Food Safety Magazine, August/September 2008

effective at reducing enteric pathogen contamination on fruits and vegetables; however, with several types of produce, product softening due to changes in

duce items. Such treatment conditions may require multiple hurdle steps that have
synergistic antimicrobial activities. As an example, irradiation dosages required for
pathogen inactivation are lower if packages contain a modified atmosphere or if an
antimicrobial coating is applied to the produce item prior to irradiation. Keep in
mind that most chemical and biological
treatments are only effective on surface
contamination; hence, combination or
sequential treatments involving a physi-
cal intervention may be needed if
pathogens are internalized. Developing
multiple-hurdle or sequential interven-
tion treatments will likely be the most
effective approach to minimizing the
transmission of enteric pathogens
through fresh-cut produce.

“Pathogen contamination of

produce growing in fields may

be reduced by applying

good agricultural practices.”

pectic substances occurs with a dose of 1 kGy which is needed to kill some pathogens. Such results illustrate the challenge of attempting to find one intervention that would be equally effective for all types of produce. Hence, in the absence of having a cross-cutting intervention, we are challenged with developing food safety interventions that can not only effectively inactivate pathogens, but are also mild enough to not adversely affect the sensory qualities of fragile fresh pro-

References

1. Takeuchi, K. and J.F. Frank. 2000. Penetration of Escherichia coli O157:H7 into lettuce tissues as affected by inoculum size and temperature and the effect of chlorine treatment on cell viability. J. Food Prot. 63:434-440.

2. Li, Y., R.E. Brackett, J. Chen, and L.R. Beuchat. 2001. Survival and growth of Escherichia coli O157:H7 inoculated onto cut lettuce before or after heating in chlorinated water, followed by storage at 5° or 15°C. J. Food Prot. 64:305-309.

3. Delaquis, P., S. Stewart, S. Cazaux, and P. Toivonen. 2002. Survival and growth of Listeria monocytogenes and Escherichia coli O157:H7 in ready-to-eat lettuce washed in warm chlorinated water. J. Food Prot. 65:459-464.

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Michael Doyle is a Regents Professor of Food Microbiology and Director of the Center for Food Safety at the University of Georgia. He is an active researcher in the area of foodborne bacterial pathogens and works closely with the food industry on issues related to the microbiological safety of foods. Dr. Doyle is a graduate of the University of Wisconsin-Madison where he received his B.S. degree in Bacteriology, and M.S. and Ph.D. degrees in Food Microbiology. He can be reached at mdoyle@uga.edu.

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Marilyn Erickson is an Associate Professor of Food Biochemistry within the Center for Food Safety and the Department of Food Science and Technology at the University of Georgia. She is a graduate of North Carolina State University and Oregon State University where she received her B.S. and M.S./Ph.D. degrees, respectively. Her current research interests are centered on factors affecting preharvest contamination of leafy greens and the inactivation of pathogens in animal manure-based composts. She can be reached at mericks@uga.edu.