ARS | Publication request: Radiation inactivation of foodborne pathogens on frozen seafood products

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 18, 2010
Publication Date: April 1, 2011
Citation: Sommers, C.H., Rajkowski, K.T. 2011. Radiation inactivation of foodborne pathogens on frozen seafood products. Journal of Food Protection. 74(4):641-644.

Interpretive Summary: Food-borne illness due to consumption of contaminated seafood is a problem in the United States. Ionizing (gamma) irradiation is a safe and effective technology for improving the safety of many types of food. In this study we examined the use of gamma radiation to inactivate Salmonella, Listeria, and Staphylococcus aureus in frozen (-20 degrees C) seafood. The D-10 (the radiation dose needed to inactivate 90% of microorganism) for Listeria monocytogenes, Staphylococcus aureus, and Salmonella spp. inoculated onto seafood were significantly less than the radiation dose needed to inactivate these food-borne pathogens in frozen meat, poultry, and vegetables. This work will assist the U.S. FDA to evaluate a petition to allow irradiation of seafood in the United States and provides valuable information to the seafood and radiation processing industry.

Technical Abstract: Food-borne illness due to consumption of contaminated seafood is, unfortunately, a regular occurrence in the United States. Ionizing (gamma) irradiation can effectively inactivate microorganisms and extend the shelf-life of seafood. In this study, the ability of gamma irradiation to inactivate food-borne pathogens in frozen seafood (scallops, lobster meat, blue crab, swordfish, octopus, and squid) was investigated. The D-10 (the radiation dose needed to inactivate 1 log of microorganism) for Listeria monocytogenes, Staphylococcus aureus, and Salmonella spp. inoculated onto frozen seafood (-20 degrees C) were 0.43-0.66, 0.48-0.71, and 0.47-0.70 kGy, respectively. In contrast, the D-10 for the same pathogens suspended in frozen pork was 1.26, 0.98, and 1.18 kGy for L. monocytogenes, S. aureus, and Salmonella spp., respectively. The radiation dose (D-10) needed to inactivate these foodborne pathogens on frozen seafood is significantly lower than for frozen meat or frozen vegetables.