Sanitizing and scrubbing does not remove contamination

by MM&D Online Staff

BRAMPTON, Ontario—A new series of independent studies from the Center for Food Safety at the University of Arkansas’ Department of Food Science show bacteria adheres and forms bio films, including Salmonella, Listeria and E. coli, on RPCs used to ship fresh produce, meats and eggs.

Salmonella often develops from eggs and proteins, and is the most costly foodborne illness according to the U.S. Department of Agriculture Economic Research, which is used as a foundation for analyzing food-safety policy.

Center for Food Safety research led by Dr Steven Ricke found that both commercial and industrial sanitizing and scrubbing methods such as hot water, alkaline detergent, quaternary ammonium and chlorine, could not eliminate biofilms. Ricke conducted three tests of RPCs as a platform for generating the bacteria biofilms of these common pathogens.

“Our research regularly looks at biological functionality to basic food safety implications from farm to fork; how pathogens form, how they transfer to food and how the consumer becomes exposed,” said Ricke.

Once formed and confirmed using Scanning Electron Microscopy (SEM), the biofilms grew and were then sanitized, using methods and agents typically found in commercial and industrial settings, including scrubbing.

In all cases, his research found that bacteria not only attached to the RPC, but also could not be dislodged by either sanitizers or physical scrubbing.

“The risk to a potential victim cannot be seen, as these biofilms are not visible to the naked eye,” said Ricke. “Plus, biofilms are resilient to cleaning, which makes them survive on surfaces and hide in cracks and crevices of the material in which they attach, so it all adds up to potential risk, even sustained risk, pending the exposure.”

To eliminate contamination risk, Ricke recommends shippers and retailers choose single-use packaging. While some retailers demand growers and packers use RPCs, others prefer corrugated.

Ricke along with several other food safety experts encourage retailers to follow the science and avoid risks identified in recent research involving RPC.

He concluded, “Every day, you can pick up a newspaper, turn on the television or read online about a new outbreak on a number of products involving U.S. food supply. Our job as experts in food science is to determine how to avoid those risks, and from what we know through research is 1) re-use is a source for contamination; and 2) cleaning or scrubbing does not eliminate biofilms; so this will continue to confront us.”

Dr Ricke is Director, University of Arkansas Center for Food Safety, and Wray Endowed Chair in Food Safety. He also is a faculty member of the Department of Food Science and the Cellular and Molecular Graduate program.