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dc.contributor.authorMcKinney, Julieen
dc.date.accessioned2014-03-14T20:09:18Zen
dc.date.available2014-03-14T20:09:18Zen
dc.date.issued2008-03-28en
dc.identifier.otheretd-04102008-181835en
dc.identifier.urihttp://hdl.handle.net/10919/26756en
dc.description.abstractFoodborne illnesses caused by Listeria monocytogenes have long been associated with ready-to-eat (RTE) meats contaminated after the primary thermal process has been applied. It is believed that brine solutions used to chill cooked RTE products may serve as a reservoir for L. monocytogenes becoming a potential point of post-processing contamination for RTE meats. Re-circulating ultraviolet light (UV) systems are being used to inactivate L. monocytogenes in chill brines; however very little has been reported on the dose response of healthy and stressed L. monocytogenes to UV in brine solutions. The objectives of this research were to determine 1) minimum dose of UV required to inactivate L. monocytogenes in distilled water, fresh brine, undiluted spent brine, and diluted spent brine, 2) if adaptation to food processing stresses affects the dose response, and 3) if the acquisition of antibiotic resistance mechanisms provides resistance to ultraviolet light 4) effect of stress adaptation on survival in brine solutions. After UV exposure, populations were reduced as follows from greatest to least: water > fresh brine > 5% spent brine > 35% spent brine > 55% spent brine > 100% spent brine (P â ¤ 0.05). There were no population differences between acid stressed and antibiotic resistant or healthy and heat shocked (P > 0.05). However, acid-stressed and sulfanilamide-resistant were more resistant to UV light than healthy and heat shocked L. monocytogenes (P â ¤ 0.05). Survival in brine solutions (no UV) followed the trend, from greatest to least (P â ¤ 0.05): sulfanilamide-resistant > acid-stressed > healthy > heat-shocked. Population estimates decreased from initial inoculation to final sampling for each cell type suspended in spent brine (P â ¤ 0.05), but only healthy and heat- shocked cells suspended in fresh brine were significantly reduced (P â ¤ 0.05). Knowledge of UV dosing required to control L. monocytogenes in brines used during RTE meat processing, and a greater understanding of the interactions that may influence dose will aid manufacturers in establishing appropriate food safety interventions for these products.en
dc.publisherVirginia Techen
dc.relation.haspartDissertation4-24-08_Combined.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectacid adaptationen
dc.subjectheat shocken
dc.subjectstress responseen
dc.subjectbrineen
dc.subjecturidineen
dc.subjectchemical actinometryen
dc.subjectantibiotic resistanceen
dc.subjectultraviolet lighten
dc.subjectListeria monocytogenesen
dc.titleMinimum Ultraviolet Light Dose Determination and Characterization of Stress Responses that Affect Dose for Listeria monocytogenes Suspended in Distilled Water, Fresh Brine, and Spent Brineen
dc.typeDissertationen
dc.contributor.departmentFood Science and Technologyen
dc.description.degreePh. D.en
thesis.degree.namePh. D.en
thesis.degree.leveldoctoralen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.disciplineFood Science and Technologyen
dc.contributor.committeechairWilliges, Robert C.en
dc.contributor.committeememberBoardman, Gregory D.en
dc.contributor.committeememberEifert, Joseph D.en
dc.contributor.committeememberSumner, Susan S.en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-04102008-181835/en
dc.date.sdate2008-04-10en
dc.date.rdate2008-04-29en
dc.date.adate2008-04-29en


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