Chemical composition of cooked and uncooked sweet potato and its significance for human nutrition.
1989
Bradbury J.H.
The chemical composition of 164 samples of sweet potato from five countries of the South Pacific was determined. A wider range of nutrients was analyzed and where possible, results were compared. White fleshed cultivars from the South Pacific contained much less sugar and B-carotene than the yellow-fleshed varieties common in America. Edible leaf tips contained much larger amounts of moisture, protein, Fe, K, Mg, Vitamin A, riboflavin, and nicotinic acid and much less energy than tubers. Cooking of tubers caused considerable losses of thiamine, riboflavin, and nicotinic acid which are nutritionally important because of the small amounts of these vitamins present. There was also a decrease in starch and increase in maltose content of tubers upon cooking. The latter increase was not observed in cooking cassava, yam, or taro. Selection/breeding for improved chemical composition was discussed with particular reference to protein content which was found to be very variable (0.34-2.9%) and was low in a region subject to malnutrition. The nutritional aspects of tropical root crops (including sweet potato) were compared with representative tropical plant foods, rice, legumes, and edible green leaves. Root crops were found to be a good source of energy, an average source of minerals and vitamins, and the poorest source of protein.
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