Graduate Thesis Or Dissertation
 

Efficacy of electrolyzed oxidizing water and ozonated water for microbialdecontamination of fresh strawberries (Fragaria x ananassa)

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/ff365815m

Descriptions

Attribute NameValues
Creator
Abstract
  • The objectives of this project were to evaluate the efficacies of electrolyzed oxidizing (EO) and ozonated waters as antimicrobial agents for enhancing the microbiological safety of fresh strawberries (Fragaria x ananassa). The influence of sodium chloride (NaCl) concentrations used for preparing EO water was evaluated on their bactericidal activities against naturally occurring aerobic mesophiles on strawberries with a contact time of 5, 10, or 15 min. EO water and ozonated water containing about 1.90 ppm ozone were evaluated and compared with sodium hypochlorite (NaOCl) solution on their capabilities to inactivate and control the growth of Listeria monocytogenes and Escherichia coli O157:H7 inoculated onto strawberries stored at 4 ± 1 °C for up to 15 d, respectively. Post-treatment neutralization of fruit surfaces by washing was also investigated. More than 2 log₁₀ CFU/g reduction of mesophilic aerobic bacteria was achieved in samples washed for 10 or 15 min in EO water prepared from 0.10% (w/v) NaCl solution. Bactericidal activity of treatment solutions against L. monocytogenes and E. coli O157:H7 was not affected by post-treatment neutralization, and their effectiveness against both pathogens in whole fruit tissues did not significantly increase with increasing exposure time. The EO water had an equivalent antibacterial effect as compare with NaOCl in eliminating L. monocytogenes and E. coli O157:H7 on whole strawberry tissues. Fruit surfaces washing with distilled water resulted in 1.90 and 1.27 log₁₀ CFU/ml of rinse fluid reduction of L. monocytogenes and E. coli O157:H7, respectively, whereas ≥ 2.60 log₁₀ CFU/ml of rinse fluid reduction of L. monocytogenes and up to 2.35 and 3.12 log reduction of E. coli O157:H7 were observed on fruit surfaces washed with EO water and NaOCl solution, respectively. However, EO water and NaOCl solution treatments did not exhibit a higher microbicidal activity than water treatment during refrigeration storage. The ozone treatment on inoculated strawberries was not remarkably effective in removing and eliminating pathogens on the whole fruit tissues, but the populations of L. monocytogenes and E. coli O157:H7 were significantly decreased after ozone treatment regardless of the exposure time. The number of L. monocytogenes and E. coli O157:H7 on fruit surfaces was decreased by 2.17 and 2.02 log₁₀ CFU/ml of rinse fluid, respectively, after washing with ozonated water for 10 min.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
File Format
File Extent
  • 541268 bytes
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items