Risk of salmonella, norovirus and cyclospora transfer
GUELPH, ON, Oct. 10, 2013 /CNW/ - A new study indicates that Reusable Plastic Containers (RPCs) used to ship fruit and vegetables in Canada pose a risk for contamination.
The report, developed by a University of Guelph researcher, calls the possibility for contamination a significant concern. "The main outcome of the study is that the RPCs meant to be delivered in a sanitary condition were not effectively cleaned. From a food safety perspective this could mean that pathogens such as salmonella, norovirus and cyclospora could be transferred to produce," explains Keith Warriner, author of the study.
Warriner, who is the Food Safety and Quality Assurance Program Director at the University of Guelph adds that, "in addition to human pathogens, it is also possible that plant pathogens such as Erwinia, Pseudomonas, Xanthomonas and Ascomycetes could be transferred, thereby resulting in premature spoilage of produce."
In Canada some retailers demand farmers ship fruit and vegetables, from the farm to the store, using RPCs. The containers are rented by farmers to ship their produce and then returned to the United States for cleaning. In Ontario, for example, RPCs are shipped to Chicago for sanitization.
Containers at Ontario and Quebec farms were tested for overall sanitary status (visual inspection and ATP testing), in addition to bacterial counts (total aerobic counts) that included potential fecal indicators (enterobacteriaceae and coliforms). Collectively, 64% of all RPCs failed in terms of sanitary standards and 56% of trays had a higher aerobic count than expected on a cleaned surface. Trays were sampled as delivered thereby ruling out contamination at the farm.
"The results provided evidence to make a case of potential hazards," said Warriner. "RPCs used to ship food are a recipe for disaster. We recommend that the decontamination method for RPCs be reviewed to prevent carriage and transfer of human pathogens."
The results also show a significant variation in the sanitary status of RPCs, and that many RPCs were damaged and visibly dirty. Visual inspection of RPCs revealed a proportion that were damaged or had labels affixed from previous use. While the root of this problem is unknown, inefficient cleaning systems and travel to-and-fro wash stations in the USA may explain the sanitary issues.
The study was commissioned following food safety concerns expressed by the growers who are told to ship fruit and vegetables using RPCs, rather than the traditional choice, corrugated boxes.
"We have heard anecdotal reports from growers that the RPCs delivered to their farms sometimes arrive dirty," said André Plante, General Manager, Quebec Produce Growers Association. "For the safety of Canadians, we need to ensure all food in Canada is shipped using clean packaging, regardless of whether it is paper or plastic."
Commenting on the use of RPCs over corrugated by some packers and retailers, Mike Harwood, president and CEO of the World Containerboard Organization said he "believes produce retailers like to showcase their fruits and vegetables in corrugated packaging because boxes are a natural product, made from renewable wood fibre and are totally sustainable in our environment. Terrific retailers like Whole Foods, Publix, and Costco, just to name a few, realize that beautifully printed corrugated boxes also help them to sell more fresh produce to their customers."
About the Study
Keith Warriner, Professor of Food Safety at the University of Guelph, assessed the microbiological standard of reusable plastic containers used in different fresh produce packing stations. Locations in Ontario and Quebec were visited during the course of the study. At each location ten randomly selected RPCs were sampled.
A combination of ATP (adenosine triphosphate) swabs and microbiological analysis were chosen to determine the sanitary status of RPCs. ATP (adenosine triphosphate) readings taken at farms provided an estimate of viable cells present on the surface of RPCs. The standards set were those expected of a cleaned surface of a food contact surface within the food industry with a 20% failure rate being deemed the upper limit of acceptability. Trays were sampled as delivered thereby ruling out contamination at the packing facility.
SOURCE: Canadian Corrugated Containerboard Association
For further information: