean and  cowpea and  to  evaluate  proximate composition and sensory characteristics  on the  substitution levels of the two blends with the aim of promoting the utilization of African yam bean.



Legumes in Human Nutrition

According to National Academy of Science (NAS) (1997), a legume is a simple dry fruit that develops from simple carpel and usually opens along a seam on two sides. Grain legumes are plants belonging to the legume family with papilionaceous flowers and pods containing seeds. Most legumes do not need industrial fertilizers this is because of their natural symbiosis with Rhizobium which provides them with organic proteins made directly from atmospheric nitrogen (NAS, 1997). Grain legumes are cultivated primarily for their seeds which are rich in energy and protein. Legumes are seeds that grow in pods; they are high in fibre, low in fat and a good source of protein. Beans, lentils, peas, soybeans, and peanuts are all examples of some major common legumes. Lesser known legumes are African yam beans, baobab among others (ObiakorandNwanekezi, 2008). A legume is a simple dry fruit that develops from a simple carpel and usually opens on two sides. The seeds are hard and dried and cannot be eaten unless prepared in the kitchen. For quite some time, legumes were considered a rather lowly food; their food is increasing with recent discoveries concerning their many nutritional and health properties (Pamplona-Roger, 2006).

Crosby (2009) stated that the plants show great diversity in both vegetative and floral form; woody, perennial species predominate, but numerous herbaceous forms and even a few aquatics also occur. The fruit is the feature by which the family is best characterized. Technically known as a legume, it is a single-chambered, flattened seedpod with two sutures. It usually splits open along the two sutures, as in the common pea. The seeds are attached along one of the sutures. The legume may be indehiscent (not splitting), as in the peanut, which matures underground; or explosively dehiscent, as in broom or lupine. It also may range from only a few millimeters long to more than 30 cm (more than 12 in) and may be single or many seeded and brightly or dully colored.

According to Crosby (2009) the family of legume is divided into three closely related subfamilies, which are often treated as three separate families. One subfamily is mostly herbaceous and is characterized by simple leaves and highly irregular flowers with ten stamens in two clusters. About 12,000 species exist, including such plants as peas, beans, peanuts, and soybeans; clover and alfalfa; and sweet pea, broom, and lupine. The second subfamily contains mostly trees and shrubs and is characterized by bipinnately compound (doubly branching) leaves and regular (radially symmetrical) flowers with ten or more stamens extending beyond the petals. This subfamily contains about 3,000 species and includes acacias and mimosas. The third subfamily is also mostly woody, but with leaves pinnately compound, and slightly too highly irregular flowers with ten stamens in one cluster. This subfamily contains about 3,000 species and includes such plants as brazil wood, carob, honey locust, Judas tree, logwood, and tamar (Crosby, 2009).

Bean as a Legume

According to Microsoft Encarta (2009) most beans belong to the subfamily Papilionoideae of the family Fabaceae and bean is common name widely applied to many plants of the legume family. The seeds and pods of these plants are used for food and forage.The seeds themselves are also called beans and are valuable as food because of their high protein content. The term bean is also applied to plants of other families, such as the Indian bean, which is a North American species, and the sacred bean, or Indian lotus. The seeds or fruits of certain other plants, such as the coffee tree and the castor-oil plant are also called beans.

African yam bean (AYB) (Sphenostylisstenocarpa)

African yam bean is known and called different names by different tribes in Nigeria, some of the names are Azama, Ijiriji, Azam, and Uzaaki in Igbo; Girigiri in Hausa; Akpaka in Delta and Nsama in Ibibio. Other names are Okpodudu, Ahaja, Nzamiri, Odudu and Igala. In some parts of Ghana, it is called Kulege or Kutreku. African yam bean belong to the family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Phaseoleaesubtribe: Phaseolinae.,also placed in: Papilionaceae. It is also called yam pea in English and it is usually cultivated in the following African regions Northeast Tropical Africa: Chad; Ethiopia East Tropical Africa: Kenya; Tanzania; Uganda, West-Central Tropical Africa: Burundi; Central Africa Republic; Zaire West Tropical Africa: Cote D’Ivoire; Ghana; Guinea; Mali; Niger; Nigeria; Togo South Tropical Africa: Angola; Malawi; Zambia; Zimbabwe (USDA, 2007).

African yam bean is grown both for its edible seeds and its tubers (Kluet al., 2001). The seeds are mostly used in some regions. It is a vigorous vine which twines and climbs to heights of about 3m and requires staking, with its prolific spattering of large flowers which may be pink, purple, or greenish with white, making it an attractive ornamental (NAS, 2009). The slightly woody pod which contains 20 to 30 seeds is up to 30cm long and mature within 170 days (Kluet al.,2001). The seeds of African yam bean vary in sizes and shapes. The seed coat has a range of colors from pale white to black with spotted or mottled grey, cream and brown in between. In Nigeria, it is grown mostly in the northern part where it is grown mainly for its seed (Alozieet al., 2009).

Distribution of African Yam Beans

Sphenostylisstenocarpa is native to tropical west and central Africa and is cultivated in southern and eastern Africa (Ecoport, 2009). Both wild and cultivated types now occur in tropical Africa as far south as Zimbabwe, throughout West Africa from Guinea to southern Nigeria. It thrives on deep, loose sandy and loamy soils with good organic content and good drainage. It grows better in regions where annual rainfalls range between 800-1400mm and where temperatures are between 19-27°C (Ecoport, 2009). The plant flowers after 90days and the pods mature in 140 to 210days. The tubers are ready to harvest 150 to 240days after sowing.





African yam bean (Spenostylis stenocarpa) seeds were purchased from the local market in Owo, Ondo state.  Cowpea (Vignaungiuculata) was also purchased from Ekeonuwa market in Imo state. Other ingredients such as groundnut oil, onions, red pepper, salt and maggi were all gotten from Oja Oba market, in Owo, Ondo State.


 Sample Preparation

African  yam  bean  (AYB)  and  cowpea  seeds were  sorted  to  remove  extraneous materials and damaged seeds.




Table 4.1: Proximate Composition of “Akara”Produced from the Blends of Cowpea and AYB





The results of proximate analysis of the samples showed that samples produced from cowpea and African yam bean blends were not of better nutritional quality than the control sample, although the proximate properties proof that whole cowpea is still better than the mixture. Based on the results of sensory evaluation of akara samples produce with different pastes, it can be concluded that there was no significant difference except in sample C80A20, in terms of quality and acceptability, between the different samples up to 30% Africa yam beansubstitution. This is expected to increase the domestic utilization of African yam bean and possibly an improvement on the nutritional quality of “Akara”.


Based on the above, it is therefore recommended that African yam bean can be used to partially substitute cowpea in “Akara” preparation. Steeping of AYB in sodium bicarbonate can help to reduce the beany off flavor more than the ones soaked with water only; and produced more acceptable “Akara” than the latter. The use of AYB (sphenostylissternocarp) as a partial substitute in the production of “Akara”should be acceptable, up to certain levels and is obviously cheaper than using 100% cowpea. The different conditions utilized in the pre-treatment of the AYB seeds should be optimized in order to promote the acceptability of AYB as a substitute for the production of “Akara” (bean ball). Also incentives should be given to farmers so that they can cultivate more AYB and distribute them to other areas effectively.


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