To Cut Trans Fats, You Need a Better Soybean Across the country, restaurants are under pressure to get rid of trans fats. But finding a healthier cooking oil that also holds up to extended use won't be easy. The search begins in the soybean fields of the Midwest.

To Cut Trans Fats, You Need a Better Soybean

To Cut Trans Fats, You Need a Better Soybean

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French fries close up

Why Do Fries Taste So Good? A Brief History

Finding a healthier cooking oil that still preserves that crispy, salty French fry goodness fast-food lovers crave won't be easy. But McDonald's — and the rest of the industry — has been through this before.

In fact, the signature taste of McDonald's fries came about as something of an accident. Read more.

For the last two years, "low-lin" soybean oil has been used in the deep fryers of the dining halls at Iowa State University. The school has found that trans-fat-free oil lasts twice as long as old-fashioned hydrogenated oil. Scott Horsley, NPR hide caption

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Scott Horsley, NPR

Iowa State University plant breeder Walter Fehr keeps specialty soybean oils in his office for "encouragement." Soybeans supply nearly 80 percent of all the oil used for cooking and baking in the United States. Scott Horsley, NPR hide caption

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Scott Horsley, NPR

Across the country, restaurants are under pressure to get rid of trans fats, which are made when hydrogen is added to vegetable oil; a July deadline looming in New York City. But it won't be easy to find a healthier cooking oil that can be produced at the scale needed to supply national chains and also hold up to extended use. The search begins in the soybean fields of the Midwest.

Nearly 80 percent of all the oil used for cooking and baking in this country comes from soybeans. But in their natural state, soybeans have a problem: a high concentration of linolenic acid, which makes their oil spoil quickly.

"It just doesn't have the shelf life that you would like to have in products," says Walter Fehr, a professor of agriculture at Iowa State University who has devoted most of his career to breeding soybeans for tofu, soy milk and especially oil. "And that's the reason that they switched many years ago to hydrogenation."

Stays Good Longer... But Not So Good for You

Hydrogenation extends shelf life. In the last century, the original Crisco and other partially hydrogenated oils became popular because they offered a lot of advantages. They make fried food crispy. They can be used over and over again. And they're inexpensive. But partial hydrogenation also creates trans fats, which are now known to increase levels of bad cholesterol. That's why Fehr has been busy breeding a soybean that doesn't need hydrogenation to stay fresh.

After decades of conventional breeding, Fehr developed a line of soybeans that have just 1 percent linolenic acid. But breeding these "low-lin" soybeans was only half the battle. Fehr also had to find farmers willing to grow the soybeans and processors willing to squeeze the oil out of them. Finally, he had to prove to restaurants that low-lin soybean oil would work in a large-scale, commercial environment.

Iowa State's residential dining halls have been cooking their French fries in Fehr's low-lin oil for the last several years, using fryers just like the ones in fast-food restaurants. Dining hall manager Erica Bierman says in head-to-head performance tests, the trans-fat-free oil actually lasted twice as long as old-fashioned hydrogenated oil.

"We noticed that we didn't have to change the oil every week," Bierman says. "We started to test how far we could hold the oil, and it ended up being about two weeks."

It's Healthier... But Does It Pass the Taste Test?

Another key consideration for restaurants is the texture and taste of food once it has been fried in oil. KFC rejected a trans-fat-free canola oil because it hid the flavor of the chicken's 11 herbs and spices. McDonald's says it backed away from a trans-fat-free oil in 2002 because the French fries didn't taste quite right.

That's why food-processing giant Archer Daniels Midland employs a full-time "sensory panel" to test ingredients such as cooking oil before they go to market.

"Our research chefs work with our ingredients to develop recipes around them, to see how those ingredients will work," says Research Vice President Mark Matlock. "One of the really important things with food is it has to taste good. [For] consumers, it's better if it's more nutritious, but it has to taste good."

Matlock says ADM has been working on its own line of trans-fat-free oils for both restaurants and packaged-food companies. A test tube bubbling away in the company's laboratory bears the name of the doughnut chain Krispy Kreme. Matlock says it's just as well that food makers have not switched away from trans-fat-filled oils in one fell swoop. Given the amount of oil used throughout the country, he says, the industry needs time to adjust.

"If everybody banned trans all at once, it would create some shortages, potentially, of the naturally stable oils," he says.

Finding a Steady Supply of Tasty Oil

One of the biggest challenges for a company of McDonald's size is ensuring an adequate supply of oil. At the moment, there aren't enough low-lin soybeans to go around. If all the restaurants in the country were to make the switch, they would need about 12.5 million acres of soybeans — an area the size of Massachusetts and New Jersey combined. Last year, less than a million acres of the special soybeans were planted. The acreage is expanding, but raising the soybeans — and keeping them separate from ordinary beans — takes extra effort. And professor Fehr says that not every farmer is willing to do that.

"The farmer is going to be the one who decides whether or not this is going to work in soybeans, pure and simple," Fehr says. "And the challenge right now for the 2007 crop is whether enough farmers are going to be willing to grow these beans."

Farmers do receive a premium for growing low-lin soybeans. But this year, they might make even more money growing plain old corn, thanks to the growing demand for the gasoline additive ethanol. That presents a dilemma for growers like Dan Allen, who farms a few thousand acres in Iowa's Madison County.

"I don't think we've figured out what we're going to grow," Allen says. "With the profitability of corn increasing, they're going to have to pay some real dollars in order to buy the beans to fill their contracts."

The young low-lin soybean industry will only succeed if the price is low enough for restaurants — and high enough for farmers. Allen says when planting time comes in April, he'll grow whichever crop makes the most money. But he's crossing his fingers that the low-lin soybeans catch on.

After all, he says, "I eat French fries, too."