Ready-to-eat (RTE) products that undergo further handling after cooking (e.g. peeling or slicing) show the highest prevalence of Listeria monocytogenes (one to ten percent). Though rare, listeriosis is responsible for 28 percent of foodborne disease-related deaths. Therefore, the industry has adopted, among other methods, post-packaging pasteurization to control Listeria monocytogenes on product surfaces. However, in-package heat treatments may require up to eight minutes or more to achieve a 3-log10 reduction of Listeria monocytogenes, thus affecting product quality. This integrated pasteurization and packaging system offers a competitive alternative to existing hot water or steam-based in-package pasteurization equipment. It will be much less expensive, easier to install, and have a much smaller footprint. It will represent a food safety breakthrough for the American meat industry and beyond, as the technology could be extended to other food products. OBJECTIVES: This Small Business Innovation Research Phase 1 project proposes to investigate an innovative pasteurization technique combining pasteurization and packaging in a single unit to eliminate or reduce Listeria monocytogenes on the surface of ready-to-eat (RTE) meat and poultry products. APPROACH: USDA has invented a method to pasteurize the surface of hot dogs that alternates cycles of vacuum-steam-vacuum ('flash' or VSV pasteurization). USDA's process demonstrated a 3 to 5 log10 reduction of Listeria innocua in only 1 to 3 seconds. ALKAR-RapidPak intends to incorporate this new technology into cost-effective packaging equipment where VSV cycles will surface pasteurize the product, immediately followed by a vacuum-packing step. Such system will eradicate Listeria monocytogenes on the surface of ready-to-eat (RTE) products in a few seconds while preserving their sensory characteristics. PROGRESS: 2003/10 TO 2004/09 Surface pasteurization by applying steam or hot water prior to or after packaging of processed foods may be used to eliminate pathogens such as Listeria monocytogenes from ready-to-eat (RTE) meat and poultry products. The objective of this project was to evaluate the feasibility of integrating surface pasteurization into a RapidPak continuous vacuum packaging system to reduce L. monocytogenes from fully cooked franks at the very last possible step of food packaging before retails. In this research, surface pasteurization by steam that was applied into a continuous RapidPak vacuum-packaging machine achieved 3 log reductions for L. monocytogenes on fully cooked franks in 1.5 s. The integration of surface pasteurization into a commercial vacuum packaging system not only minimizes any negative effect of heat on food quality by substantially reducing treatment time from minutes to seconds, but also avoids any chance of pathogen recontaminations by immediately vacuum-sealing the top films of food packages after heat treatment. This innovation provides a commercially applicable means for effectively eradicating L. monocytogenes from RTE meat and poultry products at the very last possible step of food retail packaging before reaching consumers to ensure food safety. IMPACT: 2003/10 TO 2004/09 Recent incidences of foodborne illness outbreaks associated with L. monocytogenes have prompted governmental regulatory agencies to impose a final rule to control L. monocytogenes in RTE meat and poultry products. This innovation will enable real-time integration of surface pasteurization into their current production line-speed and help to reduce food-poisoning outbreaks and food product recalls that have cost hundreds of millions of dollars, hurt industry earnings, and forced many small and large U.S. firms out of business. PUBLICATIONS (not previously reported): 2003/10 TO 2004/09 1. Murphy, R.Y., R.E. Hanson, N.R. Johnson, L.L. Scott, N. Feze, and K. Chappa. 2004. Combining antimicrobial and steam treatments in a vacuum packaging system to control Listeria monocytogenes on ready-to-eat franks. Journal of Food Science. (accepted on Oct 25, 2004) 2. Murphy, R.Y., R.E. Hanson, N. Feze, N.R. Johnson, L.L. Scott, and L.K. Duncan. 2004. Eradicating L. monocytogenes from fully cooked franks using an integrated pasteurization/packaging system. Journal of Food Protection. (accepted on Oct. 29, 2004) 3. Murphy, R.Y., R.E. Hanson, L.K. Duncan, N. Feze, and B.G. Lyon. 2004. Consideration for post-lethality treatments to reduce Listeria monocytogenes from fully cooked bologna using ambient and pressurized steam. Food Microbiology. (accepted on September 17, 2004)
