University of Arkansas faculty and staff work to ensure consumer food products are safe for all.

Whether you’re a producer, processor, chef or consumer, food safety is for everyone. Everyone eats and makes daily decisions about what they’re putting into their bodies. But how do you know the items stocked on your grocery store’s shelves are free from contaminants? Those are questions best answered after learning more about food safety from the faculty and students who make up the Arkansas Center for Food Safety.

“The center serves the needs of Arkansans – and beyond,” explains center director Kristen Gibson, a professor of food science in the Dale Bumpers College of Agricultural, Food and Life Sciences and with the Arkansas Agricultural Experiment Station, the research arm of the U of A System Division of Agriculture. The faculty involved with the Center for Food Safety answer media inquiries, write collaborative grants to address important food safety issues and work with industry partners.

From greens to grains – and the spices you use to season them – Gibson and her colleagues can provide safety through their numbers (and research) to educate the next generation of food scientists, as well as the general population.

PRODUCE PATHOGENS

Gibson’s work centers on fresh produce, which is why she’s often contacted when there’s an outbreak associated with E. coli or norovirus. She examines food handling and safety all the way from field to packing and can recommend best practices for cleaning, sanitation and handling. (Hint: always, always wash your hands). Her research interests are focused on understanding the fate and transport of pathogens including bacteria, fungi, viruses and other harmful germs within the environment, optimization methods for the detection of viral pathogens in food and water and on environmental surfaces and food safety at the retail and consumer level.

“There are a lot of pathogens to be concerned about,” states Gibson, who mentions E. coli, Salmonella and Listeria as three of the most feared culprits. “In the consumer’s hands, there’s not a lot you can do when you get a contaminated food product, right? And it really depends on the product. If it’s fresh produce that doesn’t get cooked, there’s nothing you can do.” Washing your produce, while a good practice to follow, really won’t do anything to help something that’s already been contaminated by these pathogens. (Although she notes that sometimes bacteria can be attached to dirt, so it’s never a bad thing to give your produce a rinse.)

Often, the problem of contamination runs deeper – in the soil – or, in the case of the hydroponic greens Gibson studies, in the recirculating systems surrounding the plants. Her niche, in fact, is leafy greens, and she and her students examine pathogen localization and try to determine where they end up.

“We’re examining, over time, how these pathogens remain in the nutrient solution,” she explains. “Are they going to the roots? Are they ending up in the edible portion of the plant? There are a lot of different components to hydroponics and we’re looking for the potential to apply an intervention or a preventative control step.”

CUTTING CONTAMINATION

Jennifer Acuff approaches food safety from a holistic perspective and wants her work to be applicable to fellow researchers, food processors and – of course – consumers. She is an assistant professor of food microbiology and safety in the Bumpers College and a researcher and scientist with the experiment station. Acuff also serves communities and the food industry through the Division of Agriculture’s outreach arm, the Cooperative Extension Service.

Acuff works primarily on low moisture food products – things like dried fruits, nuts, spices and powders, like powdered milk.

“Food is never going to be sterile; it will never be risk-free,” she says. “We wouldn’t like sterile food – it wouldn’t taste very good, to be honest. But it’s important to know what the risks are, so that you feel in control and in power.”

Acuff received a grant to work on a project to investigate Salmonella contamination in dairy powders – an especially timely topic given the infant formula recalls that have occurred over the last decade.

“If pathogens manage to contaminate the food product in that desiccated environment – that lack of water, lack of moisture – they can survive for extended periods of time, and it can be very difficult to remove them from the foods,” she says. “It’s difficult to find interventions that can reduce contamination problems that occur, as we saw with the infant formula outbreak.”

Acuff and her students are trying to determine if there is a thermal process that involves a temperature low enough to not degrade the quality of the powder but is still effective at inactivating pathogens like Salmonella.

“Are the processes that are sufficient in deactivating the pathogens also going to be acceptable for consumer quality? That’s what we’re trying to find out,” she says.

One of Acuff’s most recent studies looked at sanitizing pecans for consumption, particularly against the likes of Shiga toxin-producing E.coli, or STEC.

“Growing and harvesting pecans in open environments provides the potential for cross-contamination of foodborne pathogens,” Acuff notes. Fecal matter from wildlife and livestock represent the potential contamination sources.

Her study found that a hot water treatment significantly reduced STEC from pecans and prevented cross-contamination and that lactic acid and chlorine treatments effectively maintained the wash water quality.

Erin Ramsay, a recently graduated food science master’s student, was the first author of the study with Acuff, and their findings were published in the Journal of Food Protection.

POST-HARVEST PROCESSING

Though many people may not associate Arkansas with pecan production, most do recognize rice as one of the state’s top commodities. According to data from the USDA’s National Agricultural Statistics Service, Arkansas is the nation’s leading rice producer, accounting for approximately 50% of all U.S. rice production each year.

Griffiths Atungulu knows that every grain of rice can make a difference – both to our state and the world. So, as a professor in the food science department for the Bumpers College and the experiment station and director of the experiment station’s Arkansas Rice Processing Program, he examines the post-harvest processing of rice to ensure the greatest possible quality throughout the grain drying, milling and storage processes.

“We are here for the bigger picture of trying to help the rice industry,” he says. “A lot of my research really has focused on what we can do from a post-harvest standpoint to improve the process of drying and milling. With rice, the process of removing that moisture looks simple, but it’s very different from other grains.”

Most rice is consumed as a whole kernel, so when moisture is removed, the rice may remain whole or it could break. When it breaks, the value of the rice drops almost 60%. That’s a big deal when rice is the staple food for 50% of the global population.

“Not every state is fortunate enough to grow the kind of rice we cultivate here in Arkansas,” Atungulu says. “We are truly blessed with the unique combination of soil types and environmental conditions that support our diverse rice cultivars. Each grower in Arkansas plays a vital and special role in strengthening not just our national food supply but also contributing to global food security.”

Atungulu is also involved in an ongoing project funded by the NC-213, a project team from leading U.S. land-grant universities and government research centers, to develop safer ready-to-eat rice products, such as instant rice. One of his doctoral students, Faith Ouma, is focused on eradicating the risk of potentially fatal aflatoxins from rice through safer storage methods.

When exposed to poor storage conditions, such as high temperatures and humidity, rice can become contaminated with fungi. Fungi can then produce naturally occurring toxic compounds called mycotoxins. Aflatoxins, a family of mycotoxins, are poisonous compounds that have been designated by the International Agency for Research on Cancer as Group 1 carcinogens, meaning there is sufficient evidence they can cause cancer in humans. Aflatoxins also pose a greater risk to children by threatening their immune systems and growth. Atungulu notes that once the toxin has been formed, the grain becomes almost useless.

Atungulu, Ouma and fellow researchers set out to determine how to prevent aflatoxin formation by measuring how temperature, humidity, storage time and moisture impact the toxin’s growth. Their work centered on crops grown in Hazen, Arkansas, demonstrating how research in the natural state is then applied to other countries around the world.

Atungulu says, “As a research team, we are honored to be part of the rice value chain – advancing research and outreach that provide our growers with access to the best post-harvest practices, while also training students who go on to support and strengthen the rice industry’s workforce.”

ASK AN EXPERT

The Arkansas Cooperative Extension Service is a great resource to learn more about food safety or ask individual questions. Arkansans can find their local county extension agent online.

For additional information about any number of food safety topics, reach out to one of the many experts from the Center for Food Safety. Working professionals are also encouraged to learn more about the online Master of Science in Food Safety program.