Tests show salmonella, listeria and E.coli exist on RPCs for fresh produce, meat & eggs

Reusable Packaging Association calls for ‘extreme caution’ on biofilm research

By Jenny Eagle contact

- Last updated on GMT

The University of Arkansas department of Food Science
The University of Arkansas department of Food Science

Related tags: Bacteria, Foodborne illness

The Reusable Packaging Association has called for ‘extreme caution’ on research by the University of Arkansas, which claims bacteria forms biofilms, including salmonella, listeria and E.coli, on reuseable plastic containers (RPCs) used to ship fresh produce, meats and eggs.

The research was led by Dr Steven Ricke of the Center for Food Safety at the University of Arkansas department of Food Science.

Industrial sanitizing & scrubbing cannot erase food contamination

Dr Steven Ricke

He found both commercial and industrial sanitizing and scrubbing methods such as hot water, alkaline detergent, quaternary ammonium and chlorine, cannot erase food contamination risk with RPCs.

The risk to a potential victim cannot be seen, as these biofilms are not visible to the naked eye​,” said Dr. 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​.”

But, Jerry Welcome, president, Reusable Packaging Association, told FoodProductionDaily, since they were introduced 25 years ago, RPCs have never been associated with foodborne illnesses. 

The results of the University of Arkansas study should be met with extreme caution​,” he said.

A thorough examination of the methodology is necessary. In addition, laboratory testing of this nature often fails to replicate results once the methods are exposed to real world conditions related to the cleaning, sanitation and use of RPCs​.

It is important to note many of the recent studies on RPC safety have been funded and/or promoted by the cardboard container industry in an attempt to cast doubt on RPC safety for competitive advantage​.”

Research based on virulence and pathogenic characteristics

Dr. Ricke’s research program is primarily focused on virulence and pathogenic characteristics of foodborne Salmonella with emphasis on the growth, survival and pathogenesis of the organism under conditions encountered during food production and processing.

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

Dr. Ricke carried out three tests of RPCs as a platform for generating the bacteria biofilms of common pathogens.

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 bacteria not only attached to the RPC, but could not be dislodged by either sanitizers or physical scrubbing.

'We are committed to a culture of continuous improvement'

Welcome reiterated RPCs undergo a thorough cleaning and sanitation process after each use, and have never been associated with foodborne illness.

Because our industry takes food safety seriously, and because we are committed to a culture of continuous improvement, we monitor the complete body of research on container safety to ensure we will continue to provide our customers with safe products​,” he said.

Reusable plastic containers (RPCs) are a safe, efficient and sustainable method for transporting fresh food from farms and processing locations to retail markets​. 

Without a strong commitment to producing and maintaining safe products, nothing else we do is possible​.”

To eliminate contamination risk, Dr. Ricke recommends shippers and retailers choose single-use packaging.

Everyday, you can pick up a newspaper, turn on the television or read online about a new outbreak on a number of products involving US food supply​,” he added.

Our job as experts in food science is to determine how to avoid those risks, and from what we know through research is 1) reuse is a source for contamination; and 2) cleaning or scrubbing does not eliminate biofilms; so this will continue to confront us​.”

Related topics: Regulation and safety

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