title: Antimicrobial Effects of Nisin, Essential Oil, and γ-Irradiation Treatments against High Load of Salmonella typhimurium on Mini-carrots.
abstract: This study aimed at using essential oil (EO) alone or combined EO with nisin and γ-irradiation to control Salmonella Typhimurium during the refrigerated storage of mini-carrots. Peeled mini-carrots were inoculated with S. Typhimurium at a final concentration of approximately 7 log CFU/g. Inoculated samples were coated by 5 different coating solutions: (i) nisin solution at final concentration of 10(3) IU/mL; (ii) mountain savory EO solution at 0.35%; (iii) carvacrol solution at 0.35%; (iv) mountain savory EO at 0.35% plus nisin solution of 10(3) IU/mL; or (v) carvacrol at 0.35% plus nisin solution of 10(3) IU/mL. Coated mini-carrots were then irradiated at 0.5 or 1.0 kGy and compared to an unirradiated control sample. Samples were kept at 4 °C and microbial analyses were conducted at days 1, 3, 6, and 9. The results showed that mini-carrots coated by carvacrol plus nisin solution or mountain savory EO plus nisin solution in combination with irradiation at 1.0 kGy completely eliminated S. Typhimurium to under the detection limit during the storage. Thus, the combined treatments using carvacrol plus nisin or mountain savory EO plus nisin coating solution and irradiation at 1.0 kGy could be used as an effective method for controlling S. Typhimurium in mini-carrots.
  
  
  CONCLUSIONS
  This study shows the effect of using γ irradiation at low dose (1 kGy) to reduce significantly the growth of Salmonella typhimurium in mini-carrots. It also shows that combination of nisin, essential oils with γ irradiation have the best antibacterial effects against S. Typhimurium during the storage of mini-carrots. The results can be used for practical application in food industry in terms of food safety.
authors.affiliation: Research Laboratories in Sciences Applied to Food, Canadian Irradiation Center (CIC), INRS-Inst. Armand-Frappier, Univ. of Quebec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada.
authors.forename: Aude
authors.initials: A
authors.lastname: Ndoti-Nembe
authors.affiliation: Research Laboratories in Sciences Applied to Food, Canadian Irradiation Center (CIC), INRS-Inst. Armand-Frappier, Univ. of Quebec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada.|Dept. of Food Bioscience and Technology, Korea Univ, Seoul, 136-701, Korea.
authors.forename: Khanh Dang
authors.initials: KD
authors.lastname: Vu
authors.affiliation: Dept. of Food Bioscience and Technology, Korea Univ, Seoul, 136-701, Korea.
authors.forename: Jaejoon
authors.initials: J
authors.lastname: Han
authors.affiliation: INRS-Inst. Armand-Frappier, Univ. of Quebec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Doucet
authors.affiliation: Research Laboratories in Sciences Applied to Food, Canadian Irradiation Center (CIC), INRS-Inst. Armand-Frappier, Univ. of Quebec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada.
authors.forename: Monique
authors.initials: M
authors.lastname: Lacroix
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D058491:Bacterial Load / Q000187:drug effects / Q000528:radiation effects; D000081007:Cymenes; D018552:Daucus carota / Q000382:microbiology*; D005506:Food Contamination / Q000517:prevention & control; D005516:Food Microbiology; D005720:Gamma Rays; D039821:Monoterpenes / Q000494:pharmacology; D009561:Nisin / Q000494:pharmacology*; D009822:Oils, Volatile / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000528:radiation effects*
chemical_list: D000900:Anti-Bacterial Agents; D000081007:Cymenes; D039821:Monoterpenes; D009822:Oils, Volatile; D009561:Nisin; C073316:carvacrol; C102526:nisin A
keywords: Salmonella Typhimurium; carvacrol; mountain savory essential oil; nisin; γ irradiation