Bacterial inhibition by electrolyzed oxidizing water and application to disinfection of sprout seeds Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/cr56n418s

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • Alfalfa sprouts have been implicated in several salmonellosis outbreaks in recent years. Electrolysis of a NaCl solution generates, in the anode side of a two-chamber electrolyzer, acidic electrolyzed oxidizing (EO) water which contains Cl₂, HOC1, dissolved oxygen, and it is characterized by a low pH and a high oxidation reduction potential (ORP). The disinfectant effects of EO water against Salmonella enterica both in an aqueous system and on artificially contaminated alfalfa seeds were determined. EO water (pH 2.54 to 2.38, and ORP +1083 to +1092 mV) exhibited strong potential for the inactivation of S. enterica in an aqueous system (producing a reduction of at least 6.6 log CFU/ml). Treatment of artificially contaminated alfalfa seeds with EO water at a seed-to-EO water ratio of 1:100 for 15 and 60 min significantly reduced Salmonella populations by 2.04 and 1.96 log CFU/g, respectively (P < 0.05), while a Butterfield's buffer wash decreased Salmonella populations by 0.18 and 0.23 log CFU/g, respectively. Germination of seeds was not significantly affected (P > 0.05) by a treatment for up to 60 min in electrolyzed water. Further studies were undertaken to investigate whether •OH radical species are present in EO water or are formed when EO water reacts with iron ions. Electron spin resonance spectroscopy (ESR) coupled with the spin trapping technique was used for the detection of free radicals. The DMPO-OH spin adduct, characteristic to •OH radicals, was not observed. In the presence of DMPO (5,5-dimethyl-l-pyrroline-N-oxide), the reactions of EO water with Fe³⁺ and Fe²⁺ yielded the spin adduct DMPO-OH. However, the addition of •OH radical scavengers (ethanol, methanol, and mannitol) to the reaction mixture, did not reduce the DMPO-OH signal nor generated the characteristic DMPO-alkyl spin adducts. This indicated that the DMPO-OH signal was due to a nucleophilic addition of water to DMPO and not to trapping of OH radicals. Addition of DMPO to EO water, generated an ESR spectrum identical with that of 5,5-dimethyl-2-pyrrolidone- N-oxyl (DMPOX). Hypochlorous acid, generated in the anode chamber, is proposed to oxidize the spin trap DMPO with the formation of DMPOX.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 24-bit Color) using Scamax Scan+ V.1.0.32.10766 on a Scanmax 412CD by InoTec in PDF format. LuraDocument PDF Compressor V.5.8.71.50 used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2012-01-23T20:26:16Z (GMT) No. of bitstreams: 1 STANSILVIA2003.pdf: 1213417 bytes, checksum: f35704c28122b19cbbff60737dbf3cd5 (MD5)
  • description.provenance : Made available in DSpace on 2012-01-26T16:27:29Z (GMT). No. of bitstreams: 1 STANSILVIA2003.pdf: 1213417 bytes, checksum: f35704c28122b19cbbff60737dbf3cd5 (MD5) Previous issue date: 2003-12-11
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2012-01-26T16:27:29Z (GMT) No. of bitstreams: 1 STANSILVIA2003.pdf: 1213417 bytes, checksum: f35704c28122b19cbbff60737dbf3cd5 (MD5)
  • description.provenance : Submitted by Erin Clark (ecscannerosu@gmail.com) on 2012-01-23T18:02:33Z No. of bitstreams: 1 STANSILVIA2003.pdf: 1213417 bytes, checksum: f35704c28122b19cbbff60737dbf3cd5 (MD5)

Relationships

In Administrative Set:
Last modified: 08/15/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items