Food & Nutrition Research Briefs, April 2007
Grilled
catfish with strawberry salsa. Image courtesy of The Catfish
Institute. |
America loves catfish!
In fact, it's the fourth most frequently
eaten fish in the United States. And, it's the star of ongoing studies by ARS
scientists with the Catfish Genetics Research Unit, Stoneville, Miss., and
their university colleagues.
These investigators are intent on
unlocking the secrets of the genetic makeup of catfishthe catfish genome.
Its about one-third the size of the human genome.
The findings can lead to superior,
farm-raised catfish for tomorrow.
The scientists have already identified
thousands of stretches of catfish genetic material, called DNA markers. The
markers can be used in the hunt for genes that control valuable traits like
larger fillets or improved resistance to common diseases.
For details, contact:
Geoffrey
C. Waldbieser, (662) 686-3593; USDA-ARS
Catfish Genetics Research Unit, Stoneville, Miss.
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Blueberries helped lower LDL
cholesterol in lab animals. |
Blueberries may help control cholesterol
and battle colon cancer, preliminary studies with laboratory animals suggest.
Hamsters that ate high-cholesterol chow, to which freeze-dried blueberry skins
had been added, had nearly 20 percent less LDL cholesterolthe "bad"
kindin their blood (plasma) than did hamsters not fed the
blueberry-spiked rations, an ARS-led study has shown.
Blueberry compounds such as resveratrol
and pterostilbene may be key to the cholesterol-lowering effect, according to
ARS scientists in the Natural Products Utilization Research Unit, Oxford,
Miss.
Another collaborative study, this one
directed by Rutgers University scientists, showed that nine laboratory rats fed
rations to which a small amount of pterostilbene40 parts per
millionhad been added developed 57 percent fewer induced colon lesions
than nine other rats not given the compound (Clinical Cancer Research,
volume 13, pages 350 to 355).
For details, contact:
Agnes
M. Rimando, (662) 915-1037; USDA-ARS
Natural
Products Utilization Research Laboratory, Oxford, Miss.
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Rich sources of
copper include nuts, sunflower seeds, lobster and more. |
Copper helped reverse unhealthy
enlargement of the heart, called cardiac hypertrophy, in laboratory
micean effect that scientists hope could also occur in humans afflicted
with the condition. The work, reported recently in the Journal of
Experimental Medicine (volume 204, pages 657 to 666), represents the first
time this copper-related benefit has been shown.
An enlarged heart can be associated with
shortness of breath, pain resulting from a decrease in blood supplied to the
heart, and abnormal heart rhythms.
All mice in the study had enlarged
hearts, but the condition reversed itself in the mice that were fed the
equivalent of three times the amount of copper recommended for human health.
Though high, the dose was nevertheless well below today's safe upper limit for
copper, a nutrient essential for good health.
ARS scientists with the Grand Forks
(N.D.) Human Nutrition Research Center collaborated in the study, which was led
by colleagues at the University of Louisville Medical Center in
Kentucky.
A handy list of foods that are good
sources of copper is posted at:
www.nal.usda.gov/fnic/foodcomp/Data/SR17/wtrank/wt_rank.html
Scroll down to the line that reads
"copper," then click on the "W" in the columnto the rightheaded
"sorted by nutrient content."
For details, contact:
Gerald
F. Combs, Jr., (701) 795-8456; USDA-ARS
Grand Forks Human Nutrition Research Center, Grand Forks, N.D.
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Early
Augustprince peaches. |
Two new kinds of firm and luscious
freestone peaches for southeastern U.S. orchards can help meet peach lovers'
demand for the delectable fruit.
Early Augustprince ripens in mid- to late
July. Augustprince follows, ripening in late July to early August.
Both new varieties yield large, round
fruit that's nearly three inches in diameter. When ripe, the skin is 70 to 80
percent bright-redwith an attractive yellow background. The yellow flesh
has some red if allowed to mature on the tree, and has a pleasing texture and
flavor.
A decade of tests by ARS scientists with
the Southeastern Fruit and Tree Nut Research Laboratory and by Clemson
University researchers in South Carolina showed that Early Augustprince and
Augustprince can outperform other currently planted commercial peach varieties
that ripen at about the same time of year in the Southeast. Several fruit tree
nurseries in Tennessee sell these new varieties.
For details, contact:
William
R. Okie, (478) 956-6405; USDA-ARS
Southeastern Fruit and Tree Nut Research Laboratory, Byron, Ga.
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Helpful bacteria may protect
fresh-cut fruit from foodborne pathogens. |
Good-guy bacteria quelled Listeria
monocytogenes, a food-poisoning microbe, in laboratory tests with freshly
cut honeydew melon pieces artificially infected with the pathogen. Scientists
found that a bacterium known as Gluconobacter asaiwhich occurs on
apples and some other fruitcan work in tandem with what are known as
bacteriophages to kill nearly all L. monocytogenes on the fruit.
Bacteriophages are harmless to humans.
The work may lead to new options that
enable food processors to meet the zero-tolerance standard for L.
monocytogenes in processed, fresh-cut fruits and vegetables.
Researchers at the ARS Henry A. Wallace
Beltsville (Md.) Agricultural Research Center and the ARS Appalachian Fruit
Research Station, Kearneysville, W.Va., collaborated in the work with
Intralytix, Inc., Baltimore, Md.
For details, contact:
William
S. Conway, (301) 504-6128; USDA-ARS
Beltsville Agricultural Research Center, Beltsville, Md.; or
Wojciech
J. Janisiewicz, (304) 725-3451, ext. 358; USDA-ARS
Appalachian Fruit Research Station, Kearneysville, W.Va.
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Tea, red wine and apples contain flavonoids known
as catechins. |
Health-imparting plant compounds called
flavonoidslike the cyanidin in cherries or catechins in teamay
reduce risk of certain diseases, studies have suggested. A newly updated,
easy-to-use database from ARS nutrition researchers documents levels of 26 key
flavonoids in about 400 fruits, vegetables and other foods.
Details on how to access the USDA
Database for the Flavonoid Content of Selected Foods, Release 2.1 (2007),
are posted on the World Wide Web at:
www.ars.usda.gov/nutrientdata/flav
Scientists with the ARS Beltsville (Md.)
Human Nutrition Research Center used their own analyses of selected foods and
beverages, along with data from nearly 100 new scientific papers on foods
flavonoid content, to compile the update.
Key users of the database include
researchers worldwide who are investigating the relation between flavonoids and
reduced risk for cancer and other chronic diseases.
The database is a special supplement to
the National Nutrient Database for Standard Reference, SR19, regarded as
the nation's most authoritative source of food composition information.
For details, contact:
David
B. Haytowitz, (301) 504-0714; USDA-ARS
Beltsville Human Nutrition Research Center, Beltsville, Md.
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High beta-carotene
cauliflower. |
Unique cauliflower, equipped naturally
with a special gene that causes it to become orange instead of the familiar
white, or even green, may hold the key to boosting the nutrients in other
foods.
Scientists already know that a gene
called Or, short for orange, cues the veggie to form
beta-carotenea compound that causes it to turn orange. Our bodies can use
beta-carotene to form vitamin A, an essential nutrient. Most Americans don't
get enough vitamin A from food, leading to researchers' interest in the
Or gene as a key to creating beta-carotene-enriched plants for
tomorrow.
Though investigators have known of the
existence and role of the Or gene for many years, it wasn't until
recently that ARS scientists and their Cornell University colleagues pinpointed
and copied it. They're taking a detailed look at the gene's activity to learn
exactly how it cues the plant to produce and store the color-imparting
compound. They describe some of their newest discoveries in The Plant
Cell (volume 18, pages 3594 to 3605).
For details, contact:
Li
Li, (607) 255-5708; USDA-ARS U.S.
Plant, Soil and Nutrition Laboratory, Ithaca, N.Y.
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Richard Novy (left) and Dennis Corsini (now
retired) examine Alturas potato plants and tubers. |
Versatile and tasty, Alturas potato is a
top-quality spud from ARS researchers in Aberdeen, Idaho, and their
co-investigators. First made available to growers about five years ago, Alturas
today rates as the fifth most commonly planted potato in Idahothe state
that produces more potatoes than any other.
America's favorite veggie, potatoes
provide fiber, vitamin C, potassium and other essential nutrients.
Alturas is suitable not only for
processing into frozen potato productsor dehydrated foods such as instant
potato flakesbut also for fresh-pack sale at your local supermarket
(American Journal of Potato Research, volume 80, pages 295 to 301).
Researchers had put Alturas though about
a decade of evaluationsincluding taste tests, trials in research fields
and experiments at potato-processing plantsbefore determining it was
ready for western U.S. farms.
For details, contact:
Richard
G. Novy, (208) 397-4181, ext. 111; USDA-ARS
Small Grains and Potato Germplasm Research Unit, Aberdeen, Idaho
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Assorted quince from ARS in Corvallis, Oregon. |
Quince trees from around the planet are
safeguarded in America's official quince collection, located at the ARS
National Clonal Germplasm Repository in Corvallis, Ore. A bright-yellow, fuzzy
cousin of pears and apples, quince is worth conserving not only for its own
sake, but also for that of pears. That's because quince provides a "dwarfing"
rootstock to which pears can be grafted, forming easy-to-manage, early-fruiting
pear trees.
Trees from Armenia and the Republic of
Georgia have recently been added to the collection, the largest publicly owned
assortment of quinces in the United States. What's more, studies of the
characteristics and genetic makeup of these trees may reveal prized traits such
as cold-hardiness, or resistance to the microbe that causes fire blight
disease. Those traits could be bred into other quinces to create superb new
trees for tomorrow.
For details, contact:
Joseph
D. Postman, (541) 738-4220; USDA-ARS
National Clonal Germplasm Repository, Corvallis, Ore.
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Soybean saponins showed cancer-fighting effects in
lab animals. |
Cancer-preventing properties of
saponinsnatural compounds found in soybeans and a variety of other
plantsare now easier to study. That's thanks to a new technique to more
readily extract and purify them.
ARS scientists at the agency's National
Center for Agricultural Utilization Research, Peoria, Ill., and colleagues at
the University of the Incarnate Word, San Antonio, Texas, did the work
(Journal of Agricultural and Food Chemistry, volume 54, pages 2035 to
2044).
Saponins' cancer-fighting effects have
been shown in studies such as a 2005 investigation in which ARS and University
of Illinois scientists found that exposing cancerous human colon cells to
saponins reduced the cells' growth by 27 to 68 percent (Carcinogenesis,
volume 26, pages 159 to 167).
For details, contact:
Mark
A. Berhow, (309) 681-6347; USDA-ARS
National Center for Agricultural Utilization Research, Peoria,
Ill.
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Onions are chock full of
heart-healthy nutrients. |
Sweet-yet-sharp onions are definitely
palate pleasers, but their stronger flavored cousins pack more of a nutritional
punch. ARS plant geneticists are learning more about onions' nutrient-imparting
genes so that tomorrow's most popular types might provide more
nutrientsalong with the familiar flavors and textures.
The research focuses on genes responsible
for three different groups of health-enhancing compounds: blood-thinning
thiosulfinates, fiber-rich fructans and flavonoids such as quercetin that help
protect the body against oxidative damage.
Working in cooperation with scientists in
New Zealand and Japan, ARS scientists based at the Vegetable Crops Research
Unit, Madison, Wis., already have found several genes of interest, including
one that helps onions accumulate fructans (Theoretical and Applied
Genetics, volume 112, pages 958 to 967). The more fructans there are, the
more heart-healthy thiosulfinates there'll be, too.
For details, contact:
Michael
J. Havey, (608) 262-1830; USDA-ARS
Vegetable Crops Research Unit, Madison, Wis.
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Peanut flour studies may open
the door to increased use of this protein-rich ingredient. |
Nutrition bars, salad dressings,
saucesand moreall benefit from the flavors, textures and proteins
provided by peanut flour. Now, tests by ARS scientists have shown that
lower-fat peanut flours can thicken more effectively than higher-fat
ones.
The researchers, who work at the Market
Quality and Handling Research Unit, Raleigh, N.C., report this and other new
findings about the versatile flour in the Journal of Texture Studies
(volume 38, pages 253 to 272).
For details, contact:
Jack
P. Davis, (919) 515-6312; USDA-ARS
Market Quality and Handling Research Unit, Raleigh, N.C.
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