Cellular and in-vitro models to assess antioxidant activities of seaweed extracts and the potential use of the extracts as ingredients

dc.check.embargoformatNot applicableen
dc.check.infoNo embargo requireden
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dc.contributor.advisorKerry, Joseph P.en
dc.contributor.advisorO'Brien, Nora M.en
dc.contributor.authorO'Sullivan, Anthoney Michael Naim
dc.contributor.funderMarine Instituteen
dc.contributor.funderDepartment of Agriculture, Food and the Marine, Irelanden
dc.date.accessioned2013-09-11T15:54:41Z
dc.date.available2013-09-11T15:54:41Z
dc.date.issued2013
dc.date.submitted2013
dc.description.abstractSeaweeds contain a range of antioxidant compounds such as polyphenols, carotenoids, sulphated polysaccharides and vitamins and have the potential to be used as ingredients in neutraceuticals. The antioxidant activity of crude 60% methanol extracts prepared from five Irish seaweeds, Ascophyllum nodosum, Laminaria hyperborea, Pelvetia canaliculata, Fucus vesiculosus and Fucus serratus were examined using in-vitro assays and a cell model system to determine the antioxidant activity of the extracts and their ability to protect against H2O2 and tert-BOOH-induced DNA damage and alterations in cellular antioxidant status in the human adenocarcinoma, Caco-2 cell line. To optimise the extraction of antioxidant compounds from seaweeds, an accelerated solvent extraction (ASE®) was used in combination with food grade solvents. The antioxidant activity of these extracts against H2O2 and tert-BOOH-induced DNA damage and alterations in cellular antioxidant status was also assessed. Extracts that exhibited the highest antioxidant activity, A. nodosum (100% water and 80% ethanol extracts) and F. vesiculosus (60% ethanol extract) were selected as ingredients for incorporation into fluid milk and yogurt at concentrations of 0.25% and 0.5%. The addition of the seaweed extracts to milk and yogurt did not affect the pH or shelf-life properties of the products. Seaweed addition did however significantly influence the colour properties of the milk and yogurt. Yellowness values were significantly higher in yogurts containing F. vesiculosus at both concentrations and A. nodosum (80% ethanol) at the 0.5% concentration. In milk, the F. vesiculosus (60% ethanol) and A. nodosum (80% ethanol) at both the 0.25% and the 0.5% concentrations had higher greenness and yellowness values than the milk containing A. nodosum (100% water). Sensory analysis revealed that appearance and flavour governed the overall acceptability of yogurts with the control yogurt, and yogurts containing A. nodosum (100% water) were the most preferred samples by panellists. However, in the milk trial the perception of a fishy taste was the determining factor in the negative perception of milk. The unsupplemented control and the milk containing A. nodosum (100% water) at a concentration of 0.5% were the most overall accepted milk samples by the sensory panellists. The antioxidant activity of the extracts in milk and yogurt remained stable during storage as determined by the in-vitro assays. Seaweed supplemented milk and yogurt were also subjected to an in-vitro digestion procedure which mimics the human digestive system. The milk and yogurt samples and their digestates were added to Caco-2 cells to investigate their antioxidant potential however neither the undigested or digested samples protected against H2O2-induced DNA damage in Caco-2 cells.en
dc.description.sponsorshipDepartment of Agriculture, Food and the Marine (NutraMara MFFRI/07/01)en
dc.description.statusNot peer revieweden
dc.description.versionAccepted Version
dc.format.mimetypeapplication/pdfen
dc.identifier.citationO'Sullivan, A.M.N. 2013. Cellular and in-vitro models to assess antioxidant activities of seaweed extracts and the potential use of the extracts as ingredients. PhD Thesis, University College Cork.en
dc.identifier.endpage230
dc.identifier.urihttp://hdl.handle.net/10468/1234
dc.language.isoenen
dc.publisherUniversity College Corken
dc.rights© 2013, Anthoney M. N. O'Sullivanen
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/3.0/en
dc.subjectAntioxidant activity of seaweed extractsen
dc.subject.lcshMarine algae as fooden
dc.subject.lcshSeaweeden
dc.subject.lcshAntioxidantsen
dc.thesis.opt-outfalse*
dc.titleCellular and in-vitro models to assess antioxidant activities of seaweed extracts and the potential use of the extracts as ingredientsen
dc.typeDoctoral thesisen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhD (Food Science and Technology)en
ucc.workflow.supervisornob@ucc.ie*
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