title: Effect of antimicrobial coatings on the radiosensitization of Escherichia coli, Salmonella typhimurium, and Listeria monocytogenes in fresh broccoli.
abstract: Radiosensitization of Listeria monocytogenes, Escherichia coli, Salmonella Typhimurium, and aerobic microflora was evaluated in broccoli florets coated by antimicrobial coatings and treated with different doses of γ-radiation. Broccoli florets were inoculated with aerobic microflora isolated from broccoli and with pathogenic bacteria (L. monocytogenes, E. coli, and Salmonella Typhimurium) at 10(6) CFU/ml. Inoculated florets were then coated with methylcellulose-based coating containing various mixtures of antimicrobial agents: organic acids plus lactic acid bacteria (LAB metabolites), organic acids plus citrus extract, organic acids plus citrus extract plus spice mixture, and organic acids plus rosemary extract. Coated florets were irradiated with various doses (0 to 3.3 kGy), and microbial analyses were conducted to calculate the D(10)-value and relative sensitivity. All antimicrobial coatings had almost the same effect of increasing the radiosensitivity of L. monocytogenes (from 1.31 to 1.45 times) to γ-irradiation. The coating containing organic acid plus citrus extract was the most efficient formulation for increasing the radiosensitization of E. coli and aerobic microflora, by 2.40 and 1.76 times, respectively, compared with the control without the antimicrobial coating. The coating containing organic acids plus LAB metabolites was the most effective formulation for increasing the radiosensitization (by 2.4 times) of Salmonella Typhimurium. Results suggest that the spice extract, when mixed with organic acids and citrus extract, might protect E. coli and aerobic microflora from the effects of γ-irradiation.
authors: Canadian Irradiation Center, Research Laboratories in Sciences Applied to Food, Institut National de la Recherche Scientifique, Institut Armand-Frappier, 531 Boulevard des Prairies, Laval, Québec, Canada H7V 1B7.
authors: P N
authors: PN
authors: Takala
authors: K D
authors: KD
authors: Vu
authors: S
authors: S
authors: Salmiéri
authors: M
authors: M
authors: Lacroix
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001937:Brassica / Q000382:microbiology*; D019343:Citric Acid / Q000494:pharmacology; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects; D005506:Food Contamination / Q000517:prevention & control; D005514:Food Irradiation; D005516:Food Microbiology; D005720:Gamma Rays; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects; D012486:Salmonella typhimurium / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects
chemical_list: D000900:Anti-Bacterial Agents; D019343:Citric Acid