Sweet potatoes already enjoy a reputation as an extremely high source of fiber and antioxidants. Now, though, scientists have found that a simple, inexpensive treatment with an electric current boosts its polyphenols, phytonutrients that help the body fight disease.
Initially, researchers in Japan discovered that passing an electric current through white potatoes increases their polyphenol by 60 percent. Naturally found in fruits and vegetables, polyphenols help ward off disease and reduce the effects of aging. After their success with white potatoes, researchers zapped sweet potatoes.
The researchers electrified the vegetables by placing them in a salt solution that conducts electricity and passing varying amounts of electric current through the solution for five minutes. They found 0.2 amps of current to be optimal in increasing antioxidant activity in the sweet potatoes. The treated sweet potatoes had 1.4 times the antioxidant benefits of those left untreated.
The scientists note that the method represents an inexpensive and easy way to increase the health benefits of an already healthy food without altering flavor.
Sweet potatoes already contain seven times more polyphenols than other potatoes. The Center for Science in the Public Interest at one point named the sweet starch as the No. 1 nutritional vegetable when eaten baked.
When you cook sweet potatoes, you can retain the heightened antioxidant most effectively by steaming them.