15D-11 |
Efficacy of electrolyzed oxidizing (EO) water for inactivation of Escherichia coli O157:H7 on strawberry and broccoli |
P. Tilly1, C. KIM2, and Y. C. Hung1. (1) Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, GA 30223, (2) Univesrity of Georgia, Griffin, GA 30223 Outbreaks of foodborne illness associated with fruits and vegetables in the world have increased consistently in the past decade. This study was undertaken to determine the efficacy of electrolyzed oxidizing (EO) water in eliminating Escherichia coli O157:H7 on strawberries and broccoli. Inoculated strawberry was treated with deionized water (control), EO water (23 and 55 mg/L of residual chlorine) and chlorinated water (55 mg/L of residual chlorine from Ca[OCl]2), either with or without ultrasonication. For the broccoli study, higher chlorine concentrations than the strawberry study were used (EO water containing 55 and 100 mg/L of residual chlorine and chlorinated water with 100 mg/L of residual chlorine). Different exposure times (1 and 5 min) and treatment temperatures (4 and 24ºC) were also evaluated on the fate of E. coli O157:H7 on the produce. Dipping fresh produce into EO water or chlorinated water did not completely eliminate E. coli O157:H7 on strawberry or broccoli although it significantly reduced the E. coli O157:H7 population. Treating inoculated strawberry with chlorinated water or EO water in conjunction with ultrasonication for 5 min reduced E. coli O157:H7 population by 1.8 and 1.9 log10 CFU/g, respectively. Dipping inoculated broccoli into chlorinated water or EO water in conjunction with ultrasonication for 5 min reduced the bacterial population by 1.8 and 2.2 log10 CFU/g, respectively. Significant difference between EO water treatment (2.2 log10 CFU/g) and chlorinated water treatment (1.8 log10 CFU/g) was observed. These results revealed that EO water was more effective on some of the treatment conditions than chlorinated water in killing E. coli O157:H7 on strawberry and broccoli.
Session 15D, Food Microbiology: Fruits and vegetables
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