There is growing concern that the free radical scavenging effect of antioxidants added to meats might reduce the antimicrobial effectiveness of ionizing radiation. A study was conducted to determine the effect of vitamin E on the behavior (growth) of Listeria monocytogenes and color stability in turkey meat following electron beam irradiation. Raw ground turkey breast meat from birds fed diets containing 0 (control), 50, 100, and 200 IU/kg of vitamin E was inoculated with a five-strain mixture of L. monocytogenes to give approximately 107 CFU/g. Inoculated samples were irradiated at 0, 0.5, 1, and 2 kGy and stored aerobically (12 days) or under vacuum (42 days) at 4°C. L. monocytogenes survivors were determined by plating samples on modified Oxford medium and counting colonies on modified Oxford medium plates after 48 h at 35°C. Meat color was measured using a colorimeter. Irradiation at 2.0 kGy resulted in an approximately 3.5-log reduction of initial numbers of L. monocytogenes. There were no significant differences in D-values (decimal reduction times) for L. monocytogenes in meat irrespective of vitamin E treatment (P > 0.05). Also, vitamin E treatments did not affect growth of the pathogen in aerobic or vacuum-packaged samples following irradiation (P > 0.05). Compared with controls, irradiated meat from birds fed 100 or 200 IU/kg of vitamin E demonstrated significant improvement in color stability (lightness and redness values) during aerobic storage (P < 0.05). Dietary vitamin E (100 to 200 IU/kg) has good potential for improving the color stability of turkey meat without compromising the microbial safety of the irradiated product.

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