Giving potatoes a good soak in a salt water solution doesn’t seem that unusual. But dunking them in such a bath and then zapping them with a jolt of electricity is hardly a conventional culinary trick—even in the name of molecular gastronomy.
But that’s exactly what researchers at Obihiro University in Hokkaido, Japan did in an effort to give the spuds more nutritional punch. Dunking potatoes in salt water can make crispier French fries — the salt pulls out the tuber’s moisture, leaving behind the starch that gets nice and crunchy when it’s fried. Now the Japanese scientists report that electrifying potatoes, or even subjecting them to a few minutes of the high frequency sound waves from ultrasound, can boost the tubers’ antioxidant levels by as much as 50%.
The experiment that Kazunori Hironaka and his team conducted resembled a high school science project—in one, potatoes were placed in a tiny well, bathed in water and then subjected to ultrasound for five or 10 minutes. In another study, the potatoes were immersed in a salt water solution and then hooked up with electrodes to receive electrical jolts for 10, 20 and 30 minutes. Compared to untouched potatoes, those subjected to ultrasound showed 50% more antioxidants, and those treated with electrical current showed 60% greater antioxidant activity.
Antioxidants occur naturally in fruits, vegetables, nuts and grains and can counter the effects of free radicals that break down tissues and contribute to heart disease or cancer. All potatoes contain some carotenoids, which are a rich source of antioxidants, but the white potatoes common in the US—as compared to the yellow, red and purple varieties more popular elsewhere—likely posses the lowest levels of these compounds. Boosting those levels, says Hironaka, could make potatoes a far more nutritious and “functional” food.
But why send currents of electricity coursing through a tuber? Potato plants under stress in the environment, says Hironaka, such as from drought, physical trauma and climate changes, defensively pump out more antioxidant phenols and chlorogenic acid to ward off the damage these assaults can cause on tissues. The electricity and ultrasound waves are a lab-based way to mimic that stress.
But even he isn’t advocating setting up electrodes on the kitchen counter quite yet. Before that can happen, researchers need to better understand the way that currents and ultrasound change the characteristics of potatoes. That could one day help growers and manufactures make more out of a potato than French fries.
