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United States Department of Agriculture

Agricultural Research Service

Title: Effectiveness of Irradiation Treatments in Killing Listeria Monocytogenes on Fresh Vegetables at Refrigerated Temperature

Authors
item Bari, M - NATIONAL FOOD RESEARCH
item Nakauma, T - NATIONAL FOOD RESEARCH
item Todoriki, S - NATIONAL FOOD RESEARCH
item Juneja, Vijay
item Isshiki, K - NATIONAL FOOD RESEARCH
item Kawamoto, S - NATIONAL FOOD RESEARCH

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 15, 2004
Publication Date: N/A

Interpretive Summary: Listeria monocytogenes is a pathogen of major concern for the food industry because of its association with several outbreaks of foodborne illness. One of the common and effective means of controlling this bacterium is the use of ionizing radiation. We found that the treatment of brocolli, mung bean sprouts, cabbage and tomatoes with 1 kGy irradiation dose could completely kill the indigenous microflora and eliminate 99.999% of Listeria, thereby extending shelf-life of the produce at refrigerated temperatures. This information will be of immediate use to consumers and to the food industry and regulatory agencies to aid in the development of guidelines to ensure safety of the food supply.

Technical Abstract: The application of ionizing radiation has been demonstrated to be effective in controlling the growth of food spoilage and foodborne pathogenic bacteria. Therefore, this study was done to investigate the effectiveness of irradiation treatment to eliminate Listeria monocytogenes on laboratory-inoculated broccoli, cabbage, tomatoes and mung bean sprouts. Treatment of broccoli and mung bean sprouts at 1.0 kGy irradiation dose resulted in reductions of approximately 4.88 and 4.57-log10 CFU/g, respectively, of a five strain cocktail of Listeria monocytogenes. Reductions of approximately 5.25 and 4.14-log10 CFU/g were found with cabbage and tomato, respectively at a similar dose level. The appearance, color, texture, taste and overall acceptability, did not undergo significant changes by 7 days of post irradiation storage at 4 C, in comparison to control samples. Therefore, low-dose ionizing radiation treatment could be an effective method for eliminating L. monocytogenes on fresh and fresh-cut produce.

Last Modified: 11/23/2014