potato - Info and its antioxidant profile
Info and its antioxidant profile
Now there's one more good reason to eat potatoes. The U.S. Department of Agriculture recently included potatoes on its list of the top 20 most antioxidant-rich foods. The list included the Russet potato, the most common variety consumed by Americans. Further research by scientists in the potato industry indicates that potatoes of color, particularly red- and purple-skinned varieties and yellow- flesh potatoes like Yukon Golds, contain high levels of antioxidants as well.
"The presence of antioxidants is the latest surprising fact about potato nutrition," says Katherine Beals, phD, RD, FACSM and consultant to the U.S. potato Board (USpB). "people should be excited to learn this good news about a favorite food, beyond that a 5.3-ounce potato with skin is an excellent source of potassium and a good source of fiber for 100 calories. potatoes contain no fat, cholesterol or sodium."
The term "antioxidants" covers a class of compounds that work in the body to clean up waste products called "free radicals" that are produced when cells react with oxygen, a process called oxidation. Oxidation is a natural part of aging, but it can result in chronic diseases. Thus, it's helpful to keep free radicals in check.
Vitamin C is hailed as the most potent antioxidant found in potatoes. One medium-sized potato packs 27 mg or 45 percent of the Daily Value for Vitamin C -- a formidable amount that can contribute significantly to total daily intake. Vitamin C is a powerful antioxidant that protects your body's cells. It also helps keep gums healthy and can protect the body from infection by keeping the immune system strong.
Other types of antioxidants found in potatoes include plant compounds, known as phytochemicals, that are responsible for the color in many fruits and vegetables. Examples are carotenoids, which give yellow or orange colors to foods, and anthocyanins, which provide purple and red colors.
-- Additional Research on potatoes and Antioxidants --
Research by scientists in the potato industry continues to examine ways to increase the antioxidant content of potato varieties.
"There are several exciting studies underway on antioxidants and potatoes -- some are showing encouraging results for potatoes already in the marketplace, and others are exploring the creation of new cultivars that will maximize the antioxidant attributes of potatoes," explains Dr. Beals. "It's an area we're tracking closely along with researchers in the field."
In a recent study published in the American Journal of potato Research (2004), Charles R. Brown and colleagues demonstrated that white flesh potatoes had approximately 50 micrograms of carotenoids in a 100 g serving, light yellow-flesh potatoes had about three times as much, while brilliant yellow- and orange- flesh potatoes contained upwards to 16 times this amount. In another study published this year, researchers from the Texas potato Variety program at Texas A&M University reported results after screening over 320 specialty potatoes for carotenoid content. They found that a particular breed of red-skinned, yellow-flesh potatoes had the highest amount of carotenoids followed by purple-flesh, purple-skinned potatoes.
Research indicates that while white flesh potato cultivars rate similar to published reports for tomatoes and carrots as having a low antioxidant potential, red and purple fleshed potatoes rate about three to eight times higher (average Oxygen Radical Absorbance Capacity (ORAC) value of 354 mg); ranking them equivalent to sweet potatoes, spinach, and Brussels sprouts.
In addition, research has indicated that potatoes can be bred to contain higher levels of antioxidants. In a 2004 study published in the Journal of Agriculture and Food Chemistry, Marcin Lukaszewicz and others successfully genetically altered potatoes to produce species with higher phenolic contents. The flavinoid-enriched potatoes showed improved antioxidant capacity.
Additional research is currently underway and being conducted in universities nationwide and in other countries, including the United Kingdom, Scotland, Germany, Korea, and poland.
-- potatoes: A Nutrition powerhouse --
It's reassuring to know that a true comfort food, the potato, that also contributes antioxidants such as vitamin C, is fat-free and a good source of fiber. One serving of skin-on potatoes (5.3- ounces) also contains 720 mg of potassium, making it an excellent source of potassium. As Americans strive to consume low-fat diets rich in fruits and vegetables to help reduce the risk of some types of cancer, they'll be happy to know the potatoes they already love are good for them too.