Project Abstract

Abstract
African yam bean (Sphenostylis stenocarpa) is a leguminous crop that is underutilized despite its nutritional potential. This study aimed to investigate the influence of different processing methods on the protein and cyanide content of African yam bean. Three processing methods, namely soaking, boiling, and roasting, were employed, and their effects on the protein content and cyanide levels were analyzed. The results showed that the protein content of African yam bean increased significantly after processing. The soaking method led to the highest increase in protein content, followed by boiling and roasting. This increase in protein content could be attributed to the breakdown of anti-nutritional factors and cellular structures during processing, making the protein more accessible and available for digestion. In terms of cyanide content, all three processing methods led to a reduction in cyanide levels. Cyanide is a toxic compound present in many plant foods, including African yam bean, and its reduction is essential to enhance the safety and palatability of the crop. The soaking method was the most effective in reducing cyanide content, followed by boiling and roasting. This reduction in cyanide levels could be attributed to leaching during soaking and boiling, as well as degradation at high temperatures during roasting. Overall, the findings of this study demonstrate that processing methods have a significant influence on the protein and cyanide content of African yam bean. The increase in protein content after processing highlights the potential of this underutilized crop as a source of plant-based protein. Moreover, the reduction in cyanide levels through processing methods enhances the safety and acceptability of African yam bean as a food source. These results have important implications for the utilization of African yam bean in food and feed applications. By understanding the effects of processing methods on the nutritional and anti-nutritional components of African yam bean, strategies can be developed to promote its consumption and utilization in diverse food products. Further research is warranted to explore additional processing methods and optimize conditions to further enhance the nutritional quality of African yam bean.

Project Overview

INTRODUCTION

African yam bean (Sphenostylis stenocarpa) belongs to the genera papilliona sec which is in the class known as Leguminousae (Okigbo, 1973). It is one of the neglected indigenous grain legumes in Nigeria. It is produced mostly in the eastern part of the country where it is consumed in different forms such as snacks, delicacy, man meal etc. It can be used for the fortification of other foods (Eke, 1997)
In Nigeria, it has as many names as there are communities cultivating it. Some of the names are Okpdudu, Azam, Uzuaku, Ijiriji, Azara, Ahaja, Nzamiri, Odudu, Girigiri (Hausa), sese (Yoruba) and Nsana (Ibibio) (Ogbo, 2002).
The high protein content of African yam bean makes it an important source of protein in the diets of population groups of many tropical countries (Kon, 1979, Ekpen young and Borchers, 1980). In addition, the high protein bean flour fractions could be substituted for wheat flour to produce acceptable qualities of cookies breads and leavened doughs (Uebersax and Zabik, 1986; Nzereogu, 1993).
It may also be consumed as porridge after cooking. The mature dry seeds can be used to prepare “moi – moi” and “akara” (Ezueh, 1973; Akoma, 1996). The African yam bean apart from being rich in protein also contains carbohydrate, fat and minerals (NAS, 1979).
A major constraint in the utilization of African yam bean is the different dehulling method. Traditionally, the dehulling method involves manual removal of the hulls from the individual soaked seeds. This method is quite laborous (labour intensive), time – consuming and does not favour effective utilization of the bean. It is widely believed that under cooked African yam bean seeds cause diarrhoea and over cooked seeds cause constipation (Asusu and Undie, 1986).
Previous works showed that steeping will among other things improve the dehulling characteristic of the African yam bean while maintaining the nutritional quality viz: invitro protein digestibility and also improving the functional properties when processed into flour (Abbey and Berezi, 1988). It is evident that better processing methods will not only enhance the acceptability and utilization of this legume but will also improve the nutritional status of the consuming populace (Uebersax et al, 1989).
The overall objective of this study is to investigate the various processing methods and their effects on the protein and cyanide content of African yam bean in conclusion, before the commencement of any research or project, there is meant to be aim/aims of such research.
As such, the aims of this study include:-
1. To determine the hydrogen cyanide content of the flour.
2. To analyse for the crude protein content of the flour.
3. To determine some of the functional properties of the flour.
4. Determination of the chemical composition of the flour.
5. To determine the bulk density of the flour.