title: Control of Listeria monocytogenes on cold-smoked salmon using chitosan-based antimicrobial coatings and films.
abstract: The relatively high incidence of Listeria monocytogenes in ready-to-eat (RTE) products such as cold-smoked salmon is of serious concern. The objective of this study was to evaluate the efficacy of chitosan-based edible coatings and films incorporating 3 generally recognized as safe (GRAS) antimicrobials, sodium lactate (SL), sodium diacetate (SD), and potassium sorbate (PS), against L. monocytogenes on cold-smoked salmon. Salmon samples were surface-inoculated with a 5-strain cocktail of Listeria monocytogenes to a final concentration of 4.4 log CFU/cm(2) and then either coated with chitosan solutions or wrapped with chitosan films with or without the 3 antimicrobials. The samples were then vacuum packaged and stored at 4 °C for 30 d. The chitosan coatings with or without the antimicrobials consistently showed higher efficacy against L. monocytogenes than chitosan films having the same compositions. The most effective film treatments, chitosan films containing 1.2% SL/0.25% SD or 2.4% SL, achieved ≥ 1.3 log reductions of L. monocytogenes during the 30 d of refrigerated storage, while the most effective coating treatments, chitosan coatings containing 1.2% SL/0.25% SD or 0.15% PS/0.125% SD, achieved ≥ 2.8 log reductions. Practical Application: This study shows that chitosan-based edible coatings and films hold promise and can potentially assist fishery industries in their efforts to control L. monocytogenes.
authors.affiliation: Dept. of Animal & Food Sciences, Univ. of Delaware, Newark, DE 19716-2150, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Jiang
authors.forename: Hudaa
authors.initials: H
authors.lastname: Neetoo
authors.forename: Haiqiang
authors.initials: H
authors.lastname: Chen
mesh_terms: D000085:Acetates / Q000494:pharmacology; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D048271:Chitosan / Q000737:chemistry; D015169:Colony Count, Microbial; D057140:Fast Foods / Q000382:microbiology; D005503:Food Additives / Q000494:pharmacology*; D018857:Food Packaging; D005519:Food Preservation / Q000379:methods*; D005517:Foodborne Diseases / Q000517:prevention & control; D008089:Listeria monocytogenes / Q000187:drug effects*; D012034:Refrigeration; D012474:Salmon; D017747:Seafood / Q000382:microbiology*; D019354:Sodium Lactate / Q000494:pharmacology; D013011:Sorbic Acid / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000085:Acetates; D000890:Anti-Infective Agents; D005503:Food Additives; C548838:sodium diacetate; D048271:Chitosan; D019354:Sodium Lactate; D013011:Sorbic Acid