Diversity in proximate analysis of tubers of some African yam bean (<i>Sphenostylis stenocarpa</i>) (Hochst Ex. A. Rich.) Harms (Fabaceae) accessions

Abstract

This study was carried out to determine the proximate and mineral composition of fresh tubers of 17 African Yam Bean (AYB) accessions. Standard analytical procedures were adopted in the determination of bioactive compounds in the tubers of the different accessions. Data were subjected to descriptive statistics, principal component and clustering analysis. Ash content ranged between 4.59-9.99%, Carbohydrate (46.59-66.52%), Crude fibre (6.93-12.13), Fat (1.06-4.04%), Moisture content ranged between 11.36-21.91% and Protein (4.91-14.50%). The range of mineral content evaluated were: Calcium (1.53-5.82), Copper (10.59-44.93), Iron (63.52-240.48), Magnesium (0.59-2.26), Manganese (42.25-160.01), Nitrogen (0.75-2.23%), Potassium (1.34-5.08), Sodium (0.05-0.22) and Zinc (28.24-106.93. The proximate variables in the tubers significantly (P<0.05) distinguished the 17 AYB accessions. Three distinct clusters were visible. The seven accessions in cluster I had the highest protein, carbohydrate and moisture content. Cluster II had the least mineral content. Accessions with the highest fat and mineral content were grouped in cluster III. Food, nutritional and medicinal values inherent in AYB tubers is high and promising, its utilization in human and livestock feeds is greatly encourage.

Keywords: Accessions, African yam bean, diversity, proximate analysis, tubers