HOW LONG CAN I STORE EGGS?
Effects of Extended Storage on
Eggs
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ARS News Service
Agricultural Research Service, USDA
Sharon Durham, (301) 504-1611, sdurham@ars.usda.gov
June 2, 2004
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Egg quality and usefulness are safely maintained beyond the sell-by
date if the eggs are stored properly, according to Agricultural Research
Service scientists in Athens, Ga.
ARS food technologists Mike Musgrove and Deana Jones with the agency's
Poultry Processing and Meat Quality Research Unit tested the quality
and functionality of table eggs during a 10-week storage time, long
beyond the current 30-day industry standard for storing eggs on the
store shelf. Properly refrigerated and handled, eggs are considered
safe for consumption for four to five weeks beyond the sell-by date.
Musgrove looked at bacteria like Salmonella, Escherichia, Enterobacter,
Klebsiella and Yersinia that can contaminate eggshells and--if handled
or processed improperly--remain on eggs when they reach the consumer.
However, Musgrove found that after washing and packaging, eggs showed
no bacteria of the Enterobacteriaceae family until the fifth week
after processing. Washing eggs according to current guidelines removes
bacteria from their surface, reducing the chances of microbes getting
into the eggs once they are cracked in preparation for consumption.
An egg's shell and membranes under the shell provide a barrier that
limits the ability of organisms to enter. A natural protective coating,
called the cuticle, helps to preserve freshness and prevent microbial
contamination of the egg. This coating is damaged or removed by processing,
but a thin layer of oil may be applied during processing to help preserve
internal quality. The eggs are then placed in cold storage and shipped.
Jones studied the functionality of the eggs during 10 weeks of storage.
Eggs are found in a wide range of foods, including baked goods and
mayonnaise. Over time, eggs can lose their ability to fluff up an
angel food cake or make creamy mayonnaise, but according to Jones,
they didn't show a marked decrease in quality during the 10-week test
period.
Read more about the research in the June issue of Agricultural Research
magazine, available on the World Wide Web at:
http://www.ars.usda.gov/is/AR/archive/jun04/egg0604.htm
ARS is the U.S. Department of Agriculture's chief scientific research
agency.