Corn Fiber Yields Oil and Gum
Chemist Kevin Hicks checks the color and quality of a corn fiber oil sample.
From the hull of a kernel of corn, Agricultural Research Service scientists,
with help from the University of Massachusetts, have discovered and patented a
new corn fiber oil that may lower serum cholesterol levels. A second new
product a valuable white corn fiber gum was also discovered in the fibrous hull
and is being patented by ARS.
This research has captured the interest and backing of two major companies,
Monsanto and the National Starch and Chemical Company. It could also lower the
cost of producing other corn-derived products, like fuel ethanol.
"These companies have signed agreements to further develop the
technology," reports Kevin B. Hicks. "Eventually, this should create
jobs, provide new uses for agricultural byproducts, increase income for
processors and growers, and develop healthy new food products for consumers.
Hicks, along with fellow chemists Robert A. Moreau and Robert A. Norton,
discovered the new corn oil. He heads the Plant Science and Technology
Research Unit of ARS' Eastern Regional Research Center (ERRC) in Wyndmoor,
Pennsylvania, where Moreau leads the corn fiber research project. Norton is
based at ARS' National Center for Agricultural Utilization Research in Peoria,
Preliminary studies with hamsters by collaborator Robert Nicolosi, a
nutritional biochemist who directs the University of Massachusetts Center for
Cardiovascular Disease Research, indicate that the new corn fiber oil
significantly lowers total serum cholesterol and LDL cholesterol, which is the
kind that clogs the arteries. The patent application for
"AmaizingOil," made jointly with the University of
Massachusetts, covers the process for extracting the oil from the fiber, use of
the oil to produce cholesterol-lowering products, and individual components of
To remove oil from corn hull fiber, chemist Robert Moreau pours a sample into a
supercritical fluid extractor.
"We knew that the corn milling industry produces huge amounts of corn
fiber residue that is made into livestock feed and sold for only about 5 cents
a pound," says Hicks. "We wanted to turn this potential waste
disposal problem into an opportunity, which we did by processing cheap fiber
into valuable new products for which there would be a strong market."
Corn fiber is a low-value byproduct of wet milling, the industrial process
that produces starch, sweeteners, fuel grade ethanol, and other products from
corn. The corn processing industry produces about 4 million tons of corn fiber
each year, which could yield about 80,000 tons of corn fiber oil. This fiber is
now sold as corn gluten feed, a low-cost ingredient in cattle rations.
Just how did Robert Moreau's team discover corn fiber oil?
"I knew that Bob Norton in the ARS Peoria lab had done some work with
the cholesterol-lowering potential of compounds in corn bran, which is similar
to corn fiber except that it's produced by dry milling, instead of wet,"
Moreau explains. "So I took a closer look at exactly what happens to a
kernel of corn during wet milling."
In wet milling, the first step is to steep, or soak, the kernels in water to
soften and swell them. After steeping with sulfites for 2 days at
140oF, the soft kernels break into four products the germ, starch, a
high-protein product, and the hull, or fiber.
"We extracted the new oil from the outer hull, or seed coat.
Conventional corn oil comes from the germ," Moreau says.
Moreau collaborated with Nicolosi on preliminary feeding studies. When
Nicolosi's results showed that the corn fiber oil significantly lowered total
serum cholesterol in hamsters, the team was off and running.
Under terms of the ARS agreement with the University of Massachusetts,
university cooperators have the right to grant licenses for the process. On
July 23, 1997, they issued an exclusive license to Monsanto of St. Louis,
Missouri, to further develop the corn fiber oil technology.
Chemist Landis Doner prepares a sample of corn fiber gum for analysis of color
Monsanto will provide several hundred thousand dollars in upfront payments,
royalties on future sales of corn fiber oil products, and potentially several
million dollars in payments as various milestones are reached. Monsanto will
also supply considerable funding for ARS corn fiber research.
"We plan to use this oil in a variety of food applications, hoping it
will lower cholesterol levels. We're excited about working with ARS and the
University of Massachusetts over the next couple of years," says Charles
Hough. He is director of business development for Monsanto. "ARS' idea of
taking a low-value product and turning it into a healthy food is consistent
with Monsanto's mission of helping people live longer, healthier lives,"
says Hough. "This is an area we'd like to focus on in the future."
After Moreau had extracted the corn fiber oil, he gave the defatted fiber to
colleague Landis W. Doner, also a chemist and member of the corn fiber team at
The defatted fiber is about 50 percent hemicellulose, a polysaccharide that
is a carbohydrate more complex than sugar. Doner hit pay dirt when he
discovered a way, using alkaline hydrogen peroxide, to separate and extract the
hemicellulose from the corn fiber.
"For about 50 years, researchers have been searching for ways to
produce a viable gum from byproducts of the corn processing industry. Several
processes have even been patented, but none have been commercialized because
all the materials were tan to brown in color," Doner explains. "Food
processors and industrial users want corn fiber gum with very little
Doner's corn fiber gum is extracted as a smooth, white powder, bland in
flavor and aroma. When mixed with water, it looks and acts like a gum. The gum
could be used in foods as an emulsifier, a soluble dietary fiber, or a
thickener. Industrial applications could include adhesives and water-based
While corn fiber yields 2 percent oil, Doner says it yields 40 percent gum.
Doner and Hicks have applied for a patent for "Zeagen" and
recently signed a cooperative research and development agreement with the
National Starch and Chemical Company (NSCC) of Bridgewater, New Jersey.
"We're anxious to get started on scaling up this process to find a wide
range of food and nonfood uses," says Roger Jeffcoat, NSCC's divisional
vice president for natural polymer research and biotechnology.
Believe it or not, there's still more to this research project.
"Currently, the United States has an enormous trade deficit, about 40
percent of which is due to our importing petroleum," says Hicks.
"Valuable coproducts from this corn fiber research will offset the cost of
making all corn-derived products, including fuel ethanol. If we can replace
imported petroleum with our homegrown fuel ethanol, we could have an impact on
the national economy.
[For more on ethanol production, see "Improving
Ethanol Yield From Corn," Agricultural Research, October 1996,
Currently, the cost of fuel ethanol makes it very difficult to compete with
gasoline. But valuable new products will hopefully lower net costs for ethanol
"Coproducts now decrease the cost of ethanol by about 60 cents a
gallon," says Hicks, and our new technologies should lower this even more.
Our goal, like that of our partners in these ventures, is to help growers,
industry, and consumers." By Doris Stanley
Moreau, is in the USDA-ARS Crop Conversion Science and Engineering Research
Unit, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA
19038-8551; phone (215) 233-6428
Center for Agricultural Utilization Research, 1815 N. University St.,
Peoria, IL 61604