Soybeans are a
chief source of edible oil in the U.S. New research could improve the oil's
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Genetic Markers Point Toward Low-Linolenic-Acid
Soybeans By Laura
McGinnis March 31, 2006
Agricultural Research Service (ARS) scientists in the
Genetics Research Unit at Columbia, Mo., are improving soybean oils
longevityand marketabilityby lowering its linolenic acid
Most soybeans contain high levels of linolenic acid, which has double
chemical bonds that break down in the presence of air, heat and light,
according to molecular biologist
Bilyeu at Columbia. This is a troublesome trait for producers and consumers
who want durable, shelf- stable food.
Soy oil is often partially hydrogenated to reduce linolenic acid.
Hydrogenation increases products shelf life and stability, but produces
trans fats (also called trans fatty acids), which several studies have linked
to high cholesterol and heart disease.
With growing public awareness and new laws requiring food labels to
list trans fats, the food oil industry would welcome an alternative to
hydrogenated oils. Could low-linolenic soybeans provide the solution?
With colleagues from ARS and Iowa
State University (ISU), Bilyeu has developed molecular markers that
identify specific mutations in three genes which can be used in plant breeding
programs to lower soy oils linolenic acid content. Oil from the
low-linolenic soybeans does not require hydrogenation.
Walter Fehr of ISU and James Wilcox, formerly with ARS, identified the
low-linolenic soybean lines in mutant plants that Bilyeu used to identify the
mutant genes and develop the molecular markers.
Usually, soybean breeders depend on random segregation of the three
genes for low-linolenic acid. Using these new markers will improve the
identification of soybean genotypes for low linolenic acid content. Eventually,
Bilyeu hopes the breeding process will result in stable, nutritious beans for
the food oil industry.
Initiative, under the auspices of the
United Soybean Board, is helping to
bring seed companies, processors, and food manufacturers together to expand the
market for low- linolenic soybean oil. This oil would create a competitive
advantage for growers and allow food manufacturers and vendors to market
long-lasting products without compromising their nutritional value.
ARS is the U.S. Department of
Agricultures chief scientific research agency.