of washers in poultry processing
A four-year drought and
a steadily dropping aquifer have made water a precious commodity in
Eastern North Carolina. At the same time, new food safety regulations
have boosted water usage by 30 to 50 percent at many poultry processing
plants.
Researchers in the College
of Agriculture and Life Sciences have found that additional washers
don’t have much effect in removing Campylobacter bacteria, one
of the leading causes of foodborne illnesses.
Since 1998, federal regulations
have required poultry processors to increase the number of washers in
their plants to make sure poultry carcasses are clean. Historically,
plants have used two to three washer systems on a line, but now have
added three to four additional washers. An average poultry processing
plant uses 1 million to 2 million gallons of water each day.
The new Hazard Analysis
and Critical Control Points, or HACCP, regulations are designed to create
a safer food product by identifying critical points in food processing
where contamination can occur. While there have been some studies of
how well the washers remove other types of foodborne bacteria, no one
has really investigated how well they remove Campylobacter.
Dr. Kevin Keener, an N.C.
State Extension food scientist
and process engineer, and graduate student Mike Bashor examined poultry
carcasses at different points in processing plants. They discovered
that additional washers did little to reduce the incidence of Campylobacter.
“They’ve put additional
washers in (processing lines) because they think they’re helpful.
We found that with Campylobacter, washers really don’t have much
impact,” Keener says.
Campylobacter is said to
be one of the most frequent sources of foodborne illness in people and
a leading cause of death from such illness, says Keener. Poultry products
are a major source of the disease-producing bacteria.
The researchers found that
eight of every ten poultry carcasses were positive for Campylobacter.
Though the organism can be killed through proper cooking, it can survive
refrigeration and even freezing temperatures in some cases. The poultry
carcasses are contaminated with the bacteria during processing.
Keener and Bashor worked
with four poultry processing plants in North Carolina and Alabama to
determine if the washers are effective at removing Campylobacter. Other
researchers involved with the project include N.C. State’s Brian
Sheldon, a poultry scientist, and Dr. Sophia Kathariou, a food scientist,
Dr. Jason Osborne, a statistician, and Dr. Pat Curtis of Auburn University.
A variety of washers are
used in processing, ranging from those that spray the outside of the
carcass to those that spray inside and outside. Some washers use brushes,
and others use antimicrobial agents such as chlorine, trisodium phosphate
and acidified sodium chlorite, Keener said.
A positive poultry carcass
has around 50,000 Campylobacter organisms, and the researchers found
that all the plant washers combined reduced the number to only about
25,000. Since as few as 500 organisms can cause illness, the washers
don’t significantly reduce the risk of disease from Campylobacter
contamination.
Antimicrobial rinses are
more effective, Keener said, reducing the number of organisms from 50,000
to 5,000 per carcass. Even this reduction is not enough to prevent illness,
he said, and such treatments are more expensive to use.
“Our study found that
the current level of washing isn’t going to be sufficient to control
Campylobacter,” Keener said.
Water-use restrictions,
water-quality regulations and proposed restrictions on plant effluents
make it critical for plants to use the most efficient carcass washing
systems. Plants visited by the researchers used an average of 0.6 gallons
to 2.4 gallons of water per carcass during washing.
Yet the researchers found
no significant difference in the number of Campylobacter organisms based
on the amount of water used. While some water is necessary to rinse
the birds, Keener said, 2.4 gallons per bird is excessive.
“Increased water doesn’t
help,” Keener said. “Additional intervention methods, besides
washing, will need to be developed if processing plants are going to
reduce Campylobacter levels on raw poultry.”
The study involved collecting
poultry carcasses before and after entering washing systems. The carcasses
were transported back to N.C. State, packed in ice and examined to compare
bacteria counts before and after washing. Though the researchers compared
pathogen levels in fall and summer, they did not find a significant
difference.
Keener said the research
provides the industry and regulators with valuable information. The
U.S. Department of Agriculture, which
inspects poultry plants, may be moving toward proposed performance standards
for Campylobacter on poultry carcasses in processing plants. Such standards
would dictate acceptable levels of these bacteria for poultry carcasses.
Information from this study
will demonstrate for USDA the effectiveness of the current system for
reducing Campylobacter and the need for alternative treatment strategies
and technologies to control the bacteria, he said. “This study
will allow plants to look at how they can improve the effeciency of
their washers,” he said.
The research was funded
by the U.S. Poultry and Egg Association,
which will release a report on the work. Finding new and better ways
of removing Campylobacter from poultry carcasses should help processors
save water and improve food safety.
—Natalie
Hampton
