Japanese Sweet Potato Nutrition
The Japanese sweet potato is a red- or purple-skinned, yellow-white fleshed potato that belongs to the Ipomea batata botanical family. According to Herbal Extracts Plus, the Japanese sweet potato is similar to American yams, but tastes sweeter. Vietnam, China, Japan, India and Indonesia are the biggest producers of Japanese sweet potatoes. It is commonly used in Asia as a thickener and flour substitute, as well as a main ingredient in the Japanese dish tempura and in the liquor shochu. Japanese sweet potatoes are a good source of dietary fiber and provide a number of essential vitamins and minerals.
Calories and Fat
According to the USDA Agricultural Research Service Nutrient Data Laboratory, an average-sized raw Japanese sweet potato -- approximately 5 inches long and weighing 130 grams -- contains about 113 calories. None of these calories are provided by fat. Sweet potatoes contain no fat, saturated fat or cholesterol.
Japanese sweet potatoes contain approximately 27 grams of carbohydrates. This carbohydrate value comes from three sources: dietary fiber, sugars and starch. Japanese sweet potatoes contain approximately 4 grams of dietary fiber, providing about 16 percent of the daily value for fiber. The 5 grams of sugars in Japanese sweet potatoes are predominantly sucrose and glucose, with a small amount of fructose. The USDA reports that the potatoes contain about 17 grams of starch.
Japanese sweet potatoes provide approximately 2 grams of protein. While trace amounts of all essential amino acids are present, the potatoes contain the compounds threonine, leucine, phenylalanine, valine, alanine and serine in the largest amounts.
Japanese sweet potatoes are a rich source of a variety of vitamins essential for optimum health, including vitamins A, C, E and B-6. According to the USDA, Japanese sweet potatoes contain 11,062 micrograms of vitamin A, providing 202.2 percent of daily value. One average-sized sweet potato provides 30 percent of the DV for vitamin C and about 12 percent of the vitamin B-6 requirement. These vitamins are thought to act as powerful antioxidants, preventing cellular damage from free radicals in the body.
Potassium, calcium, sodium, phosphorus, manganese, copper, iron and magnesium are all minerals that Japanese sweet potatoes contain in large amounts. With 438 milligrams of potassium in every average-sized potato, Japanese sweet potatoes provide nearly 10 percent of the daily requirement. They provide 25 percent of the daily requirement for manganese, and about 12 percent of the copper requirement.
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