Short-term bactericidal efficacy of lauric arginate against Listeria monocytogenes present on the surface of frankfurters

The antimicrobial lauric arginate (LAE) alone or in combination with an antimicrobial liquid smoke extract was studied as a postlethality treatment against Listeria monocytogenes on vacuum-packaged frankfurters. Treatment with 2 ml of 5,000 ppm of LAE reduced L. monocytogenes from 7.13 to 5.82 log CFU per package on day 0, and treatment with 3 ml reduced populations from 7.22 to 5.79 log CFU per package on day 0. Treatment with LAE and smoke flavor did not result in significantly different populations of L. monocytogenes (P < 0.05) compared with LAE alone. Log reductions on frankfurters 48 h after treatment with 3 to 4.5 ml of 5000 ppm of LAE ranged from 1.80 to 2.22, but these values were not significantly different between treatment volumes. Populations on dip-inoculated frankfurters 1 h after spraying with 2.5 ml of water (control) were 7.69 log CFU per package, and frankfurters treated with 2.5 ml of 5000 or 8000 ppm of LAE had populations of 6.03 and 5.85 log CFU per package, respectively. On spot-inoculated frankfurters, spray treatment with 2.5 ml of water resulted in L. monocytogenes counts of 8.16 log CFU per package after 1 h, whereas spray treatment with LAE at 5000 and 8000 ppm reduced counts within 1 h to 6.80 and 6.13 log CFU per package, respectively. All treatments resulted in reductions of > or = 1.68 log CFU per package, and many of the treatments caused a > 2-log reduction within 48 h. In this study, the shortterm efficacy of LAE against L. monocytogenes on vacuum-packaged frankfurters was demonstrated, providing support for use of this postlethality treatment on frankfurters and sausages for control of this pathogen.