Boosting Antioxidants in Sweet Potatoes
Kazunori Hironaka, Ph.D. and colleagues at the University of the Ryukyus, Nishihara, Okinawa, Japan reported at the 244th National Meeting & Exposition of the American Chemical Society about an inexpensive way to increase the antioxidant content of sweet potatoes. Sweet, white potatoes are a dietary staple in developing countries, where malnutrition is a common problem. It has been considered a healthy food, with its complex carbohydrates, vitamins A and C, iron, calcium and fiber content. Aside from these, it contains antioxidants called polyphenols, a family of chemical compounds found in fruits and vegetables that may help protect against diseases and the effects of aging.
In their study, Hironaka and colleagues placed sweet potatoes into a salt solution that conducts electricity, and then passed various amounts of electric current through the water and the potatoes for 5 minutes. The use of 0.2 amps of current produced the best results, which boosted antioxidant activity in the potatoes by 1.4 times and increased total polyphenol content by 1.6 times compared to untreated potatoes. The researchers explain that the electric current apparently stresses the potatoes, which produce more polyphenols as a protective measure.
Hironka notes that while steaming is the best method of cooking potatoes to retain their antioxidant activity, passing an electric current to the cooking water can enhance their health benefits and has no effect on flavor. He believes that it is also an inexpensive and simple way to improve people’s nutrition and health while relieving hunger.
American Chemical Society. Electrifying success in raising antioxidant levels in sweet potatoes. ScienceDaily. Retrieved August 23, 2012.