title: Antimicrobial effects of essential oils, nisin, and irradiation treatments against Listeria monocytogenes on ready-to-eat carrots.
abstract: The study aimed at using essential oil (EO) alone or combined EO with nisin and low dose γ-irradiation to evaluate their antibacterial effect against Listeria monocytogenes during storage of carrots at 4 °C. Minicarrots were inoculated with L. monocytogenes at a final concentration of approximately 7 log CFU/g. Inoculated samples were coated by nisin at final concentration of 10(3) International Unit (IU)/mL or individual mountain savory EO or carvacrol at final concentration of 0.35%, w/w) or nisin plus EO. The samples were then irradiated at 0, 0.5, and 1.0 kGy. The treated samples were kept at 4 °C and microbial analysis of samples were conducted at days 1, 3, 6, and 9. The results showed that coating carrots by carvacrol plus nisin or mountain savory plus nisin and then irradiating coated carrots at 1 kGy could reduce L. monocytogenes by more than 3 log at day 1 and reduced it to undetectable level from day 6. Thus, the combined treatments using nisin plus carvacrol or nisin plus mountain savory and irradiation at 1.0 kGy could be used as an effective method for controlling L. monocytogenes in minicarrots.
authors: Research Laboratories in Sciences Applied to Food, Canadian Irradiation Center (CIC), INRS-Institut Armand-Frappier, Univ. of Quebec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada.
authors: Aude
authors: A
authors: Ndoti-Nembe
authors: Khanh Dang
authors: KD
authors: Vu
authors: Nicolas
authors: N
authors: Doucet
authors: Monique
authors: M
authors: Lacroix
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000081007:Cymenes; D018552:Daucus carota / Q000382:microbiology*; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D005720:Gamma Rays; D006801:Humans; D008089:Listeria monocytogenes / Q000187:drug effects / Q000528:radiation effects; D039821:Monoterpenes / Q000494:pharmacology; D009561:Nisin / Q000494:pharmacology*; D009822:Oils, Volatile / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology; D031362:Satureja / Q000737:chemistry; D014675:Vegetables / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D000081007:Cymenes; D039821:Monoterpenes; D009822:Oils, Volatile; D010936:Plant Extracts; D009561:Nisin; C073316:carvacrol
keywords: Gamma irradiation; Listeria monocytogenes; carvacrol; minicarrots; mountain savory essential oil