Validation of Quaternary Ammonia and Hydrogen Peroxide Powder for Control of Listeria monocytogenes in Ready-to-Eat Meat and Poultry Plants

Introduction:   Listeria monocytogenes is a pathogenic microorganism that is endemic in plant processing environments. Some best practices that are being utilized by ready-to-eat (RTE) processors seem to be working based on environmental monitoring data. Many times, however, these processes are not validated and questions remain regarding their true effectiveness. 

Purpose:   The objective of this study was to assess the effectiveness of two chemical interventions, quaternary ammonia (quat) and hydrogen peroxide (H₂O₂) powder, to control Listeria monocytogenes in RTE meat and poultry processing facilities.

Methods:   To understand the effectiveness of dry, powdered quat and hydrogen peroxide against L. monocytogenes under commercial plant conditions; clean and soiled floor tiles at two moisture levels were tested. In addition, the effect of contamination level was investigated at two inoculation levels. A cold-adapted cocktail culture of seven strains of L. monocytogenes, including two quat-resistant strains was used for inoculation. A fully cooked turkey breast product was used to simulate RTE meat plant conditions.

Results:   The survival of L. monocytogenes on the floor tiles was influenced by the presence organic components. Quat was not effective against L. monocytogenes on clean or soiled dry surfaces. Quat was also influenced by moisture and required moisture to become effective against L. monocytogenes. The efficacy of H₂O₂ and quat increased as moisture levels increased. H₂O₂ was effective against L. monocytogenes on clean or soiled dry surfaces. The efficacy of H₂O₂ was more significant in the presence of moisture.

Significance:   Overall, H₂O₂ was more effective against L. monocytogenes under similar conditions compared to quat.