Nutritional quality of yam (Dioscorea dumetorum and D rotundata) flours for growing rats

The digestibility and metabolism of diets based on flours prepared from raw, boiled or steamed tubers of the sweet yam (Dioscorea dumetorum) were evaluated in growing albino rats by the balance method in comparison with diets containing similar flours from the popular white yam (D rotundata). The results show that whatever their method of preparation, flours from D dumetorum promote higher growth rate and have higher nutritional value in the growing rat than corresponding D rotundata flours. This can be attributed to the good digestibility of D dumetorum starch which facilitates digestibility and absorption of nitrogen and other nutrients. Moisture‐heat treatment of tubers before processing into flour improves the nutritional value, especially for D rotundata.