Nutrient Composition and Functional Properties of Major Cultivars of Aerial Yam (Dioscorea bulbifera) in Nigeria

Abstract

Flour from three major cultivars (white, purple and yellow) of aerial yam (Dioscorea bulbifera) in South-East Nigeria were analyzed and compared in terms of their nutrient and functional properties. The results of the proximate analysis showed that flour from the yellow cultivar had the highest protein value of 6.27% while the white cultivar produced flour with the lowest protein content of 4.92%.  The three cultivars had relatively low values for ash, fat and crude fibre. Though the yellow cultivar flour had the highest ash and fat content values of 2.67% and 0.98% respectively; the white cultivar flour recorded the highest crude fibre value  of 1.17%. The proximate results also revealed moisture content range of 6.99 – 7.12% for all the three cultivars of aerial yam. The result of the antinutritional factors determined (tannin, phytate, alkaloids, oxlate, flavonoid) were low and falls within acceptable limits for consumption. The flour samples recorded bulk density values of 0.60g/cm³ (purple cultivar), 0.62 g/cm³ (white cultivar) and 0.63 g/cm³ (yellow cultivar). The swelling capacity of the flour samples  were higher in the yellow cultivar (1.56%) while the least swelling power was recorded by the purple cultivar (1.25%). The three major cultivars (white, purple and yellow) of aerial yam have great potential for use in different food product development.

Keywords: aerial yam, nutrient, functional properties