Salmonella enteritidis. Click the image for more information about it.
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Cool-Water Wash for Eggs Can Help Prevent
Microbial Contamination
By
Sharon Durham December 19, 2006
Using cooler water to wash shell eggs during a second washing can help
cool them quicker. This reduces the potential of foodborne pathogen growth both
inside the eggs and on the eggshell surface, according to scientists with the
Agricultural Research Service (ARS).
ARS food technologists
Deana
Jones and
Michael
Musgrove in the agency's
Egg
Safety and Quality Research Unit at Athens, Ga.working with
Auburn University colleagues A. Brooke
Caudill and Patricia A. Curtislooked at the frequency of Salmonella,
Campylobacter, Listeria and other bacteria in eggs commercially washed in
cool water. Their findings have been reported in the Journal of
Food Safety.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.
Currently, processors who choose to produce eggs that qualify for the
USDA quality shield are required to wash them in water that is at least
90°F, or 20 degrees warmer than the warmest egg entering the processing
line. Furthermore, these eggs are required to be sprayed with a sanitizing
rinse at least as warm as the wash-water temperature. To prevent the growth of
potential foodborne pathogens associated with eggs, these warm eggs must then
be cooled quickly for storage.
To ensure the eggs are safe for human consumption, USDA requires that
all shell eggs be stored at 45°F or lower after processing. That's because
Salmonellathe organism most often associated with foodborne
disease and eggsand other bacteria don't grow well at refrigerated
temperatures. Getting to the target temperature quickly can make a big
difference.
The researchers tested three water-temperature schemes in commercial
dual-washer systems: water at 120°F for both washers; water at 120°F
for the first wash and 75°F for the second; and both washers at 75°F.
They found that using a warm temperature in the first washer, followed by a
cool temperature in the second one, could provide the greatest benefit in terms
of both reduced egg temperature and acceptable microbial levels.
While Salmonella, Campylobacter and Listeria were all
detected in shell emulsion and wash-water samples from cool-water washing
treatments, none were detected in the egg contents throughout the storage
period of eight weeks.