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United States Department of Agriculture

Agricultural Research Service

Title: Effect of Gamma Or Beta Radiation on Salmonella Dt 104 Strains in Ground Pork

Authors
item Rajkowski, Kathleen
item Niebuhr, Steven - IOWA STATE UNIVERSITY
item Dickson, James - IOWA STATE UNIVERSITY

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 11, 2006
Publication Date: June 1, 2006
Citation: Rajkowski, K.T., Niebuhr, S.E., Dickson, J. 2006. EFFECT OF GAMMA OR BETA RADIATION ON SALMONELLA DT 104 STRAINS IN GROUND PORK. Journal of Food Protection. 69(6):1430-1433.

Interpretive Summary: Some strains of Salmonella are now resistant to multiple antibiotics used to treat human infections. The study used three different ground pork products: 90% lean, 50:50 fat/lean and 100% fat. In order to determine the irradiation dose required for a 90% inactivation of Salmonella DT 104 in these pork products a gamma and an electron beam irradiator were used. The fat content of the ground pork products did not affect in the dose required to inactivate 90% of the Salmonella DT 104 when using either the gamma or e-beam irradiator. There was a difference in inactivation dose required for 90% inactivation between the two irradiation sources, but this dose difference was within the reported range for irradiation destruction of Salmonella contaminated raw meat products. Low dose of irradiation, regardless of the source used, will inactivate Salmonella DT 104 and therefore, provide a safer raw meat product for the consumer.

Technical Abstract: Mixtures of six Salmonella Typhimurium DT 104 strains were inoculated into three ground pork products to determine the effect of fat content on the radiation resistance of Salmonella DT 104. The ground pork products were 90% lean, 50:50 fat:lean and 100% fat. In addition two different types of ionizing radiation were also compared, a gamma radiation source in a self contained 137Cesium irradiator and a 10 MeV accelerator producing electrons (e-beam). The D-10 values (dose required for a 90% inactivation of viable CFU) for Salmonella DT 104 inoculated into 90% lean ground pork, 50:50 fat/lean ground pork and 100% pork fat were 0.42 kGy, 0.43 kGy and 0.43 kGy, respectively. In contrast, the D-10 values for Salmonella DT 104 irradiated using the gamma source were 0.56, 0.62 and 0.62 kGy when suspended in 90% lean ground pork, 50:50 fat/lean ground pork and 100% pork fat, respectively. There was no statistical significant difference in D-10 values for the three products for the individual process, therefore fat content had no effect. There was a significant difference (P = 0.001) between the D-10 values obtained between the two irradiation sources. The results of this study do show that these D-10 values are within the reported range for irradiation destruction of Salmonella contaminated raw meat products.

Last Modified: 12/18/2014