Visit any grocery store and you can expect that the produce, meat and other products that line the shelves are not contaminated.
But sometimes that’s not the case.
Each year the federal government launches dozens of investigations into foodborne disease outbreaks traced to germs like salmonella, listeria, E. coli and others. The Centers for Disease Control and Prevention estimates 48 million people fall ill annually as a result.
And of those who get sick, 128,000 are hospitalized and 3,000 die.
Salmonella is one of the top germs that causes these ailments, and it’s a pathogen often associated with chicken and eggs. A research team led by the University of Missouri is responding by developing ways to more quickly detect the pathogen in the entire chicken supply chain. (The University of Missouri-St. Louis, Lincoln University, Auburn University and the University of Notre Dame also are involved in the research.)
“We just want to make a safe food supply for everyone,” said Kate Trout, one of the project’s principal investigators at the University of Missouri. “(Including) rural communities, low income communities, which we now have higher rates of salmonella infections.”
Trout explained the research aims to take the results from sensors that rapidly detect small amounts of salmonella and pair them with data on food production, animal health, population health and other geospatial data.
That lines up with the U.S. Department of Agriculture's goals for mitigating salmonella in the food supply, she added.
Saving resources and time
While the chicken supply chain is relatively safe with few notices of contamination, experts say the current testing process often takes several days.
“People are constantly looking for better ways to sample, better ways to test and get faster results,” said Jim Dickson, a professor in Iowa State University’s animal science department. “The quicker a processor gets results, the quicker they can react to them.”
The USDA Food Safety and Inspection Service tests for the bacteria, and major poultry processors also typically test their chicken every day too, he said. But testing laboratories are often off-site, and preparing a sample before it can be tested can take a day or two.
“Realistically, in most cases we’re talking about three days from the time of the sample to the time of the result,”Dickson said. “By the time they get results back that product is gone. It’s already been shipped.”
The team’s research, funded by the National Science Foundation’s Convergence Accelerator, addresses the issue of timing by developing new portable and easy-to-use sensors that can quickly detect small amounts of contamination.
“One that allows us to do testing basically within one hour,” said Lead Principal Investigator Mahmoud Almarsi. “The second one, the optical one, we are testing within 10 minutes and probably even lower than 10 minutes.”
Almarsi, a professor in Mizzou’s electrical engineering and computer science department, added they’re also creating a third sensor that will be able to detect the specific kind of salmonella present in a sample.
“There are maybe 2,500 different types of salmonella,” Almarsi said. “But not all of them are in poultry.”
This level of granularity would go further than the current industry standard, which only detects salmonella in general, said Kantha Channaiah, an assistant professor of food science at Mizzou.
“This is going to play an important role in saving a lot of resources and time,” he said. “For industries, for commercial manufacturers, time is money.”
Plus, the science behind the separate sensors can work on other bacteria, like listeria, E. coli or staph, Channaiah said.
“We can apply this principle and concept and we can extend the scope of this technology to other pathogens assuring safety,” he said.
Testing throughout the supply chain
Figuring out just which biosensors work best and where to place them within the entire chain—from the farm to the table—is a big part of the research effort.
“Having the biosensor developed is not the end of the question. That is not enough,” said Haitao Li, another principal investigator, and supply chain analytics department chair at the University of Missouri-St. Louis.
Li is developing a mathematical programming model to help decide which of his colleagues’ sensors are best suited for a specific company’s needs. The model can also help predict where to place the sensors at nodes in the vast poultry supply chain, he said.
A node can represent a facility, like a farm, or a process, like transportation or storage, Li said. And it can be very granular, like different steps in chicken processing — carcass washing, defeathering, cutting, packaging or other steps, he added.
Right now, chicken is only tested for contamination at the processor and there’s an assumption it will stay properly cold afterward, said Tim Safranski, a professor at Mizzou’s animal science research center.
“If the cold chain is maintained, it remains safe. If it’s properly cooked afterward, it would remain safe,” he said. “But there’s lots of opportunities along the way where things might not work correctly.”
But with sensors at many more points in the production chain, Li said the researchers can begin to build a real-time picture of the presence of salmonella in specific parts of the chicken supply. Chicken processors, companies that ship poultry products, grocers and government agencies could also get access to this information, he added.
“If we know the level of contamination risk, we might speed up the shipment of some goods or shorten their storage time,” he said. “We might issue a recall, we might redistribute some of the product depending on the market demand or the need of different population groups.”
Future applications
Some in the food distribution chain, like Carlton Adams, see the sensors potentially revolutionizing their business practices. Adams is the chief operating officer of Operation Food Search, which distributes donated food to dozens of agencies in eastern Missouri and southern Illinois that help combat food insecurity.
It’s imperative to him that the food they distribute to food pantries is high quality, dense with nutrition and reliable for the people who depend on it, Adams said.
“This notion that you don’t deserve to have good food, because you didn’t get straight A’s in capitalism, that’s crazy,” he said.
The new sensors and software could help Adams’ organization know more about the food it receives from its donors, which include large grocers, like Schnucks and Dierbergs, he said.
Plus, the sensors could help Operation Food Search throw away less food in case something goes wrong at their St. Louis facility, Adams said.
“Things happen. If we have a power outage, if the generator doesn’t kick in and we lose cold storage for a period, that food goes into the landfill,” he said. “That’s much less food that’s distributed to the community.”
With rapid and easy-to-use sensors that could check for contamination, it’s possible some of that food may not need to be thrown away, Adams added.
But this potential is likely several years away.
The research team is submitting a proposal for the next phase from the NSF to be reviewed later this year, as well as seeking feedback from potential investors, program managers and researchers from other funding agencies, Li said.
“This is a long-term, multi-year effort,” he said. “It’s not always easy, but I truly enjoy it.”
This story was produced in partnership with Harvest Public Media, a collaboration of public media newsrooms in the Midwest. It reports on food systems, agriculture and rural issues.
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