In the future, a food oil pressed from a new line of
soybeans could become a close runner up to olive oil in terms of its
heart healthy levels of monounsaturated fat. Olive oil enjoys a fine
reputation among nutritionists because of its relatively high levels
of monounsaturated fat (nearly 75 percent of total fat).
The USDA-ARS National
Soybean Germplasm Collection in Urbana, Illinois, recently received
soybean genetic material, or germplasm, with higher monounsaturated
fat concentrations than any other previously included in the collection.
The NSGC preserves such plant material for use in developing improved
The new germplasm, called N98-4445A, was developed through
traditional breeding methods by scientists led by agronomist Joseph
W. Burton, with the ARS Soybean and Nitrogen Fixation Research Laboratory
in Raleigh, North Carolina. "The germplasm will be a useful genetic
resource for breeding mid-oleic soybean varieties suitable for different
growing regions," he says.
Oil from N98-4445A contains increased levels of oleic
acida monounsaturated fat stable enough for use in salad dressings
or frying oils without treatment by the hardening process called hydrogenation.
Hardening is achieved by chemically adding hydrogen to a chain of oil
molecules. While hydrogenation serves as a stabilizer to make oils suitable
in solid products such as margarines, breakfast bars, and baked goods,
it also creates trans isomers, which are known as less healthy trans
fats. "The new oil would likely be as stable as hydrogenated oils,
but without the trans isomers," says Richard F. Wilson, ARS's national
program leader for Oilseeds and Bioscience. "Oils based on this
new line would likely not oxidize as quickly as other soybean oils."
The germplasm line's increased oleic acid level also correlates
to a decrease in polyunsaturated fatty acids (PUFAs). PUFAs are liquid
fats (such as linoleic and linolenic acids) that are known to cause
off-odors and break down when oxidized during aging or frying. While
commercial soy oils are 7 percent linolenic acid, the new line has only
3 percent of that highly unstable PUFA. In comparison, even a 4-percent
content might require some hydrogenation. Oils based on the new generation
would fall below a critical cut-off point under which no hydrogenation
By 2006, U.S. Food and Drug Administration plans would
require food manufacturers to state the amount of trans fatty acids
in processed foods. The processed-food industry uses tons of vegetable
oils in myriad products annually. About half of all vegetable oil produced
is from soybeansthe most used vegetable oil in the world.By
Rosalie Marion Bliss,
Agricultural Research Service Information Staff.
Joseph W. Burton
is with the USDA-ARS Soybean
and Nitrogen Fixation Research Laboratory, 3127 Ligon St., Raleigh,
NC 27695; phone (919) 515-2734, fax (919) 856-4598.
"Pedigreed Soybean Promises Healthier Soy Oil" was
published in the February
2004 issue of Agricultural Research magazine.