Fluctuating temperatures increase bagged salad risk

02/13/2014 06:05:00 PM
Tom Karst

A new study shows that fluctuating temperatures during transportation, in the back room at the store and on the shelves leads to pathogen growth and diminishes the quality of salads.

The study, published in the February Journal of Food Protection, looked at the growth of E. coli O157:H7 and Listeria monocytogenes in packaged fresh-cut romaine mix at fluctuating temperatures during commercial transport, retail storage and display.

Over a 16-month period, a series of time-temperature profiles for bagged salads were obtained from five transportation routes covering four geographic regions, as well as during retail storage and display, according to the study.

Five time-temperature profiles were collected during two to three days of transport, one and three days of retail storage, and three days of retail display. Pathogens in the samples were then duplicated in a programmable incubator to assess E. coli O157:H7 and L. monocytogenes growth in commercial bags of romaine lettuce mix, according to the abstract.

“Based on the simulation, both pathogens generally increased during transport, storage and display,” the authors said. “However, retail storage duration can significantly impact pathogen growth.”

Researchers said they believe the data gathered will be useful in measuring food safety risk.

“This large-scale U.S. study — the first using commercial time-temperature profiles to assess the microbial risk of leafy greens — should be useful in filling some of the data gaps in current risk assessments for leafy greens,” the authors said in the abstract.

Study results can be found online



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LGMA    
Sacramento  |  February, 19, 2014 at 10:50 AM

Health experts emphasize that food safety is a shared responsibility that starts on the farm, but is important all along the supply chain. For fresh produce, particularly leafy greens which are often eaten in an uncooked state, proper food safety practices are critical to reducing foodborne illness. The California Leafy Greens Marketing Agreement is devoted to ensuring a set of science-based food safety practices are being following on leafy greens farms. But LGMA members lose the ability to protect consumers when the leafy greens they carefully produce leave their coolers in California and head to dinner tables around the world. We appreciate the work these scientists have done. Only through research can we hope to reduce the number of foodborne illnesses associated with leafy greens both in the field and during post-production handling. It’s clear the findings from this study can fill vital data gaps that will help retailers and transportation companies develop proper handling procedures that can prevent illness. Research like this can help everyone who shares in the distribution of produce to provide consumers and their families the safest food possible.

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