Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2005
Publication Date: 7/1/2006
Citation: Leverentz, B., Conway, W.S., Janisiewicz, W.J., Kurtzman, C.P., Abadias, M., Camp, M.J. 2006. Biocontrol of foodborne pathogens on fresh-cut apples using naturally occurring bacterial and yeast antagonists. Applied and Environmental Microbiology. 72:1135-1140. Interpretive Summary: The fresh-cut produce industry is a rapidly growing $10 to $12 billion a year industry, accounting for over 10% of all produce sales in the U.S., and has annual growth rates in the double digits. Along with the rapid development of this industry, however, new problems have arisen in the food safety area. Various sanitizers, which are effective in reducing foodborne pathogen populations on whole produce, are not as effective on fresh-cut produce. Also, the extensive use of these sanitizers has resulted in various foodborne pathogens developing resistance to them. Naturally occurring bacteria and yeasts may be viable alternatives to these sanitizers. We have shown that one bacterium and three yeasts proved effective in preventing the growth or survival of the foodborne pathogens Listeria monocytogenes and Salmanella Poona on fresh-cut apple tissue. The fresh-cut produce industry can use these microorganisms to implement a successful biocontrol strategy to reduce the potential outbreaks of foodborne diseases. This will benefit not just the fresh-cut processors, but retail outlets, foodservice organizations and consumers by providing a high quality and safe food supply.
Technical Abstract: Fresh-cut apples contaminated with either L. monocytogenes or S. poona, both foodborne pathogen strains from outbreaks on produce, were treated with one of seventeen antagonists originally selected for their ability to inhibit fungal postharvest decays on fruit. While most of the antagonists increased the growth of the foodborne pathogens, four of them, including Gluconobacter asaii (T1-D1), a Candida spp. (T4-E4), Discosphaerina fagi (ST1-C9), and Metchnikowia pulcherrima (T1-E2) proved effective in preventing the growth or survival of foodborne human pathogens on fresh-cut apple tissue. The contaminated apple tissue plugs were stored for up to seven days at two different temperatures. The four antagonists survived or grew on the apple tissue at 10 or 25°C. These four antagonists reduced the L. monocytogenes populations and except for the Candida spp. (T4-E4), also reduced S. poona populations. The reduction was higher at 25°C than at 10°C, and the growth of the antagonists, as well as pathogens, increased at the higher temperature.