Researchers zap microbe DNA in the name of food safety

Researchers are gauging the effectiveness of electron beams in the fight against foodborne illness pathogens in poultry.

At the heart of a new study published in Poultry Science, is eBeam, a non-thermal technology that uses high-energy electron beams that cause irreparable damage to pathogen DNA.

Foodborne illness

Foodborne illness is no small thing. The U.S. Centers for Disease Control and Prevention said it typically coordinates 17-36 investigations of foodborne illnesses each week. In a study, the CDC said that seven foodborne pathogens accounted for 53,300 hospitalizations and 931 deaths in 2019 alone.

Along with X-rays and gamma rays, eBeam is approved by the U.S. Food and Drug Administration for “cold pasteurization” — a germ-killing technique that doesn’t rely on heat. X-rays, gamma rays and electron beams have been used for decades “for pathogen control in fresh, frozen and refrigerated food,” said Palmy Jesudhasan, a research microbiologist at the U.S. Department of Agriculture’s Agricultural Research Service.

Currently, irradiated fruits and spices are on grocery shelves, and Omaha Steaks and Schwan’s use irradiation to pasteurize beef, Jesudhasan said. However, the technology’s use in “poultry still lacks the data to build confidence” in its use. “We started with ground poultry because it is a major source of salmonella and campylobacter and a key driver of recalls,” Jesudhasan said.

The study had dual goals: First, understand the ability of eBeam technology to reduce or control food pathogens, and second, evaluate the effects of irradiation treatment on meat quality, he said.

How eBeam works

The research team used the world’s largest electron beam irradiator at the National Center for Electron Beam Research, housed at Texas A&M University.

“eBeam is mainly used for sterilization purposes,” Jesudhasan said. “When you expose any cells, whether it’s human cells, bacterial cells, or virus to the beam, it hits the nucleus and shreds DNA or RNA so bacteria cannot replicate.”

While it can halt bad bacteria, the beam can induce other effects. Jesudhasan said the process “could also generate other reactive oxygen species that can also cause not-so-good side effects for the bacteria.”

What about the flavor?

The trick is finding the right dose. “We don’t want to use too much of a dose,” Jesudhasan said. “When you use too much, it might make the product bad.”

While the electron beam doesn’t heat or cook the meat, its oxidizing qualities bear watching, especially in poultry, said Casey Owens, professor and meat scientist for the University of Arkansas Division of Agriculture. “You’ve got to do the meat quality testing, because the oxidation is really the main thing that can start changing quality,” she said.

Poultry’s higher levels of unsaturated fats make it more susceptible to oxidation. “Oxidation breaks down fats, and the degradation of those fats causes off-flavors and off-odors,” Owens said. “Think about leftover holiday turkey. The next day it has what some people call a ‘warmed-over’ flavor - That’s mild oxidation.”

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Jesudhasan said the research found differences in how the electron beam affected turkey versus chicken. The turkey used in the study was in modified atmosphere packaging, or MAP. In this type of packaging, the ratios of oxygen, carbon dioxide and nitrogen are adjusted to slow oxidation. “When turkey was in MAP, everything there looked good,” he said. “We were able to inactivate pathogens and we were able to show meat quality was preserved.”

“The only difference we found is in chicken meat that had the off note,” Jesudhasan said.

The authors write that using eBeam “offers a promising intervention strategy to enhance microbial safety while minimizing heat-induced changes in meat quality.”