Yeast Communities Influence Regional Character in New Zealand Pinot Noir

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dc.contributor.advisor Goddard, M en
dc.contributor.advisor Knight, S en
dc.contributor.author Hawkins, Diana en
dc.date.accessioned 2019-10-15T04:21:43Z en
dc.date.issued 2019 en
dc.identifier.uri http://hdl.handle.net/2292/48541 en
dc.description Full Text is available to authenticated members of The University of Auckland only. en
dc.description.abstract Recent studies have suggested that yeast and other micro organisms may contribute to a wine's regional distinctiveness. This study represents the first attempt to experimentally test how yeast communities, consisting of multiple isolates and species, contribute to regional wine attributes in a controlled environment. It sought to explore the following questions using New Zealand Pinot Noir as a medium: • Are yeast communities present in the early stages of uninoculated Pinot Noir fermentations regionally distinct in New Zealand? • Do these yeast communities - including non-Saccharomyces species - modulate wine aroma and/or fermentation kinetics in a regionally distinct manner? • Is there a community effect on fermentation kinetics and/or wine aroma? New methodologies for preparing a mixed species inoculum from regional yeast communities in a repeatable manner were optimised. Synthetic yeast communities comprised of natural isolates were successfully collated for 17 vineyard sites across Martinborough, Marlborough and Central Otago in New Zealand. This allowed community contribution to regional character to be explored in a controlled setting for the first time. The species present during the early stages of uninoculated New Zealand Pinot Noir fermentations were identified; however, we were unable to reject the null hypothesis of no difference in species composition between the three geographic regions since regional differences were not found in the types of species present during the early stages of fermentation. Wines were produced using these yeast communities and 28 yeast-derived aroma compounds were measured via Headspace Solid-Phase Dynamic Extraction Coupled with Gas Chromatography-Mass Spectrometry. Yeast community composition was found to have a significant impact on wine sensory attributes and fermentation kinetic variables. The region the communities were from was also found to have a significant impact on wine sensory attributes; however, the impact on fermentation kinetics was mixed. These results allowed us to reject the two remaining null hypotheses and accept the alternative hypotheses that yeast communities modulate wine aroma in a regionally distinct manner; and that the composition of these communities also modulates wine aroma and fermentation kinetics. This suggests that there is a microbial component to regional character for New Zealand Pinot Noir. en
dc.publisher ResearchSpace@Auckland en
dc.relation.ispartof Masters Thesis - University of Auckland en
dc.relation.isreferencedby UoA99265184013702091 en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. en
dc.rights Restricted Item. Full Text is available to authenticated members of The University of Auckland only. en
dc.rights.uri https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm en
dc.rights.uri http://creativecommons.org/licenses/by-nc-sa/3.0/nz/ en
dc.title Yeast Communities Influence Regional Character in New Zealand Pinot Noir en
dc.type Thesis en
thesis.degree.discipline Wine Science en
thesis.degree.grantor The University of Auckland en
thesis.degree.level Masters en
dc.rights.holder Copyright: The author en
pubs.elements-id 784123 en
pubs.record-created-at-source-date 2019-10-15 en


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http://creativecommons.org/licenses/by-nc-sa/3.0/nz/ Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by-nc-sa/3.0/nz/

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