Food & Nutrition Research Briefs, July 2007
Eating fruits like strawberries could boost levels
of antioxidants in our blood and lead to a lower risk of chronic degenerative
disease.
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New details about the antioxidant power of
more than a half-dozen fruits have emerged from studies led by an antioxidants
expert based at the ARS Arkansas Children's Nutrition Center, Little Rock, Ark.
(Journal of the American College of Nutrition, volume 26, pages 170 to
181).
Antioxidantscolor-imparting compounds
in fruits and veggiesare thought to stall aging, ward off disease and
reduce the harmful effects of molecules known as oxygen free radicals.
Researchers measured blood (plasma)
antioxidant capacity, or AOC, of volunteers shortly after these healthy women,
age 18 to 70, had eaten blueberries, cherries or dried plums, or had downed
10.6 ounces of dried-plum juice. Analysis of the samples confirmed that
antioxidants in some foods apparently are easier to absorb and use than others.
Dried plums, for instance, did not raise volunteers' plasma AOC levels, perhaps
because one of plums' most plentiful antioxidantschlorogenic
acidisn't readily absorbed, or is readily degraded, by our bodies.
Though grapes and kiwi both led to noticeable
spikes in plasma AOC, scientists haven't yet pinpointed which antioxidants were
responsible for the increases.
Further research may help establish national
guidelines that indicate the kinds and amounts of antioxidants we need for
optimal health.
For details contact
Ronald
L. Prior, (501) 364-2747; USDA-ARS
Arkansas
Children's Nutrition Center, Little Rock, Ark.
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When buying foods for kids, it's reasonable
to reach for those that feature extra nutrition information on the front of the
package. But foods in packaging that highlights, for example, "good source
of nutrient x, y or z" may also be high in saturated fat, sodium or added
sugar.
Check nutrient composition labels on kid-oriented
foodsbefore you buy.
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That was the case with more than half of the
kids' foods that ARS researchers based at the agency's Grand Forks (N.D.) Human
Nutrition Research Center noted when checking the shelves in six major
supermarkets in the area. In all, the researchers examined the packaging of
nearly 57,000 food items.
Some 60 percent of the 9,105 kid-oriented
foods that were packaged with nutrition informationnot just the
nutrient-content labelwere also high in one or more ingredients that can
contribute to health problems such as childhood obesity.
Those ingredients included saturated fat,
sodium or added sugar. Levels were compared to those recommended in the 2005
Dietary Guidelines for Americans.
Wise shopping decisions might help combat
childhood obesity. Almost nine million American children age six years or older
are obese.
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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Calcium and low-fat dairy foods may help fight
fat.
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Eating calcium-rich foods, including low-fat
dairy products, may have helped some young white males in the Bogalusa (La.)
Heart Study to form less abdominal fat than their study counterparts.
ARS-funded scientists at the Children's
Nutrition Research Center, Houston, Texas, and co-researchers from Tulane
University, New Orleans, La., analyzed foods and beverages consumed byand
various body-fat measurements of1,306 young adult male and female blacks
and whites age 19 to 38.
The intent? To determine if there was an
association between calcium, dairy foods, overweight and obesity.
Results showed that, for young white males
only, eating higher amounts of calcium-rich foodsincluding low-fat dairy
foodswas inversely associated with waist-to-hip ratio, a measure of
abdominal adiposity (Journal of the American College of Nutrition,
volume 25, pages 523 to 532).
Additional research may reveal why
weight-control benefits, attributed to calcium and low-fat dairy foods in other
studies, didn't occur in more of the Bogalusa volunteers. That information
could help the nearly two-thirds of American adults who are considered
overweight or obese.
For details contact
Theresa
A. Nicklas, (713) 798-7087; USDA-ARS
Children's
Nutrition Research Center, Houston, Texas.
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Watermelon is an excellent source of the amino
acid citrulline.
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Here's another reason to enjoy watermelon
before summer ends: This delicious fruit is unusually high in an amino acid
known as citrulline. Our bodies use citrulline to make yet another amino acid,
arginine, which helps cells divide, wounds heal, and ammonia to be removed from
the body.
Watermelon's citrulline seems readily
available for the body to take up and use. That's suggested in studies by
scientists currently or formerly at the ARS South Central Agricultural Research
Laboratory, Lane, Okla.
They did the work with co-investigators from
the ARS Henry A. Wallace Beltsville (Md.) Human Nutrition Research Center; the
ARS Citrus and Subtropical Products Research Laboratory, Winter Haven, Fla.;
and several universities, documenting their work in the journal
Nutrition (volume 23, pages 261 to 266).
Volunteers in the study completed one
three-week stint during which they drank about three eight-ounce glasses of
watermelon juice every day, and one three-week period of drinking about twice
that much of the juice daily.
For comparison, other volunteers neither
drank the juice nor ate watermelon or certain other foods that would skew study
results.
Blood levels of arginine, synthesized in the
body from the citrulline provided by the watermelon juice, were 11 percent
higher in volunteers tested after three weeks on the three-glasses-a-day
regimen (24 ounces), and 18 percent higher following the six-daily-glasses
regimen (48 ounces), when compared to levels in samples from volunteers who
didn't drink the melon juice.
Now, the scientists want to determine the
best way to extract citrulline from watermelon. Preliminary results of medical
researchdone elsewheresuggest that arginine might help treat high
blood pressure, unhealthy blood sugar levels and vascular disorders associated
with sickle-cell disease.
For details contact
Penelope
M. Perkins-Veazie, (580) 889-7395, ext. 267; USDA-ARS
South
Central Agricultural Research Laboratory, Lane, Okla.
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New lettuces shrug off attack by troublesome
microbes.
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Fresh, crunchy iceberg lettuces that boast
new resistance to some of their worst disease enemies may show up in
supermarket produce sections of the future.
Lettuce breeders at ARS' Crop Improvement and
Protection Research Unit, Salinas, Calif., lead the research, often
collaborating with university specialists.
More than a half-dozen vegetable seed
companies have requested seed of parent iceberg lettuce plants that the
scientists developed as the first-ever to resist attack by the microbe that
causes verticillium wilt. A lettuce lacking this resistance may collapse, like
a deflated playground ball, before it has a chance to form the familiar firm,
nicely rounded head (Plant Disease, volume 91, pages 439 to 445).
Lettuce is one of America's top-five most
popular vegetables. Iceberg lettuce outsells all other kinds of this versatile
leafy green.
The new parent plants join a long list of
other superb iceberg lettuces developed at the Salinas laboratory. That list
includes plants with resistance to the microbes that cause diseases named for
the symptoms they trigger, including lettuce mosaic, big vein and corky root
(HortScience, volume 42, pages 701 to 703).
For details contact
Ryan
J. Hayes or
Beiquan
Mou, (831) 755-2800; USDA-ARS
Crop
Improvement and Protection Research Unit, Salinas, Calif.
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New from ARSplump, white great northern
beans, like the ones shown here, that resist common bacterial blight.
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Great northern beansplump, nutritious
and faster to cook than many other bean typesmake a hearty baked-bean
entree as well as tasty chili, soups, salads and more. Now, a new great
northern bean named ABC-Weihing offers growers a special advantage: It resists
the microbe that causes common bacterial blight.
ABC-Weihing is among the first great northern
beans with that prized trait, according to the scientists who developed this
legume. They are based at ARS' Vegetable and Forage Crops Production Research
Unit, Prosser, Wash., the ARS Henry A. Wallace Beltsville (Md.) Agricultural
Research Center, Beltsville, and at the University of Nebraska.
Severe outbreaks of common bacterial blight
can cause yield losses of up to 40 percent.
Great northern beans are high in fiber and
protein, and are an important source of antioxidants and minerals, plus folate
and other B vitamins.
To accelerate the breeding of ABC-Weihing,
the researchers used marker-assisted selection, a technique that detects key
genes faster than most conventional plant-breeding tactics. An article in a
forthcoming issue of Crop Science tells more.
ARS scientists and university colleagues have
already boosted common bacterial blight resistance in several other popular
kinds of beans, including pinto and both white and dark-red kidney
beans.
For details contact
Phillip
N. Miklas (509) 786-9258; USDA-ARS
Vegetable
and Forage Crops Production Research Unit, Prosser, Wash.
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Flours of the future may be made from distillers'
dried grains. Tons of the grains pile up at this Midwest ethanol plant.
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Breads, pastas, cookies and other foods might
tomorrow be made with a perhaps-surprising ingredientflour milled from
distillers' dried grains, or DDGs. Right now, DDGsleft over after ethanol
is distilled from cornare accumulating in unprecedented amounts, a result
of the surge in U.S. ethanol production.
ARS scientists with the North Central
Agricultural Research Laboratory, Brookings, S.D., and co-researchers are
taking a new look at the old idea of using DDGs flour in place of some or all
of the wheat flour in familiar recipes. An array of foods low in calories and
carbsbut high in protein and fibercould result.
However, scientists must first discover a way
to prevent or remove the odors and off-flavors that develop in DDGs during
conventional ethanol production (Cereal Foods World, volume 51, pages 52
to 60).
Today's DDGs are used primarily as livestock
feed ingredients.
For details contact
Kurt
A. Rosentrater, (605) 693-5248; USDA-ARS
North
Central Agricultural Research Laboratory, Brookings, S.D.
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A sheet of gelatin, made from Alaskan pollock fish
skin, is flexible, versatileand edible!
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Clear, shiny, invisible coatings that you can
eat might provide a new way to make sure unwanted water vapor or oxygen can't
ruin the taste or texture of your favorite frozen foods.
Perhaps surprisingly, these wraps, which look
something like conventional plastic wraps for kitchen use, might be derived
from gelatin extracted from the silvery skins of seagoing fish such as Alaskan
pollock (Journal of Food Science, volume 71, pages E202 to E207).
In Alaska, skins left over after pollock and
other fish are processed into fillets are typically ground up and dumped into
the sea or processed into low-value fishmeal. Fish gelatin coatings may provide
a profitable and environmentally friendly alternative to dumping
The thin, pliable coatings that ARS food
technologists at the Western Regional Research Center, Albany, Calif., and
Subarctic Agricultural Research Unit, Fairbanks, Alaska, and their university
colleagues have developed and tested have no seafood taste or odor, despite
their marine origin.
Films made from fish gelatins aren't new. But
the ARS studies apparently are the first to establish the effectiveness of
Alaskan pollock gelatin as a barrier to unwanted moisture and oxygen. In fact,
the fish gelatin proved a more effective barrier than films made from the
traditional sourcescow and pig hides.
Another plus: The fish gelatin would be
acceptable in kosher and halal cuisines, while today's cow and pig gelatins are
not.
For details contact
Peter
J. Bechtel, (907) 474-2708; USDA-ARS
Subarctic
Agricultural Research Unit, Fairbanks, Alaska.
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Your microwave or dishwasher can make sponges
safer to reuse in today's kitchens.
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Heating your used kitchen sponges in your
microwave for one minute, or washing them in your dishwasher and leaving them
there through a drying cycle, are the most effective household ways to
inactivate harmful bacteria, yeasts and molds.
ARS food safety experts who specialize in
research on foodborne pathogens, like E. coli O157:H7, looked at several
simple, convenient and often-recommended ways of cleaning reusable kitchen
sponges. Techniques included soaking sponges for three minutes in a 10-percent
chlorine bleach solution, soaking in lemon juice or sterile water for one
minute, heating in a microwave at full power for one minute, or washing in a
dishwasherincluding through a drying cycle.
At the outset of the experiment, they soaked
all the sponges for 48 hours at room temperature in a slurry of ground beef and
laboratory compounds which allow bacteria, yeasts and molds naturally present
in the beef to grow on the sponges.
Microwaving and dishwashing each killed
nearly 100 percent of the bacteria, with dishwashing being only slightly
(0.0001 percent) less effective.
And, microwaving and dishwashing each killed
nearly all yeasts and molds; less than 1 percent (only 0.00001 percent)
survived.
For details contact
Manan
Sharma or
Cheryl
L. Mudd, (301) 504-8400; USDA-ARS
Henry
A. Wallace Beltsville Agricultural Research Center, Beltsville, Md.
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Love peppers?
There's still time to visit "A Pepper
for Every Pot," a special exhibit about the beauty, flavors and nutrients
in these fascinating plants.
ARS plant breeders who develop premier peppers
like Tangerine Dream provided expertise for a new U.S. Botanic Garden
exhibit.
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Allow at least a half-hour to view the
displays at the U.S. Botanic Garden's Conservatory, 100 Maryland Ave., S.W., in
Washington, D.C., now through November 12, 2007.
ARS is cosponsor of the exhibit, with agency
scientists from the Henry A. Wallace Beltsville (Md.) Agricultural Research
Center contributing pepper plants that they have developed. Superior peppers
from their research include Tangerine Dream, a sweet, edible ornamental pepper
that produces small, orange fruit on a flat, low-growing plant
(HortScience, volume 39, pages 448 to 449) and All-America Selection
award winner Black Pearl, which forms black leaves and small, hot, shiny black
fruit that ripen to a bright scarlet (HortScience, volume 40, pages 1571
to 1573).
For details contact
John R.
Stommel (301) 504-5583 or
Robert
J. Griesbach (301) 504-6574; USDA-ARS
Henry
A. Wallace Beltsville Agricultural Research Center, Beltsville,
Md.
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