The Center for Produce Safety has awarded funding to researcher Paul Dawson, Ph.D., with Clemson University, to examine the potential pathogen contamination risks from dry surfaces in packinghouses, something few studies have looked at.

Dawson chose to examine the survival of Listeria monocytogenes and Salmonella on dry surfaces in lab-simulated peach packinghouses. These two pathogens have been found in packinghouses and have different physiologies.

To start, the researchers simulated a packing facility within the laboratory using coupons, or disks, cut from dry surfaces within a packinghouse. They then collected surface swab samples every two weeks from two California Central Valley peach packinghouses so the researchers could use organisms found in naturally occurring biofilms.

Dawson said that the initial data suggests that microorganisms have several mechanisms to adapt to dry conditions. The long survival intervals for dried Listeria and Salmonella biofilms also emphasize the importance of cleaning and sanitizing dry areas to prevent microbial attachment and biofilm formation.

The researcher’s next step is to evaluate a number of approved food-grade sanitizers’ effectiveness under lab-simulated dry packinghouse conditions. Dawson hopes the results will help identify management practices to reduce pathogen presence in a dry environment.

“Overall, we’re looking to improve product safety and quality by finding the problem areas in the last parts of the process that may have been overlooked in the plant after washing, waxing, and drying,” Dawson said. “Those may be critical areas. By targeting them and determining the survival of the pathogens, we can make the product safer.”

The full project abstract can be found here.

about CPS
The Center for Produce Safety is a 501(c)(3) nonprofit organization. CPS is a collaborative partnership that leverages the combined expertise of industry, government, and the scientific and academic communities to focus on providing research needed to continually enhance food safety. This level of collaboration allows CPS to fill the knowledge gaps on produce food safety and address both research priorities and immediate industry needs.