Antimicrobial films and coatings for inactivation of Listeria innocua on ready-to-eat deli turkey meat

Abstract

Edible antimicrobial coating solutions incorporating chitosan, lauric arginate ester (LAE) and nisin were developed to reduce foodborne pathogen contamination on ready-to-eat (RTE) meats. RTE deli meat samples were directly coated with the solutions, or treated with solution-coated polylactic acid (PLA) films. The antimicrobial efficacy of the coatings and films against Listeria innocua inoculated onto the surface of RTE meat samples was investigated. Antimicrobial coatings with 1.94 mg/cm2 of chitosan and 0.388 mg/cm2 of LAE reduced L. innocua by ca. 4.5 log CFU/cm2. Nisin (486 IU/cm2) showed less effectiveness than LAE (0.388 mg/cm2) and addition of nisin to the antimicrobial coatings or films containing LAE (0.388 mg/cm2) did not enhance the total antimicrobial effectiveness. Combining antimicrobial coatings or films with flash pasteurization (FP), which uses short burst of steam under pressure, further reduced L. innocua, achieving over a 5 log reduction. There was no significant difference in the effectiveness of antimicrobial films versus the coatings (p > 0.05). These data show the potential use of antimicrobial packaging alone, or in combination with FP, in preventing foodborne illness due to post-processing contamination of RTE meat products.