Control of Listeria monocytogenes on ham steaks by antimicrobials incorporated into chitosan-coated plastic films.
Contamination of ready-to-eat (RTE) meat products such as ham steaks with Listeria monocytogenes has been a concern for the meat processing industry. The objective of this study was to evaluate the antilisterial efficacy of chitosan-coated plastic films alone or incorporating five generally recognized as safe (GRAS) antimicrobials. Effect of chitosan-coated plastic film on the growth of L. monocytogenes was first investigated in an aqueous system of culture medium broth and chitosan-coated films were able to inhibit the growth of L. monocytogenes in a concentration-dependent manner. However, chitosan-coated plastic films were not able to control the growth of L. monocytogenes on ham steaks. Therefore, five GRAS antimicrobials were subsequently incorporated into chitosan-coated plastic films to enhance their antilisterial effectiveness. Ham steaks were surface-inoculated with a five-strain cocktail of L. monocytogenes and then packaged in chitosan-coated plastic films containing 500 IU/cm(2) of nisin, 0.01 g/cm(2) of sodium lactate (SL), 0.0025 g/cm(2) of sodium diacetate, 0.003 g/cm(2) of potassium sorbate (PB), or 0.001 g/cm(2) of sodium benzoate (SB). The samples were stored at room temperature (ca. 20 degrees C) for 10 days. Incorporating antimicrobials into chitosan-coated plastic films slowed down or inhibited the growth of L. monocytogenes. The chitosan-coated plastic film containing SL was the most effective antimicrobial film and its efficacy against L. monocytogenes on ham steaks was evaluated during 12-week storage at 4 degrees C. The film showed excellent long-term antilisterial effect with the counts of L. monocytogenes being slightly lower than the initial inoculum. Chitosan-coated plastic films containing 0.001 g/cm(2) of SL have a potential to be used on ham steaks to control L. monocytogenes.
Ye
Mu
M
Department of Animal & Food Sciences, University of Delaware, Newark, DE 19716-2150, USA.
Neetoo
Hudaa
H
Chen
Haiqiang
H
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms; D048271:Chitosan / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D018857:Food Packaging / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D005520:Food Preservatives / Q000494:pharmacology; D006801:Humans; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development*; D008461:Meat Products / Q000382:microbiology*; D019346:Sodium Acetate / Q000494:pharmacology; D019354:Sodium Lactate / Q000494:pharmacology; D013552:Swine; D013696:Temperature; D013997:Time Factors
D000900:Anti-Bacterial Agents; D005520:Food Preservatives; D019346:Sodium Acetate; D048271:Chitosan; D019354:Sodium Lactate