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dc.contributor.authorSchurman, John Jacksonen_US
dc.date.accessioned2014-03-14T20:42:29Z
dc.date.available2014-03-14T20:42:29Z
dc.date.issued2001-07-18en_US
dc.identifier.otheretd-08022001-104536en_US
dc.identifier.urihttp://hdl.handle.net/10919/34302
dc.description.abstractThe antibacterial efficacy of hydrogen peroxide treatments in four fruit juices was determined. Preservative free apple cider, white grape, and purple grape juice were inoculated with ~ 6.4 log CFU/ml of a five strain, acid adapted, nalidixic acid resistant E. coli O157:H7 cocktail. Orange juice was inoculated with a comparable Salmonella spp. cocktail. In the first study, 0.017% and 0.012% H2O2 was added in combination with 0.1% and 0.3% of the dominant organic acid (OA) to 4oC and 25oC juices, with samples taken each day for 21 days. H2O2 was a significant factor in all juices (p < 0.05) except white grape (lack of data), and both 0.017% H2O2 treatments reduced counts in apple cider, orange juice, and white grape to undetectable numbers within 48 hrs as cultured on tryptone soy agar + 0.05% nalidixic acid (TSAN). Treatments in purple grape juice were less effective overall, and more dependent on OA concentration (p < 0.001) than H2O2. There were instances where bacterial survival in apple cider, purple grape, and orange juice continued for 21 days after treatment, and sometimes outlasted the control. These occurrences were dependent on temperature (25oC) and H2O2 (0.012%), but not on OA. However, OA concentration was a significant factor (p < 0.05) overall in apple cider and purple grape juice, but not in orange juice. In the second study, 0.015% and 0.03% H2O2 was added to 10, 25, and 40oC apple cider and orange juice inoculated with 6.4 log CFU/ml E. coli O157:H7 and Salmonella spp. respectively. Only 0.03% H2O2 was effective in reducing counts to undetectable numbers in both juices. However, both temperature and H2O2 were significant factors (p < 0.0001) in bacterial destruction, with 0.03% H2O2 at 40oC giving undetectable numbers at < 3 and < 6 hours in orange juice and apple cider respectively. It has been demonstrated that at ~ > 0.017%, H2O2 can provide a 5 log reduction of these pathogens in fruit juice. Increasing temperature and organic acid concentration can improve its rate of effectiveness in certain juices. However, sensory concerns may negate its use in some products.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartJohnSchurman.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectSalmonellaen_US
dc.subjectFruit Juiceen_US
dc.subjectEscherichia coli O157:H7en_US
dc.subjectOrganic Acidsen_US
dc.subjectHydrogen Peroxideen_US
dc.titleAntibacterial Activity of Hydrogen Peroxide Against Escherichia Coli O157:H7 and Salmonella Spp. in Fruit Juices, Both Alone and in Combination With Organic Acidsen_US
dc.typeThesisen_US
dc.contributor.departmentFood Science and Technologyen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineFood Science and Technologyen_US
dc.contributor.committeechairSumner, Susan S.en_US
dc.contributor.committeememberEifert, Joseph D.en_US
dc.contributor.committeememberMarcy, Joseph E.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08022001-104536/en_US
dc.date.sdate2001-08-02en_US
dc.date.rdate2002-08-02
dc.date.adate2001-08-02en_US


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