Combining Pediocin with Postpackaging Irradiation for Control of Listeria monocytogenes on Frankfurters

Abstract

Frankfurters, in 1-link, 5-link, or 10-link packages, were surface inoculated with a five-strain mixture of Listeria monocytogenes (3.40 or 5.20 log CFU/g) after treatment with 3,000 arbitrary units (AU) or 6,000 AU of pediocin (in ALTA 2341) per link. The frankfurters were vacuum packaged, after which the 1-link and 5-link packages were irradiated at 1.2 or 2.3 kGy and the 10-link packages were irradiated at 1.4 or 3.5 kGy. L. monocytogenes was enumerated following the treatments. Selected treatments were subsequently evaluated during storage at 4, 10, and 25°C for up to 12 weeks. Combination of pediocin with postpackaging irradiation at 1.2 kGy or more was necessary to achieve a 50% reduction of L. monocytogenes on frankfurters in 1-link or 5-link packages. The combination of 6,000 AU of pediocin and irradiation at 2.3 kGy or more was effective in all package sizes for inhibition of the pathogen for 12 weeks at 4 or 10°C. There was a synergistic effect between pediocin and irradiation for inhibition of L. monocytogenes. Storage at 4°C enhanced the antilisterial effects of the treatment combinations, with little or no growth of the pathogen in 1-link or 5-link packages during 12 weeks of storage. In general, these treatments did not affect the sensory quality of frankfurters.