Photochemical Protection of Riboflavin and Tetrapyrroles with Light Scattering Technology

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dc.contributor.authorHamilton, Jeffrey Hunten
dc.contributor.committeechairDuncan, Susan E.en
dc.contributor.committeememberWebster, Janet B.en
dc.contributor.committeememberO'Keefe, Sean F.en
dc.contributor.departmentFood Science and Technologyen
dc.date.accessioned2017-04-04T19:49:24Zen
dc.date.adate2012-12-06en
dc.date.available2017-04-04T19:49:24Zen
dc.date.issued2012-06-18en
dc.date.rdate2016-09-30en
dc.date.sdate2012-07-02en
dc.description.abstractThe effectiveness of titanium dioxide (TiO?) in polyethylene films at preventing the photooxidation of riboflavin in a model solution was evaluated. Five different TiO? loads (0.5-8.0 wt%), each at 3 different thicknesses (50-100 um) were evaluated. A photochemical reactor, equipped with a 350W mercury lamp, provided full spectrum light or narrow bandwidth wavelength exposure, using filters allowing transmission at 25 nm wavebands at maximum peak height at 450, 550, or 650 nm. Riboflavin concentration was measured by HPLC over 8 hours of exposure. Increased TiO? load and thickness significantly affected riboflavin photooxidation (p<0.05). TiO? load had more influence on protection provided to riboflavin than did film thickness. Film opacity correlated linearly with decreased photooxidation (R2 of 0.831 & 0.783 for full spectrum and 450 nm bandpass-filter sets, respectively). Riboflavin photooxidation proceeded most rapidly with the full spectrum exposure (light intensity 118 ° 17.3 mW). Photooxidation occurred in the 450 nm bandpass-filter, but not for 550 & 650 nm sets (light intensities of 2.84 °0.416, 3.36 °0.710, and 0.553 ° 0.246 mW, respectively). Effect of fluorescent light-exposure (2020-1690 lux) on the same system was monitored over 2 days. Riboflavin degradation in the photoreactor proceeded ~300 times faster than under fluorescent lighting. Riboflavin degradation was found to significantly increase with the addition of chlorophyll-like tetrapyrroles (p<0.05). Riboflavin was found to significantly decrease the degradation rate of the tetrapyrroles pyropheophytin a and pheophytin a (p<0.05). The decrease in rate was not significant for chlorophyll a (p>0.05).en
dc.description.degreeMaster of Science in Life Sciencesen
dc.identifier.otheretd-07022012-170502en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-07022012-170502/en
dc.identifier.urihttp://hdl.handle.net/10919/76811en
dc.language.isoen_USen
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectTitanium Dioxideen
dc.subjectMilken
dc.subjectDairyen
dc.subjectOxidationen
dc.subjectChlorophyllen
dc.titlePhotochemical Protection of Riboflavin and Tetrapyrroles with Light Scattering Technologyen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineFood Science and Technologyen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Science in Life Sciencesen

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