Jiyoon Yi, a postdoctoral researcher of biological and agricultural engineering, is this year’s Kinsella Memorial Award recipient for her research into preventing cross-contamination of surfaces at produce processing sites.

The award recognizes a graduate student whose Ph.D. dissertation is of high quality, original, involves more than one field of study and is important to the mission of the College of Agricultural and Environmental Sciences. The prize was established in 1994 to honor the late CA&ES Dean John Kinsella, who was a widely recognized food science and technology professor.

Yi, who grew up in Seoul, South Korea, and the United States, called the award a great honor that shows support for her research path.

“It’s a huge thing for me,” Yi said. “[Kinsella] was an internationally renowned professor. He’s not physically with us anymore but he’s providing long-standing support for my research.”

Each year, graduate groups nominate one student for the award. Yi’s research, teaching style and involvement with campus groups led to her selection, Professor Maria Marco, who chairs the Food Science Graduate Group, wrote in her nomination.

“Jiyoon’s research encompasses theoretical and empirical data, requiring skills in food processing, microbiology and mathematics…,” Marco wrote. “Her dissertation addressed critical needs in food safety research and demonstrated her mastery of the subject.”

Preventing outbreaks

Foodborne diseases can cause nationwide outbreaks and Yi analyzed contaminating microbes including E. coli  and Listeria for her research. Her dissertation centered on understanding bacterial transfers and developing ways to prevent cross-contamination.

“We really want to reduce the amount of chemicals and water used in the processing facilities to minimize economic and environmental burden,” Yi said.

She first analyzed cross-contamination between fresh produce – such as lettuce – and food contact surfaces in processing sites. She then developed antimicrobial surfaces bound with chlorine or food-safe coatings and measured their effectiveness.

Next came developing mathematical models to analyze the best way for chlorine to target only the biofilm, which are bonded bacterial communities attached to surfaces. “Our goal is to have the chlorine just kill target bacteria and minimize reactions with other parts,” she said.

She then used modeling to examine how the composition or topography of lettuce leaves could prevent antimicrobials from targeting microorganisms. “We found bacteria hiding in micro valleys of leaves, and chlorine could not reach them since they are consumed by reactions with plant organic matter,” Yi said.

She published five papers related to her dissertation and two additional papers are pending. Yi did her research in the lab of Nitin Nitin, a professor of food science and technology and biological and agricultural engineering.

Focus on food safety engineering

Yi enjoys teaching and being involved with campus groups.

“In addition to research, I would love to teach and participate in outreach and professional development activities for students,” she said about her future career plans.

She volunteered with the Center for Produce Safety’s professional development program, helped establish the student board within the Society of Food Engineering and was elected to the International Association for Food Protection’s student board.

Yi, whose dissertation was entitled “Novel Antimicrobial Compositions and Mathematical Models for Reducing Microbial Contamination of Fresh Produce and Food Contact Surfaces,” will receive a $3,500 award.