title: Reduction of Escherichia coli O157:H7 on radish seeds by sequential application of aqueous chlorine dioxide and dry-heat treatment.
abstract: OBJECTIVE
  To assess the effectiveness of sequential treatments of radish seeds with aqueous chlorine dioxide (ClO(2) ) and dry heat in reducing the number of Escherichia coli O157:H7.
  
  
  RESULTS
  Radish seeds containing E. coli O157:H7 at 5.5 log CFU g(-1) were treated with 500 μg ml(-1) ClO(2) for 5 min and subsequently heated at 60 °C and 23% relative humidity for up to 48 h. Escherichia coli O157:H7 decreased by more than 4.8 log CFU g(-1) after 12 h dry-heat treatment. The pathogen was inactivated after 48 h dry-heat treatment, but the germination rate of treated seeds was substantially reduced from 91.2 ± 5.0% to 68.7 ± 12.3%.
  
  
  CONCLUSIONS
  Escherichia coli O157:H7 on radish seeds can be effectively reduced by sequential treatments with ClO(2) and dry heat. To eliminate E. coli O157:H7 on radish seeds without decreasing the germination rate, partial drying of seeds at ambient temperature before dry-heat treatment should be investigated, and conditions for drying and dry-heat treatment should be optimized.
  
  
  CONCLUSIONS
  This study showed that sequential treatment with ClO(2) and dry-heat was effective in inactivating large numbers of E. coli O157:H7 on radish seeds. These findings will be useful when developing sanitizing strategies for seeds without compromising germination rates.
authors.affiliation: Graduate School of Life Sciences and Biotechnology, Korea University, Seoul, Korea.
authors.forename: J
authors.initials: J
authors.lastname: Bang
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: L R
authors.initials: LR
authors.lastname: Beuchat
authors.forename: Y
authors.initials: Y
authors.lastname: Kim
authors.forename: J-H
authors.initials: JH
authors.lastname: Ryu
mesh_terms: D017606:Chlorine Compounds / Q000633:toxicity*; D015169:Colony Count, Microbial; D003890:Desiccation / Q000379:methods; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000254:growth & development; D018525:Germination; D006358:Hot Temperature; D010087:Oxides / Q000633:toxicity*; D031224:Raphanus / Q000382:microbiology*; D012639:Seeds / Q000382:microbiology; D014867:Water
chemical_list: D017606:Chlorine Compounds; D010087:Oxides; D014867:Water; C025109:chlorine dioxide