Use of Pediocin with Other Barriers for Control of L.m. in RTE Processed Meats

Pediocin, a natural antimicrobial, was evaluated as a topical treatment for finished ready-to-eat products to determine if it will retard Listeria monocytogenes growth. The results indicated that the pediocin significantly reduced the number of Lm on packaged frankfurters and delayed growth of the remaining cells during storage.

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Objectives

To study effectiveness of pediocin AcH for control of Listeria monocytogenes (Lm); to determine effectiveness of combined barriers such as pediocin with postpackaging thermal treatments, and pediocin with post-packaging irradiation treatments; and to evaluate delivery systems for pediocin including product spraying, coextrusion processing and interior coatings for casings.

Conclusions

Results of this study showed that pediocin activity of the commercially available Alta 2341® significantly reduced the number of Lm on packaged frankfurters and delayed growth of the remaining cells during storage. The extent of the time delay was highly temperature dependent. Post-packaging pasteurization by either thermal treatment or irradiation was very effective. Thermal treatment effectiveness was dependent on the package arrangement, temperature and time. Packages with frankfurter-to- frankfurter contact protected Lm cells from the heat process. Temperature of pasteurization had greater impact than time on surviving Lm in this study. No interaction or synergism occurred between pediocin treatments and thermal pasteurization. Irradiation, on the other hand, not only had a large impact on Lm, but also was synergistic with the pediocin treatments to affect Lm to an even greater extent when used in combination with pediocin. Most of the quality characteristics of the frankfurters measured in this study were unaffected by the antilisterial treatments. The exceptions included color changes in lightness and redness. Products with pediocin and pasteurization treatments were darker and redder but the differences relative to controls were small. Sensory panel scores for texture resulted in a higher firmness score for the thermally-pasteurized frankfurters but this was not confirmed by the instrumental texture measurements. Use of pediocin-treated casings or co-extrusion technology offers easy means to deliver bacteriocins or other compounds to the surface of frankfurters but further work is needed to improve antimicrobial effectiveness when these systems are used.

Deliverable

This study identifies three effective Listeria interventions for frankfurters: pediocin; thermal post-packaging pasteurization; and irradiation. Pediocin and irradiation seem to have a synergistic effect while pediocin and thermal pasteurization do not. A potential delivery mechanism was identified.