Nutritional Value
| Nutritional value per 100 g (3.5 oz) | |
|---|---|
| Energy | 494 kJ (118 kcal) |
| Carbohydrates | 27.9 g |
| - Sugars | 0.5 g |
| - Dietary fiber | 4.1 g |
| Fat | 0.17 g |
| Protein | 1.5 g |
| Vitamin A equiv. | 7 μg (1%) |
| Thiamine (vit. B1) | 0.112 mg (10%) |
| Riboflavin (vit. B2) | 0.032 mg (3%) |
| Niacin (vit. B3) | 0.552 mg (4%) |
| Vitamin B6 | 0.3 mg (23%) |
| Vitamin C | 17.1 mg (21%) |
| Vitamin K | 2.3 μg (2%) |
| Calcium | 17 mg (2%) |
| Iron | 0.5 mg (4%) |
| Magnesium | 21 mg (6%) |
| Phosphorus | 55 mg (8%) |
| Potassium | 816 mg (17%) |
| Zinc | 0.24 mg (3%) |
| Percentages are relative to US recommendations for adults. |
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The protein content and quality of roots and tubers is lower than other food staples. Of all roots and tubers, the protein content of yam and potato is the highest, being approximately 2 percent on a fresh weight basis. Yams, with cassava, provide a much greater proportion of the protein intake in Africa, ranging from 6 percent in East and southern Africa to about 16 percent in humid West Africa.
Yam, like other root crops, is not a good source of essential amino acids. It is rich in phenylalanine and threonine but limiting in the sulphur amino-acids, cystine and methionine and in tryptophan. Yam consuming areas of Africa have a high incidence of kwashiorkor, a serious medical condition in children caused by protein deficiency. Experts emphasize the need to supplement a yam-driven diet with more protein-rich foods in order to support active and healthy growth in infants.
Except for potassium, vitamin B6 and vitamin C, yam is a food with low nutrient density.
Yam provides around 110 calories per 100 grams. Yam is high in vitamins C and B6, potassium, manganese and dietary fiber while being low in saturated fat and sodium. A product that is high in potassium and low in sodium is likely to produce a good potassium-sodium balance in the human body, and so protects against osteoporosis and heart disease.
Yam products generally have a lower glycemic index than potato products.
The African yam (Dioscorea sp) contains thiocyanate which was implicated by one author as potentially important in sickle cell anemia, an effect that remains scientifically unsubstantiated.
- Nutritional significance of yam
Yam's importance in the diet of the people in Nigeria and West African countries cannot be overemphasized. It contributes more than 200 calorie per person per day for more than 150 million people in West Africa while servicing as an important source of income to the people. Yam is an attractive crop in poor farms with limited resources. It is rich in starch, and allows many recipes. Yam is also available all year round making it preferable to other unreliable seasonal crops. These characteristics make yam a preferred food and a culturally important food security crop in some sub-Saharan African countries.
Read more about this topic: Yam (vegetable)