Control of Listeria monocytogenes on Alternatively Cured Ready-to-Eat Ham Using Natural Antimicrobial Ingredients in Combination with Post- Lethality Interventions

Abstract

Ready-to-Eat (RTE) meat and poultry products manufactured with natural or organic methods may be at greater risk for Listeria monocytogenes growth, if contaminated, than their conventional counterparts due to the required absence of preservatives and antimicrobials. Thus, the objective of this study was to investigate the use of commercially available natural antimicrobials in combination with post-lethality interventions for the control of L. monocytogenes growth and recovery on alternatively-cured RTE ham. Antimicrobials evaluated were cranberry powder (90 MX), vinegar (DV), and vinegar and lemon juice concentrate (LV1 X). Post-lethality interventions studied included high hydrostatic pressure at 400 MPa (HHP), lauricarginate (LAE), octanoic acid (OA), and post-packaging thermal treatment (PPTT). Viable L. monocytogenes on modified Oxford (MOX) and thin agar layer (TAL) media were monitored through 98 days of product storage at 4 ± 1°C. The post-lethality treatments of HHP, OA, and LAE significantly reduced initial viable L. monocytogenes numbers compared to the control, regardless of the antimicrobial ingredient used in the formulation while PPTT did not. Only when used in combination with DV and LV1 X did HHP, OA, and LAE exhibit sustained suppression, of L. monocytogenes recovery and growth throughout refrigerated storage. As a result, the use of natural antimicrobial ingredients such as DV and LV1 X in combination with post-lethality interventions such as HHP, LAE, and OA represents an effective multi-hurdle approach that could be instituted by manufacturers of organic and natural processed meat and poultry products for L. monocytogenes control.