Control of Listeria monocytogenes on cooked cured ham by formulation with a lactate-diacetate blend and surface treatment with lauric arginate

Abstract

Ready-to-eat (RTE) meat products have been identified as a significant source of listeriosis in humans in the United States. Meat processors in the United States are required to use one of three alternatives to control L. monocytogenes in RTE meats: (i) a postlethality inactivation treatment along with a L. monocytogenes growth inhibitor; (ii) a postlethality inactivation treatment or a growth inhibitor; or (iii) sanitation measures and intensive testing. Lauric arginate (LAE) has been proposed as an effective postlethality inactivation treatment. The present study was conducted to investigate the antimicrobial effect of a lactate-diacetate blend in the formulation combined with surface application of LAE on cooked cured ham inoculated with L. monocytogenes, vacuum packaged, and stored at 4°C for up to 90 days. The treatments evaluated were (i) control ham with no added antimicrobials (control); (ii) ham formulated with 1.68% potassium lactate and 0.12% sodium diacetate (PLSD); (iii) control ham with 0.07% LAE as a surface treatment (LAE); and (iv) ham formulated with PLSD and LAE surface treatment (sprayed in bag and distributed across meat surface during vacuum packing) (PLSD + LAE). Use of only LAE as a surface treatment resulted in an initial 1-log CFU/g reduction in levels of L. monocytogenes on ham; however, this reduction only delayed the growth of the pathogen to 8 log CFU/g by 12 days when compared with the control ham without added antimicrobials. Use of PLSD in the formulation of ham resulted in a complete inhibition of L. monocytogenes throughout storage. The combination of PLSD in the formulation and a surface treatment with LAE resulted in an initial 0.7-log CFU/g reduction of the pathogen on ham and complete inhibition of the pathogen at the reduced level throughout storage. Formulation of ham with a lactate-diacetate blend combined with lauric arginate as a surface treatment will allow RTE meat processors to effectively achieve alternative 1 status, as designated by the U.S. Department of Agriculture Food Safety and Inspection Service, in their facilities. Copyright ©, International Association for Food Protection.