2026-09-21T13:09:18Zhttps://digital.library.adelaide.edu.au/server/oai/request

oai:digital.library.adelaide.edu.au:2440/1416122024-07-16T07:07:45Zcom_2440_14759col_2440_14760

Wilkinson, Kerry Wollan, David (The Australian Research Council Training Centre for Innovative Wine Production; VAF Memstar) Muhlack, Richard (Department of Wine Science and Waite Research Institute; The Australian Research Council Training Centre for Innovative Wine Production) Bindon, Keren (The Australian Wine Research Institute) Angela, Stephanie School of Agriculture, Food and Wine 2024 https://hdl.handle.net/2440/141612 Ultrafiltration (UF) is a membrane-based technology that separates liquid feed by a molecular size principle, producing permeate with smaller molecules and retentate with larger molecules. Widely used in water treatment, it finds application in the food and beverage industries for processes such as clarification, specific feed constituents management, sterilisation, and purification. However, challenges arise due to variations in feed, influencing outcomes based on feed composition and operational parameters. To date, potential applications of ultrafiltration in the wine industry and wine science have not been extensively explored. Therefore, this PhD project investigates the feasibility of applying UF technology in winemaking to improve sensory attributes such as colour, texture, mouthfeel, aroma, and flavour, possibly increasing the volume of highly sought-after wines. Comprising five intertwined projects, the initial screening project in Chapter 2 focuses on understanding the impact of UF on red and white wines and exploring the potential utility of each fraction (permeate and retentate) in winemaking. Subsequently, the addition of retentate derived from white wine to Pinot Noir ferments to improve colour stability and density and positively influence phenolic compounds for enhanced sensory quality is investigated in Chapter 3. Chapter 4 describes blending the UF wine fractions to enhance wine quality post-filtration and after re-blending. Chapter 5 explores the addition of white wine retentate to commercial red and white no or low alcohol (NOLO) wines to compensate for the texture, mouthfeel, and aroma loss associated with the de-alcoholisation process and the absence of alcohol in the resulting product. Key findings reveal optimised UF parameters (10 kDa and 90-95% permeation degree) suitable for processing white wine, while the permeate derived from red wine is deemed commercially unacceptable as red wine due to the loss of essential components (e.g. colour). Adding white retentate to Pinot Noir ferments and wine increases production yield without significant sensory changes. The 5% (v/v) post-ferment retentate addiction treatment significantly increases colour density and stability despite mild dilution and possible tannin- protein precipitation effect. Blending retentate and permeate fractions at different rates from the third project demonstrates positive effects on red wine, yet a high retentate concentration requirement hinders economic feasibility. Adding white wine retentate to white NOLO wine increases phenolic compounds, tannins, and colour in compositions, but diluted red NOLO wine fails to address the loss of texture and mouthfeel due to alcohol removal. In conclusion, UF technology proves advantageous in certain winemaking applications, particularly in increased volumes of Pinot Noir and other highly sought-after wines without significant differences and produced drinkable white wine-derived permeate. While UF aids in managing phenolic compounds, limitations exist, particularly in understanding molecular-level phenomena and assumptions regarding membrane fouling, precipitation, dilution, and membrane absorption. The findings of this doctoral study have potential for prospective research endeavours. Future research should investigate membrane fouling and macromolecule precipitation in wine filtration at the molecular level. Additionally, there is a need for a tailored techno-economic analysis specific to the wine industry, which can offer vital insights for informed decision-making on the adoption of UF technology and its integration into commercial-scale processes. This research enhances understanding of UF technology in winemaking, supporting informed industry decisions for process improvement. Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food, and Wine, 2024 en Membranes Technology Wine Phenolic Wine Macromolecules Wine Sensory Wine Quality Enhancement Evaluating Winemaking Applications of Ultrafiltration Thesis This electronic version is made publicly available by the University of Adelaide in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. This thesis may incorporate third party material which has been used by the author pursuant to Fair Dealing exceptions. If you are the owner of any included third party copyright material you wish to be removed from this electronic version, please complete the take down form located at: http://www.adelaide.edu.au/legalsopen.access