ARS | Publication request: Application of ultrasonic technology for killing Salmonella and Listeria monocytogenes in fluid system

Submitted to: Institute of Food Technology
Publication Type: Abstract Only
Publication Acceptance Date: June 6, 2009
Publication Date: June 6, 2009
Citation: Murphy, R., Beard, B., Macry, J., Berrang, M.E. 2009. Application of ultrasonic technology for killing Salmonella and Listeria monocytogenes in fluid system. Institute of Food Technology. June 6-9,2009. Anaheim, CA. 236-01.

Technical Abstract: Emerging technologies are being investigated or implemented by U.S. food processors to help remove illness-causing pathogens from our food supplies. Many emerging food processing technologies are not new, but rather are innovative or expanded applications of existing technologies that had been examined, developed, or used for other purposes. In response to increased food safety concerns and heightened awareness of potential pathogen reduction abilities, recent advancements in various emerging technologies have made them more commercially feasible in treating food. Ultrasound is a non-thermal non-chemical physical processing technique available in a broad range of systems. Applications can provide opportunities for increases in process efficiency through enhanced yields, increased throughput and reduced cost processing. High-power ultrasonic technology is currently used for cell disruption, particle size reduction, welding, and vaporization and has been shown to be effective in killing bacterial spores. In this study, ultrasonic technology was combined with ozonation in a continuous flow system to treat saline solution containing 6 to 7 log10 CFU/mL of Salmonella. The inoculum included a cocktail of S. Montevideo, S. Senftenberg, S. Gaminara, S. Heidelberg, S. Anatum, and S. Typhimurium that was isolated from juice, poultry, and food processing environment. The inoculated saline solution was treated in a system with 300 gallon capapcity and a flow rate of 50 gallons/min. Within about 30 to 60 min, no survival of Salmonella was detected. A cocktail of six Listeria monocytogenes isolates that were originally recovered from meat product and processing environment was also used in this study. Saline was inoculated with 7 log10 CFU Listeria monocytogenes per mL. The time required to completely kill L. monocytogenes was about 300 min. This research shows that a combination of ozonation and ultrasonication can provide benefits for reducing pathogens in liquid solutions such as brine or chill water to improving food safety.