Sandwich cookies and sandwich crackers
The researchers focused on cookie and cracker sandwiches, putting the Salmonella into four types of fillings found in cookies or crackers and placing them into storage.

GRIFFIN, GA. — Researchers at the University of Georgia have found that pathogens, like Salmonella, can survive for at least six months in cookies and crackers. Their findings were published in the Journal of Food Protection.

Larry Beuchat, a Distinguished Professor Emeritus and researcher in the U.G.A. College of Agricultural and Environmental Sciences, led the study. Dr. Beuchat, along with study co-author David Mann, a research professional, sought to see how long bacteria that cause foodborne illness are able to survive in certain foods.

“There have been an increased number of outbreaks of diseases associated with consumption of contaminated dry foods,” said Dr. Beuchat, who works with the Center for Food Safety on the U.G.A. campus. “We wouldn’t expect Salmonella to grow in foods that have a very dry environment.”

Dr. Beuchat and Mr. Mann found that not only can harmful bacteria survive in dry foods, like cookie and cracker sandwiches, but they also can live for long periods of time.

As part of the study, the researchers used five different serotypes of Salmonella that had been isolated from foods involved in previous foodborne outbreaks.

“Isolates were from foods with very low moisture content,” Dr. Beuchat said.

The researchers focused on cookie and cracker sandwiches, putting the Salmonella into four types of fillings found in cookies or crackers and placing them into storage. The researchers used cheese and peanut butter fillings for the cracker sandwiches and chocolate and vanilla fillings for the cookie sandwiches.

These “are the kind that we find in grocery stores or vending machines,” Dr. Beuchat said.

After storing, the researchers then determined how long Salmonella was able to survive in each filling. Dr. Beuchat said there was survival in all types, but Salmonella survived longer in some types of the fillings than in others.

“The Salmonella didn’t survive as well in the cracker sandwiches as it did in the cookie sandwiches,” he said. In some cases, he said the pathogen was able to survive for at least six months in the sandwiches.

“That was not expected,” he said.

The ability of pathogens to survive in certain settings has researchers considering the next steps for preventing contamination and outbreaks they may cause.

“The next steps would be to test all ingredients that are used in these foods,” Dr. Beuchat said.