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Electrifying tubers

New ways of boosting healthful antioxidant levels in potatoes


September 16, 2010
By Fruit & Vegetable

Topics

Here’s a scientific discovery fit to give Mr. Potato Head static cling
and flyaway hair (if the vintage plastic toy had hair). Scientists have
discovered two simple, inexpensive ways of boosting the amounts of
healthful antioxidant substances in potatoes.

Here’s a scientific discovery fit to give Mr. Potato Head static cling and flyaway hair (if the vintage plastic toy had hair). Scientists have discovered two simple, inexpensive ways of boosting the amounts of healthful antioxidant substances in potatoes. One involves giving potatoes an electric shock, and the other involves zapping them with ultrasound – high-frequency sound waves.

tubers 
Scientists are treating potatoes with ultrasound and electric current to increase their antioxidant content.  Contributed photo

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“We found that treating the potatoes with ultrasound or electricity for five to 30 minutes increased the amounts of antioxidants – including phenols and chlorogenic acid – by as much as 50 per cent,” said Kazunori Hironaka, PhD, who headed the research. “Antioxidants found in fruits and vegetables are considered to be of nutritional importance in the prevention of chronic diseases, such as cardiovascular disease, various cancers, diabetes, and neurological diseases.”

Hironaka, who is with Obihiro University in Hokkaido, Japan, indicated that the process could have widespread commercial application, due to growing consumer interest in “functional foods.” Such foods may promote overall good health, for instance, or reduce the risk of specific diseases. Hironaka estimated that sales of such products in the United States alone now approach $20 billion annually.

“We knew from research done in the past that drought, bruising and other stresses could stimulate the accumulation of beneficial phenolic compounds in fresh produce,” Hironaka explained. “We found that there hasn’t been any research on the healthful effects of using mechanical processes to stress vegetables. So we decided in this study to evaluate effect of ultrasound and electric treatments on polyphenols and other antioxidants in potatoes.”

The ultrasound treatment consisted of immersing whole potatoes in water and subjecting them to ultrasound for five or 10 minutes. For the electrical treatment, the scientists immersed potatoes in a salt solution for 10 seconds, and subsequently treated the tubers with a small electrical charge for 10, 20, and 30 minutes. The study team then measured antioxidant activity and the phenolic content and concluded that the stresses increased the amount of these compounds. The five minutes of ultrasound, for instance, increased polyphenol levels by 1.2 times and other antioxidants by about 1.6 times.

The research was presented during the 240th National Meeting of the American Chemical Society (ACS).