Nutritional and biochemical composition of D. alata (Dioscorea spp.) tubers

Abstract

The nutrition of the people of developing countries is a major public health issue which has challenged breeders to enhance the nutritional quality of preferred and staple crops such as yam. This study was therefore aimed at investigating the chemical and nutritional composition of 16 D. alata varieties. Dry matter content ranged from 22.3 to 33.8% on a fresh weight basis with corresponding moisture content between 66.2 and 77.7%. The ranges of crude protein, ash, sugar, starch and total dietary fibre were 4.3-8.7, 2.9-4.1, 3.6-11.0, 60.3-74.4 and 4.1-11.0%, on dry weight basis, respectively. The ranges of minerals in mg per kg (dry weight) were P 878-1900, Ca 260-410, Mg 390-580, K 10,550-20,100, Na 84-131, Mn 4.822.1, Cu 12.3-15.7 and Zn 10.1-14.1. The results indicate that D. alata varieties could be good sources of nutrients to its consumers and could also be very useful in nutritional applications and diet formulations. Highly significant variations (P<0.05) were observed among the varieties which suggest the potential for improvement through breeding programmes in promising varieties.