Evaluation of the Antioxidant and Biological Properties of Muscadine Grape Seed Extracts

dc.contributor.advisorDr. Leon Boyd, Committee Chairen_US
dc.contributor.authorDansby, Montrekaen_US
dc.date.accessioned2010-04-02T19:11:45Z
dc.date.available2010-04-02T19:11:45Z
dc.date.issued2007-12-14en_US
dc.degree.disciplineFood Scienceen_US
dc.degree.leveldissertationen_US
dc.degree.namePhDen_US
dc.description.abstractThe objectives of this research were i) to optimize extraction of phenolic compounds from muscadine grape seeds using food grade solvents, ii) to characterize and quantify the phenolic compounds present in Carlos muscadine grape seed extracts, iii) to assess the oxidative stability of the grape seed extract, iv) to evaluate the antimicrobial activity of the optimal muscadine grape seed extract, and v) to evaluate the effect of muscadine grape seed extract on MCF-10A breast cells. Carlos muscadine grape seeds were manually removed from the skin and pulp, then freeze-dried or oven-dried. Phenolic compounds were extracted from muscadine grape seeds using a Dionex Accelerated Solvent Extractor 200 following a two factor composite design. The two factors were solvent and temperature. Ethanol in combination with water and ethyl acetate in combination with water were evaluated in this research. Solvent percentages ranged from 35% to 95% and temperature ranged from 75C to 150C. Optimal extraction conditions were determined using the Folin-Ciocalteu and oxygen radical absorbance capacity assays. Identification and quantification of the phenolic compounds were determined by high performance liquid chromatography with mass spectroscopy. The optimal extraction conditions for the highest recovery of phenolic compounds consisted of the freeze-dried seeds extracted with 65% ethanol and 35% water at 150°C, with total phenolic and oxygen radical absorbance capacity values of 5.87 mg GAE⁄g and 60.32 M-TE⁄g of seeds, respectively. The four major phenolic compounds quantified in the muscadine grape seed extract were epicatechin, catechin, gallic acid and ellagic acid. Oxidative stability index of the muscadine grape seed extract resulted in an induction period of 4.6 hours. In the antimicrobial study, both muscadine grape seed extract and ellagic acid inhibited the growth of E. coli 0157:H7, Listeria monocytogenes, and Salmonella typhimurium at 104 cfu⁄ml. These research findings show that muscadine grape seed extracts contain phytochemicals with antioxidant and antimicrobial properties that can be used in applications including food ingredients, food supplements and other nutraceutical applications.en_US
dc.identifier.otheretd-08202006-105509en_US
dc.identifier.urihttp://www.lib.ncsu.edu/resolver/1840.16/5328
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 NC State University 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.subjectantioxidantsen_US
dc.subjectanti-microbialen_US
dc.subjectanti-carcinogenicen_US
dc.subjectgrape seeden_US
dc.subjectpolyphenolsen_US
dc.subjectmuscadinesen_US
dc.titleEvaluation of the Antioxidant and Biological Properties of Muscadine Grape Seed Extractsen_US

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