New corn varieties offer high levels of oleic acid.

New corn varieties bred by scientists at the Agricultural Research Service and Iowa State University may just do one's heart some good. In fact, the 14 new lines may lead to a variety of desirable corn-based products, like cooking oils and margarine, that keep blood cholesterol levels down or make salad dressings last longer.

Scientists have crossed traditional Corn Belt inbred lines with varieties cultivated during past independent studies that contain genes from eastern gamagrass, Tripsacum dactyloides. These lines were developed using traditional plant-breeding techniques. As a result, they can find use in applications that are resistant to biotechnology. The most promising of these Tripsacum-introgressed lines are ones with high percentages of oleic acid. This monounsaturated fatty acid may be the key to healthier corn products.

High percentages of oleic acid give corn oil stability with regard to flavor and deterioration. They've also been linked to lower blood cholesterol levels in humans. High-oleic corn oil also provides good starting material for making margarine. That's because replacing polyunsaturated fatty acids with oleic acid could means that less processing is needed to create the hardened spreadable product.

A high-oleic oil contains a lower percentage of the other types of fatty acids. You get fewer negative effects from either polyunsaturated or saturated fatty acids while maintaining their many good properties. These features may be a boon to producers of corn-based cooking oils, who have lost customers to high-oleic alternatives such as olive oil and canola oil.

Oleic acid's stability, which makes for longer storage and refrigerator shelf life, may also prove attractive to makers of salad dressing. Many salad dressings use very polyunsaturated soybean or canola oils, which don't have high stability and thus can become rancid relatively quickly.

Some of the new Tripsacum-introgressed corn lines lines yield oils containing 60% to 70% oleic acid, compared to the 20% to 30% levels found in commercially available corn oils. Varieties have been developed that have oils with total saturated fatty acid composition as low as 6.5%, compared to the 13% found in corn oils currently available.

Researchers have submitted a patent application (No. 09/285,368) for the Tripsacum-introgressed corn lines, and they are seeking commercial partners. The corn lines are ready to be used in a commercial breeding program. Future research on the subject will focus on two areas: examining the types of products that can use the high-oleic lines and crossing the new lines with existing corn varieties.

Further information. Susan Duvick, USDA-ARS North Central Regional Plant Introduction Station, 3503 Agronomy Building, Iowa State University, Ames, IA 50011; phone: [phone]; fax: [phone]; email: [e-mail].