Control of listeria monocytogenes in recycled chill brine using ultraviolet light and antimicrobial agents

Postprocessing contamination of the products in a processing plant has been identified as one of the major reasons for food contamination with Listeria; brining is one such postprocessing area. Our previous study has shown that the combinations of UV and antimicrobials reduces the number of this organism significantly in fresh brine, but brine is usually recycled from days to weeks depending on its use. Therefore, this study is focused on the reduction of L.monocytogenes in recycled chill brine (obtained from a frankfurter processor) using the combinations of UV and antimicrobial agents, such as citric acid (CA), hydrogen peroxide (HP) and dimethyl dicarbonate (DMDC). Results show that the combinations of UV and 2000ppm and 4000ppm HP were the most effective treatments in reducing the Listeria population with the total processing time of 120min. Both of these treatments were found to be more effective than UV or HP alone. Additionally, all other treatments, such as the combinations of UV and CA (0.2 and 0.5%) and UV and DMDC (250 and 500ppm) were comparatively less effective. This may be due to the presence of organic matter in spent brine, which may have reduced the penetration of UV and availability of antimicrobials for microbial interaction. PRACTICAL APPLICATIONS: The brine solutions are generally recycled in industries for up to 4 weeks as per United States Department of Agriculture (USDA) guide. Thus, it is very important to study various treatments to process recycled brine that was used to process ready-to-eat (RTE) meat products to prevent foodborne diseases or outbreaks. The use of UV light and antimicrobial agents to control L.monocytogenes in recycled brines to product cooling in the RTE meat industry is described. The study provides information on exposure time to UV light and level of antimicrobial agent that result in inactivation of the pathogen. Industry may benefit from our research in their validation efforts to control L.monocytogenes for recycled brine in recirculating chill brine systems through the use of UV light and antimicrobial agents.