Decontamination of Escherichia coli O157:H7 and Salmonella enterica on blueberries using ozone and pulsed UV-light

J Food Sci. 2007 Nov;72(9):M391-6. doi: 10.1111/j.1750-3841.2007.00517.x.

Abstract

Efficacy of gaseous ozone, aqueous ozone, and pulsed UV-light was evaluated for the purpose of decontaminating blueberries artificially contaminated with either Escherichia coli O157:H7 or Salmonella. Blueberries were exposed to 4 different gaseous ozone treatments: continuous ozone exposure, pressurized ozone exposure, and 2 combined treatments. Maximum reductions of Salmonella and E. coli O157:H7 after 64-min pressurized or 64-min continuous exposure were 3.0 and 2.2 log(10) CFU/g, respectively. Aqueous ozone experiments were conducted at 20 degrees C and 4 degrees C and zero plate counts were observed for E. coli O157:H7 and Salmonella after 64 min of ozone exposure at 20 degrees C. Finally, pulsed UV-light was evaluated at 3 different distances from the light. Maximum reductions of 4.3 and 2.9 log(10) CFU/g were observed at 8 cm from the light after 60 s of treatment for Salmonella and E. coli O157:H7, respectively. A sensory analysis as well as color analysis was performed on blueberries from each treatment agent; neither analysis detected a difference between treated and untreated blueberries. The results presented in this study indicate that ozone and pulsed UV-light are good candidates for decontamination of blueberries.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Analysis of Variance
  • Blueberry Plants / drug effects
  • Blueberry Plants / microbiology*
  • Blueberry Plants / radiation effects
  • Colony Count, Microbial
  • Color
  • Consumer Behavior
  • Escherichia coli O157 / drug effects
  • Escherichia coli O157 / growth & development*
  • Escherichia coli O157 / radiation effects
  • Food Contamination / prevention & control*
  • Food Handling / methods
  • Food Irradiation / methods
  • Food Microbiology*
  • Humans
  • Oxidants, Photochemical / pharmacology
  • Ozone / pharmacology*
  • Salmonella enterica / drug effects
  • Salmonella enterica / growth & development*
  • Salmonella enterica / radiation effects
  • Sensation / drug effects
  • Sensation / physiology
  • Treatment Outcome
  • Ultraviolet Rays*

Substances

  • Oxidants, Photochemical
  • Ozone