食品加工および技術ジャーナル

概要

Inactivation of Listeria innocua on Frankfurters by Flash Pasteurization and Lauric Arginate Ester

Christopher Sommers, William Mackay, David Geveke, Bryan Lemmenes and Seth Pulsfus

Listeria monocytogenes , a psychrotrophic food-borne pathogen, is a recurring post-process contaminant on ready-to-eat meat (RTE) products including frankfurters. Flash Pasteurization (FP) uses short pulses of steam to decontaminate the surface of precooked sausages such as frankfurters. The antimicrobial lauric-arginate-ester (LAE) has been shown to reduce levels of L. monocytogenes and its nonpathogenic surrogate L. innocua on frankfurters. In this study the use of FP to inactivate L. innocua on frankfurters followed by application of LAE immediately prior to vacuum-packaging in a pilot plant setting was investigated. Use of FP (1.5 s, 120°C steam), LAE (3.33 ml of a 5% volume/volume solution per pack of four frankfurters), or FP followed by application of LAE, resulted in a 2.5, 1.6, and 3.3 of log reductions of L. innocua that was surface-inoculated onto frankfurters, respectively. Although FP alone reduced L. innocua levels by 2.5 log, the bacterium recovered and grew to a density of >10 6 CFU/g within 2 weeks during refrigerated storage (10°C). LAE inhibited L. innocua growth for 8 weeks, but the bacterium was able to recover and grow to a density of >10 6 CFU/g by week 12. The use of FP in combination with LAE effectively inhibited the growth of L. innocua for 12 weeks. The use of FP in combination with LAE had little effect on frankfurter color and texture, and was found to be an effective hurdle process for decontamination of frankfurter surfaces.