Wednesday, August 1, 2012

Sweet potato nutrition facts


Sweet potato nutrition facts

Sweet potato, not only is just sweet to your taste buds but also good for your cardiovascular health. This starchy root vegetable is rich source of flavonoid anti-oxidants, vitamins, minerals, and dietary fiber that are essential for optimal health. Botanically, this tuber belongs to the family of Convolvulaceae, and named botanically as Ipomoea batatas. It is grown throughout the tropical and warm temperate regions. The crop requires just sufficient water and attention for their cultivation. The tuberous root has oblong/elongated shape with tapering ends and has smooth outer skin whose color ranges from red, purple, brown, and white, depending up on the variety.          
                            

Sweet potatoes should not be confused with yams, another starchy root commonly grown in Western Africa. Yams are indeed larger in size that can grow up to 120 pounds in weight and up to 2 meters in length. Yams are the tropical crops and never grow where the temperature dips below 68 degrees F. Important differentiating features that distinguish sweet potatoes from yams are:
  • Sweet potatoes (Ipomoea batatas) are dicotyledonous, relatively smaller and possess very thin peel.
  • Whereas, yams are monocotyledons, larger, features thick, rough, dark brown to pink skin depending up on cultivar type.
Internally, it has starchy flesh which, depending upon the pigments concentration, ranges from white through yellow, orange, and purple.
Boniatos, also known as Cuban sweet potatoes, feature dry, starchy flesh underneath the reddish brown skin. They have mildly sweet flavor and coked in a similar way like potatoes.
Sweet potato leaves (top greens) are also edible; in fact, the greens contain more nutrients and dietary fiber than some green leafy vegetables like spinach (for example, 100 g sweet potato leaves provide 1028 IU of vitamin A).

Health benefits of Sweet potato

  • Sweet potato is one of the average calorie starch food (provide just 90 cal/100 g vs 70 calories/100 g of potato). The tuber, however, contains no saturated fats or cholesterol; but is rich source of dietary fiber, anti-oxidants, vitamins, and minerals.
  • Its calorie content mainly comes from starch, a complex carbohydrate. Starch raises the blood sugar levels slowly on comparison to simple sugars and therefore, recommended as a healthy food supplement even in diabetes.
  • The tuber is excellent source of flavonoid phenolic compounds such as beta-carotene and vitamin A(100 g tuber provides 14187 IU of vitamin A and 8509 mcg of β-carotene). The value is one of the highest among root vegetables category. These compounds are powerful natural antioxidants. Vitamin A is also required by the body to maintain integrity of healthy mucus membranes and skin. It is also vital nutrient for vision. Consumption of natural vegetables and fruits rich in flavonoids helps to protect from lung and oral cavity cancers.
  • The tubers are packed with many essential vitamins such as pantothenic acid (vitamin B-5),pyridoxine (vitamin B-6), and thiamin (vitamin B-1), niacin, and riboflavin. These vitamins are essential in the sense that body requires them from external sources to replenish. These vitamins function as co-factors for various enzymes during metabolism.
  • Sweet potato provides good amount of vital minerals such as iron, calcium, magnesium, manganese, and potassium that are very essential for enzyme, protein, and carbohydrate metabolism.
  • Sweet potato leaves are indeed more nutritious than tuber. Weight per weight, 100 g of fresh leaves contain more iron, vitamin C, folates, vitamin K, and potassium but less sodium than the tuber.
See the table below for in depth analysis of nutrients:

Sweet potatoes (Ipomoea batatas), raw,
Nutrition value per 100 g.
(Source: USDA National Nutrient data base)
PrincipleNutrient ValuePercentage of RDA
Energy86 Kcal4%
Carbohydrates20.12 g15.5%
Protein1.6 g3%
Total Fat0.05 g<0.5%
Cholesterol0 mg0%
Dietary Fiber3 g8%
Vitamins
Folates11 µg 3%
Niacin0.557 mg3.5%
Pantothenic acid0.80 mg16%
Pyridoxine0.209 mg15%
Riboflavin0.061 mg5.5%
Thiamin0.078 mg6.5%
Vitamin A14187 IU473%
Vitamin C2.4 mg4%
Vitamin E0.26 mg2%
Vitamin K1.8 µg 1.5%
Electrolytes
Sodium55 mg3.5%
Potassium337 mg7%
Minerals
Calcium30 mg3%
Iron0.61 mg7.5%
Magnesium25 mg6%
Manganese0.258 mg11%
Phosphorus47 mg7%
Zinc0.30 mg3%
Phyto-nutrients
Carotene-α7 µg --
Carotene-ß8509 µg --
Crypto-xanthin-ß0 µg --

Selection and storage

Although sweet potato leaves are being eaten in some parts of the world, the root that is the toast of sweet potato lovers. In the store, buy fresh tubers with intact smooth skin and firm to woody consistency. Go for organic varieties for best taste and nutrition levels.
Avoid soft, flabby, or wilted roots. In addition, sprouting make them loose flavor.
Wash them in clean running water to remove sand and soil. They should be stored in a cool, dark, and well-ventilated place.

Preparation and serving methods

To prepare, wash the root in cold water. It can be eaten raw with skin. However, for baking preparations, its skin may be peeled off before or after cooked.

Here are some serving tips:
  • Fresh sweet potatoes can be eaten raw.
  • Baking in water with a pinch of salt would give rich taste to them. Peel off the skin before eating.
  • Camote, sweet potato known in the Latin world, is used extensively in the Mexican cuisine.
  • Camote cue, where in the tuber deep fried and caramelized with brown sugar, is a popular street food in the Philippines.
  • It sweet flesh used in soups, curries, stews, and in confectionary to make cakes, pie...etc.
  • The tuber also used to prepare different kinds of baby foods.
  • Sweet potato chips are enjoyed as favorite snacks.

Safety profile

Sweet potatoes contain oxalic acid, a naturally occurring substance found in some vegetables that may crystallize as oxalate stones in the urinary tract in some people.
It is, therefore, individuals with known history of oxalate urinary tract stones may have to avoid eating them. Adequate intake of water is therefore advised to maintain normal urine output in these individuals to minimize stone risk.

No comments: