Published on 02/28/01

A Sweet Change for Potatoes

Throughout the South, the humble sweet potato is a staple of regional cookery: Baked into soufflés, pies and casseroles, it flavors many a meal.

Yet that very distinctive flavor -- its cloyingly sweet taste -- also has been a major obstacle to its expansion as a crop around the world.

Deserted Island Food

"It's just hard to eat in significant amounts, day after day," said UGA horticulture professor Stanley Kays.

But thanks to research by Kays and fellow horticulture professor Wayne McLaurin, the sweet potato could overcome its own sweet taste to become a major world food source.

"If you were stranded on a deserted island and could have just one food to grow, this would be the one to pick," Kays said. "There are just so many pluses to it. It has an exceptionally high yield, it can be grown in a wide range of places, and it has tremendous stress tolerance."

It's high in provitamin A and protein, too, much higher than the traditional white potato. There's just one small problem: Hardly anyone in the world prefers the flavor of a sweet potato enough to plant and eat it in large quantities.

Tasting The 'Veggies' of Their Labor

So Kays and McLaurin set out to breed a non-sweet version of the crop. They began crossing sweet potato varieties in 1990 in an attempt to waylay the enzyme that creates such a sweet taste. Eventually they hit on a promising version that also appeared to be quite resistant to disease. Along the way, the two researchers did the bulk of the dirty work in their study: the tasting.

"Most of the lines were just dreadful," Kays said.

But the eventual winner was virtually indistinguishable -- in flavor, texture and even appearance -- from a plain white potato. Kays said they were lucky to hit a winner relatively early in the experiments.

"We picked the right parents," he said. "There's always an element of luck in any breeding program. You want to pick parents who possess those critical genes you need."

During the years since, Kays has been testing and talking up the potato among foreign governments and aid officials, including one recent high-profile UGA visit to North Korea. Kays soon will be sending propagation material for the North Koreans to try out -- good news for a nation in the throes of devastating famine, one where the white potato crop has failed as often as it has succeeded in recent years.

It Grows Just About Everywhere

"The sweet potato is really durable," Kays said. "It can go through three or four weeks of bad environmental situations -- heavy rain, little rain -- and still make a crop. This has real food security potential."

Thanks to McDonalds, the Chinese people have discovered they like french fries. While sweet potatoes can be produced in China for 40 percent less than white potatoes, only a small percentage is being used for human consumption because of its flavor. Kays' new sweet potato will change this.

It also could mean good news for Georgia farmers, who already grow a limited amount of the crop, but are set to expand production if markets swell.

Kays and McLaurin now plan to create sweet potatoes with other flavors and traits -- based upon consumer preferences or need. They are interested in creating an exceptionally high provitamin A sweet potato that could be used to combat vitamin A deficiency, which results in blindness for up to 500,000 children around the world each year. Another possibility is a blander sweet potato that can be added easily to processed foods to increase their nutritional content and bulk.

"The white potato is used in approximately 10,000 kinds of processed foods right now," Kays said. "I could see some of these products incorporating a blend of a new kind of sweet potato instead."

Paul Karr is an award-winning science journalist and writing coach who contributes regularly to the University of Georgia's Research Reporter magazine. This article is reprinted with permission from the University of Georgia's Research Reporter magazine.