Kevin Keener, associate professor of Purdue University in Indiana, said the rapid cooling of eggs after laying and processing would “significantly reduce the ability of Salmonella to grow inside the egg and potentially keep consumers from becoming sick”.
A newly developed rapid cooling system uses carbon dioxide to create a thin layer of ice on the inside of the shell that will cut the risk of Salmonella illnesses as well as extend an egg’s shelf life.
During the recent recall of at least a half billion eggs, Keener noted that “natural contamination” from shell eggs is somewhat rare and more likely to have arisen because of sanitation issues in the processing plant.
“There is a big discussion right now about how food safety in the US is regulated and cooling eggs is part of that debate,” he told Food Production Daily.
According to Keener, under current industry practices, it takes up to six days to cool eggs to 45 degrees F, the temperature at which Salmonella can no longer grow.
“The eggs in the middle of a pallet may take up to six days to cool, and if the one in 20,000 that has Salmonella is in the middle, the bacteria will grow,” Keener said. “In reality, some eggs don’t cool to 45 degrees until they’re in the refrigerator in your home.”
The rapid cooling system Keener and his colleagues have been working on at Purdue takes only 90 seconds to cool eggs.
“Studies from the Food and Drug Administration show that if eggs were cooled and stored at 45 degrees or less within 12 hours of laying, there would be an estimated 78 percent fewer Salmonella illnesses from eggs in the United States each year,” he added.
Keener hopes the practice will be adopted by the industry and is looking for a commercial partner to help with this. In addition to costing only about 2 to 5 cents per dozen, the treatment will not slow down production.
Also, “the technology extends shelf life from the basic 6-8 weeks to 12-15 weeks depending on how the eggs are stored,” said Keener. “This extension would make the process commercially viable as the shelf life would be such that producers would have the potential to export.”