The enzymatic release of glycosidically-bound terpenes in must

Simple item page
dc.contributor.advisorBotes, DPen_ZA
dc.contributor.authorStrauss, Lindie Heleneen_ZA
dc.date.accessioned2016-10-19T03:55:42Z
dc.date.available2016-10-19T03:55:42Z
dc.date.issued1989en_ZA
dc.descriptionBibliography: pages 79-86.en_ZA
dc.description.abstractFlavour in wines is perhaps the most important factor affecting wine quality, with monoterpenoids being among the compounds contributing to flavour. In grapes there exists glycosidically-bound forms of these monoterpenes, representing a latent source of aroma. This project is a study on the ability of different enzymes to release these monoterpenes in Muscat d'Alexandrie and Weisser Riesling grapes. Different commercial enzyme preparations were characterised with respect to their catalytic properties and fractionated by ion exchange chromatography in the most active fractions. Amongst those commercial preparations tested, Rohapect C was found to be the most effective at conditions prevalent during wine making. These purified fractions were added to the above mentioned grapes to determine their effect on the release of different monoterpenes. Even though the enzymes were active on synthetic substrates, limited release of terpenes from must could be detected. Possible causes for this apparent inability to release monoterpenes were investigated. Product inhibition due to the presence of high concentrations of glucose in the must appeared to be the main cause of limited enzyme activity. In an attempt to overcome this problem, glucose in the above mentioned cultivars was oxidised to gluconic acid by glucose oxidase, prior to attempting monoterpene release by Rohapect C. Although no marked increase in the release of total terpenes occured, a significant increase in the concentrations of some individual terpenes could be observed. The effect of this on wine quality remains to be ascertained.en_ZA
dc.identifier.apacitationStrauss, L. H. (1989). <i>The enzymatic release of glycosidically-bound terpenes in must</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Molecular and Cell Biology. Retrieved from http://hdl.handle.net/11427/22185en_ZA
dc.identifier.chicagocitationStrauss, Lindie Helene. <i>"The enzymatic release of glycosidically-bound terpenes in must."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Molecular and Cell Biology, 1989. http://hdl.handle.net/11427/22185en_ZA
dc.identifier.citationStrauss, L. 1989. The enzymatic release of glycosidically-bound terpenes in must. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Strauss, Lindie Helene AB - Flavour in wines is perhaps the most important factor affecting wine quality, with monoterpenoids being among the compounds contributing to flavour. In grapes there exists glycosidically-bound forms of these monoterpenes, representing a latent source of aroma. This project is a study on the ability of different enzymes to release these monoterpenes in Muscat d'Alexandrie and Weisser Riesling grapes. Different commercial enzyme preparations were characterised with respect to their catalytic properties and fractionated by ion exchange chromatography in the most active fractions. Amongst those commercial preparations tested, Rohapect C was found to be the most effective at conditions prevalent during wine making. These purified fractions were added to the above mentioned grapes to determine their effect on the release of different monoterpenes. Even though the enzymes were active on synthetic substrates, limited release of terpenes from must could be detected. Possible causes for this apparent inability to release monoterpenes were investigated. Product inhibition due to the presence of high concentrations of glucose in the must appeared to be the main cause of limited enzyme activity. In an attempt to overcome this problem, glucose in the above mentioned cultivars was oxidised to gluconic acid by glucose oxidase, prior to attempting monoterpene release by Rohapect C. Although no marked increase in the release of total terpenes occured, a significant increase in the concentrations of some individual terpenes could be observed. The effect of this on wine quality remains to be ascertained. DA - 1989 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1989 T1 - The enzymatic release of glycosidically-bound terpenes in must TI - The enzymatic release of glycosidically-bound terpenes in must UR - http://hdl.handle.net/11427/22185 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/22185
dc.identifier.vancouvercitationStrauss LH. The enzymatic release of glycosidically-bound terpenes in must. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Molecular and Cell Biology, 1989 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/22185en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Molecular and Cell Biologyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherTerpenesen_ZA
dc.subject.otherMusten_ZA
dc.subject.otherEnzymesen_ZA
dc.titleThe enzymatic release of glycosidically-bound terpenes in musten_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
thesis_sci_1989_strauss_lindie_helene.pdf
Size:
5.25 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Masters