The effects of storage (4 months) on the chemical composition of yam tubers and its relation to textural quality of a major yam food product (pounded yam) were studied using six varieties of Dioscorea rotundata and D. alata. Chemical composition of both freshly harvested tubers and those stored for 4 months were determined by standard methods of analysis. Sugar, nonstarchy carbohydrate and dry matter contents of the tubers increased during storage while the starch, fat and protein contents decreased. Pounded yam made from stored yam tubers were of better textural quality than those from freshly harvested ones. Storage of yam tubers could be an effective way of improving the textural quality of pounded yam. This is important for processing yam tubers into value-added products.


The results of this research provide a scientific basis for differences in the food quality of food products made from freshly harvested and stored yam tubers. Storage is important to the industrial processing of value-added products (e.g., instant yam flour, yam flakes) from yam tubers. This study will help processors in selecting appropriate raw materials that will give optimal food quality that is expected and will be accepted by consumers.