Vitamin E, for Listeria-Free Turkeys
Researchers have found that adding vitamin E to poultry diets may reduce
incidence of Listeria monocytogenes, a major foodborne bacterial
pathogen found in poultry products. It causes listeriosis, a disease
that mainly affects pregnant women, newborns, and individuals with weakened
immune systems. In the United States, about 2,500 cases of human meningitis,
encephalitis, sepsis, fetal death, and premature birth are attributed
to L. monocytogenes annually.
Turkeys require vitamin E for normal development and immune system
function. Supplementing their diets with vitamin E has been found to
boost white blood cells, stimulating the birds' immune responses and
helping them clear L. monocytogenes from their guts. It also
enhances quality and shelf life of poultry meat. Scientists with the
University of Arkansas and Iowa State University have been cooperating
in this research. Testing of vitamin E against two other foodborne pathogens,
Salmonella and Campylobacter, is being planned.
Irene V. Wesley,
USDA-ARS National Animal Disease
Center, Ames, Iowa; phone (515) 663-7291.
What Next? Edible Adhesives!
That's right. And they can be readily made from sugar that's combined
with water and organic acids. Boiling makes the sugar and acids bond,
or cross-link, forming a dark-yellow adhesive. What's such an adhesive
good for? Well, it was developed by ARS
for use by a beverage packing company interested in a strong, fast-curing
adhesive that could bond drinking straws to a special holder that would
be placed in drink containers before filling and sealing. Then the bond
would dissolve in an even, controlled manner, so that the straw would
be free to rise when the beverage is opened.
Researchers chose sugar as an ingredient for this edible adhesive because
it's familiar, inexpensive, readily available, and already used in beverages.
They tried 10 different sugars and 12 organic acids. Tests produced
adhesives that bonded to cloth, glass, leather, metal, paper, plastic,
and other materials. When exposed to liquids, the adhesives dissolved
within 20 to 60 minutes, depending on the formulation. With several
other potential applications, these edible adhesives have been patented.
Sevim Z. Erhan,
USDA-ARS Food and
Industrial Oils Research Unit, Peoria, Illinois; phone (309) 681-6532.
Prebiotics as Intestinal Soothers
Each year, about 10 million Americans require hospital care for a variety
of gastrointestinal problems. In Europe and Asia, consumers are buying
prebiotic products formulated to boost populations of Bifidobacterium
bacteria and other microbial colonists of the human gut. Prebiotics
are complex carbohydratesoligosaccharides, such as inulin and
short-chain sugars. They pass, undigested, from the lower intestine
to the colon, where beneficial bacteria consume them, releasing vitamins,
minerals, and nutrients. They may also curb the growth of food pathogens
such as Salmonella by changing the colonic environment.
An enzyme-based process for making alternana promising potential
bulking agent for low-calorie, high-fiber foodshas also yielded
oligosaccharides that stimulate growth of Bifidobacterium. A
patent is being sought to cover the synthesis and potential use of some
of the prebiotics as food and feed additives.
Gregory L. Cote,
USDA-ARS Fermentation Biotechnology
Research Unit, Peoria, Illinois; phone (309) 681-6319.
Soy Bread Would Put More Protein in Your
Taste is what's kept many consumers from buying soy-based breads, but
an improved dough formulation may change that. It will let bakers use
soy flour to enrich the protein content of bread while minimizing its
beany aftertaste. All it took was finding the right ratio of defatted
soy flour to whole- and white-wheat flour. Researchers also added different
amounts of ascorbic acid, salt, sugar, milk, water, and vegetable shortening,
along with active dry yeast. They found that the yeast, plus extra sugar
and ascorbic acid, significantly reduced soy's beany aftertaste.
Trained taste panelists have judged the soy-enhanced breads and found
them comparable to all-wheat breads, though slightly more dense. But
loaves made with 30-40 percent soy flour contain 112-127 grams of protein,
compared to 65 grams for wheat bread. Plus, they meet recommended daily
values for protein, fat, and carbohydrates and are naturally high in
total dietary fiber and heart-healthy compounds such as isoflavones.
Soy bread could be baked commercially for about 50 cents a loaf, making
it especially useful in food-assistance programs.
Randal L. Shogren,
USDA-ARS Plant Polymer Research
Unit, Peoria, Illinois; phone (309) 681-6354.
"Science Update" was published in the August
2004 issue of Agricultural Research magazine.