Food & Nutrition Research Briefs, April 2005
Cheese: a source of vitamin B12.
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A newly reported study links vitamin B12
deficiency with low bone-mineral density in men, and it confirms similar,
previously reported findings in women.
ARS-funded researchers at the Jean Mayer USDA
Human Nutrition Research Center on Aging, Boston, Mass., based these findings
on their investigation of vitamin B12 blood levels and bone health indicators
of 2,576 men and women, age 30 to 87 (Journal of Bone and Mineral
Research, volume 20, pages 152-158). Animal-protein foods such as fish,
beef, pork, milk and cheese are good sources of vitamin B12.
Contact:
Katherine L. Tucker, (617)
556-3351;
ARS
Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts
University, Boston, MA.
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Soybeans.
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Meals with protein from meat or soy didn't
harm the bone health of 13 postmenopausal volunteers in an ARS study.
Scientists at ARS' Grand Forks (N.D.) Human Nutrition Research Center and
colleagues at the ARS Arkansas Children's Nutrition Center also determined that
the volunteers, age 52 to 69, absorbed and retained calcium equally well from
regimens containing meat or meat plus soy protein. Their findings appeared in
the January 2005 issue of the Journal of Clinical Endocrinology &
Metabolism (volume 90, pages 181-189).
By the study's end, volunteers had completed
each of two different seven-week stints. The regimens featured well-balanced
meals that provided, among other nutrients, average amounts of protein
primarily from animal sources, or--on the other regimen--from soy and
meat.
Researchers found no significant difference
in volunteers' bone health after either regimen. That's contrary to a popularly
held theory that high-meat regimens may leach calcium from bones. It also
suggests that soy's phytate doesn't interfere with the body's ability to absorb
minerals.
Contact:
Janet
R. Hunt, (701) 795-8328; USDA-ARS
Grand
Forks Human Nutrition Research Center, Grand Forks, N.D.
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Measuring bone density.
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Bone-health studies of preteens, young women
and postmenopausal volunteers are revealing more details about the roles of
nutrition and exercise in preventing osteoporosis.
Iowa State University researchers are
collaborating with scientists from the ARS Western Human Nutrition Research
Center, Davis, Calif., in a new study of soy supplements' effects on the bone
health of more than 200 healthy, postmenopausal volunteers. Preliminary results
are expected next year.
An earlier investigation, reported in 2003
and led by Stanford University scientists in collaboration with ARS and
University of California at Berkeley researchers, looked at the eating, health
and exercise histories of women volunteers in their preteens through early 20s.
The findings confirmed those of other
studies, done elsewhere, and underscored the importance of exercising and
eating calcium-rich foods. Volunteers who exercised more in their preteen years
and ate a daily average of more than 1,000 mg of calcium had better bone health
when they reached their 20s than did volunteers who exercised less and consumed
less calcium (American Journal of Clinical Nutrition, volume 77, pages
495-503).
Contact:
Marta
D. Van Loan, (530) 752-4160; USDA-ARS
Western
Human Nutrition Research Center, Davis, CA.
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Citrus: rich in limonoids.
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ARS studies give us even more to like about
oranges, already America's favorite fruit. Oranges and some other kinds of
citrus are rich in limonoids, which have been shown in lab tests with animals
or human cells to help fight certain cancers.
Scientists based at the ARS Western Regional
Research Center, Albany, Calif., demonstrated--several years ago--that each
time we eat citrus fruit or drink citrus juices, our bodies readily access a
limonoid called limonin (Journal of Agricultural and Food Chemistry,
volume 51, pages 4156-4161). New ARS study will look at limonin's
cholesterol-lowering effects in healthy volunteers, a first-of-its-kind
investigation.
Contact:
Gary D.
Manners, (510) 559-5813; USDA-ARS
Western
Regional Research Center, Albany, CA.
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Gulfking peaches.
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Gulfking and Gulfcrest, two delicious new
peaches from ARS plant breeders in Byron, Ga., and their University of Florida
and University of Georgia colleagues, may begin showing up in the produce
section of some supermarkets this year.
Intended for growing in the southeastern
states, both of these peaches have sweet, firm flesh that does not brown easily
when bumped or cut.
Gulfking typically ripens in early May;
Gulfcrest is ready to pick from early- to mid-May.
Contact:
Thomas
G. Beckman, (478) 956-6436; USDA-ARS
Southeastern
Fruit and Tree Nut Research Laboratory, Byron, GA.
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Hardy kiwifruits, in front of their larger
commercial cousins.
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Kiwifruit that's sold in supermarkets coast
to coast has a lesser-known, grape-sized cousin called hardy kiwifruit. The
mini-kiwi is fuzzless, but inside it has the same sweet-tart, green flesh and
tiny, black seeds as its egg-sized relative.
The leading kind of small kiwifruit that's
grown in the United States ripens in mid-September and can be stored for only a
few weeks. That's why scientists working at the ARS National Clonal Germplasm
Repository and at the ARS Horticultural Crops Research Laboratory, both in
Corvallis, Ore., are developing a slightly larger, earlier-ripening version of
the junior-sized kiwifruit.
Contact:
Kim E.
Hummer, (541) 738 4201; USDA-ARS
National
Clonal Germplasm Repository, Corvallis, OR.
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Vigna unguiculata L. (Image courtesy
USDA-NRCS PLANTS Database).
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Southernpeas, rich in protein, are primarily
sold canned or frozen for serving with spicy rice, adding to soups or enjoying
in other entrees or side dishes. Two outstanding new southernpeas from ARS
scientists at the U.S. Vegetable Laboratory, Charleston, S.C., are
drought-resistant, will thrive on poor soils and are well-suited to growing in
southeastern states.
Charleston Blackeye resists attack by
root-knot nematodes and is intended for fresh-market growers or home gardeners
who like the taste of traditional, fresh-shell blackeye peas. Baby Cream yields
small, delicate, succulent peas with a milder, less starchy flavor.
Contact:
Richard
L. Fery, (843) 402-5300, ext. 5301, or
Judy A.
Thies, (843) 402-5300, ext. 5317; USDA-ARS
U.S.
Vegetable Laboratory, Charleston, S.C.
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Researchers examine freshly harvested
oysters.
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A novel protein with the tongue-twisting name
of phosphoglucose isomerase may raise the likelihood of getting sick after
eating contaminated shellfish.
Scientists at the ARS Microbial Safety of
Aquaculture Products Center of Excellence, Dover, Del., and their colleagues
discovered that this protein occurs in Vibrio vulnificus. Then they
provided many new details about the protein's activity, and showed that it
occurs in virtually all of the Vibrio species they tested.
The scientists note that the research has led
to new methods for rapidly detecting the infectious bacteria. New methods to
kill the microbes may follow.
Contact:
Gary P.
Richards, (302) 857-6419; USDA-ARS
Microbial Safety
of Aquaculture Products Center of Excellence, Dover, DE.
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Surface plasmon resonance analysis of eggs.
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A new approach to detecting food contaminants
should help industry and government food-safety inspectors keep foods safe for
us to enjoy. ARS scientists at the Eastern Regional Research Center, Wyndmoor,
Pa., have partially automated an optical method called surface plasmon
resonance, or SPR, for inspecting foods such as ham, whole liquid eggs and
milk.
They've shown that the technology, already
used at some food processing plants to monitor other contaminants, can detect
and measure the quantity of gastroenteritis-causing toxins A and B of
Staphylococcus.
Conventional heating and other
food-processing procedures can kill certain pathogens but not necessarily zap
their heat-resistant toxins, the scientists note. Their findings appear in the
Journal of Rapid Methods and Automation in Microbiology, volume 2, pages
38-54.
Contact:
Marjorie
B. Medina, (215) 233-6436; USDA-ARS
Eastern
Regional Research Center, Wyndmoor, PA.
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Escherichia coli.
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Foodborne pathogens like Campylobacter
can develop resistance to antibiotic drugs used in raising livestock. So ARS
scientists in Athens, Ga., are determining and documenting the microbes'
characteristics in healthy or sick farm animals.
The resulting database--the nations
largest about antibiotic resistance of Campylobacter,
Enterococcus, Escherichia coli and Salmonella--may help
researchers detect resistance patterns, a formidable challenge. For instance,
each of the more than 2,400 Salmonella types appears to develop
resistance at a different rate.
Contact:
Paula
Fedorka-Cray, (706) 546 3305;
USDA-ARS
Richard B. Russell Research Center, Athens, GA.
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Examining wheat plants.
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Your favorite breads may owe much to the
baker's skill and the top-quality wheat flour used in making the delectable
loaves. In turn, the excellence of wheat flours is due, in large part, to the
work of hundreds of different proteins in the wheat kernels from which flour is
milled.
By taking a closer look at these proteins,
ARS scientists at the Western Regional Research Center hope to create even
better wheat flours for tomorrow. Some of these proteins' jobs range from
storing carbohydrates to protecting kernels against insects.
Though similar research has been done at
other labs to identify proteins and their functions in wheat, barley and
alfalfa, the California investigators are probably the first to delve this
deeply into the roles and changing ratios of wheat's lesser-known wheat-kernel
proteins. A recent article in Proteomics (volume 5, pages 1594-1611) has
details.
Contact:
William
J. Hurkman, (510) 559-5720; USDA-ARS
Western
Regional Research Center, Albany, CA.
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Walnut with pellicle partially removed (top
right).
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Walnuts--like several other foods--are
vulnerable to Aspergillus flavus and A. parasiticus fungi that
produce aflatoxin. Inspections ensure that walnuts are free of harmful levels
of aflatoxin, which is thought to be a carcinogen.
Earlier investigations by ARS Western
Regional Research Center scientists and university co-researchers determined
that high levels of a natural compound, gallic acid, prevent Aspergillus
from making aflatoxin in Tulare, one of the many kinds of English-type walnuts
grown in the United States today (Journal of Food Science, volume 68,
pages 619-622).
Gallic acid is a component of the tannins in
the pellicle, the thin skin that surrounds the nutmeat. Now the scientists
intend to solve the mystery of exactly how gallic acid thwarts
Aspergillus aflatoxin production.
Contact:
Russell
J. Molyneux, (510) 559-5812; USDA-ARS
Western
Regional Research Center, Albany, CA.
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The United States Department of
Agriculture (USDA) prohibits discrimination in all its programs and activities
on the basis of race, color, national origin, gender, religion, age,
disability, political beliefs, sexual orientation, and marital or family
status. (Not all prohibited bases apply to all programs.) Persons with
disabilities who require alternative means for communication of program
information (Braille, large print, audiotape, etc.) should contact USDA's
TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of
discrimination, write USDA, Director, Office of Civil Rights, Room 326-W,
Whitten Building, 14th and Independence Ave., SW, Washington, DC 20250-9410 or
call (202) 720-5964 (voice or TDD). USDA is an equal opportunity provider and
employer.
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