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Quiz Show - Raw Eggs

Updated: Dec 2, 2021

The term 'TCS' is often used to refer to food requiring temperature or time control for food safety. So let the games begin and test your knowledge.

These eggs were found in the dry storage area with the mustard, catsup and burger buns. The time out of temperature was unknown and the eggs were discarded. Let's learn more about why we refrigerate raw eggs and why we can find them on dry goods section in other countries.

U.S. Department of Agriculture:

Prompted by concerns about spoilage and foodborne illnesses, U.S. egg producers and processors began washing and refrigerating their eggs in the early 1970s. Other countries soon followed suit, and eggs are now washed and refrigerated in Canada, Japan, and Scandinavia. But the approach has never caught on in most of the European Union, where eggs are neither washed nor refrigerated. They are kept at room temperatures, even in stores.

Eggs on a conveyor belt entering the washing system. (The American Egg Board, D3992-1)

The rationale is that a chicken egg is coated with a thin, protective “cuticle,” or membrane, that prevents Salmonella and other bacteria from penetrating the shell. Some Europeans argue that makes refrigeration unnecessary and that washing the egg washes away the cuticle.

The results were not surprising, because refrigeration is generally considered a cornerstone for maintaining the quality of so many fresh foods, states Deana Jones, an Agricultural Research Service (ARS) food technologist in Athens, Georgia. Moreover, previous research has shown that the cuticle degrades after the egg is laid, diminishing its protective effect. “We know that the cuticle dries and comes off, and we also know that from an evolutionary standpoint, it isn’t there to prevent Salmonella in the egg, but to control respiration during incubation,” she says.

The results showed that the refrigerated eggs, regardless of whether they were washed or oiled (mineral), were still Grade A quality after 15 weeks, on average, and that the quality of eggs stored at room temperature declined rapidly. In fact, unwashed eggs stored at room temperature degraded from Grade AA to Grade B in just a week, and they also lost 15 percent of their weight over the 15 weeks. Under refrigeration, the unwashed eggs lost the same amount of weight as the washed eggs. The study can be found here.—By Dennis O’Brien, ARS Office of Communications

“Candling” eggs to look for quality downgrades. The grade is based on qualities that can be observed in the shell, yolk, and egg white when the egg is inspected with lights. (Gerald Heitschmidt, D3995-1)

In America, food safety officials emphasize that once eggs have been refrigerated, it is critical they remain that way. A cool egg at room temperature can sweat, facilitating the growth of bacteria that could enter the egg through its porous shell.


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