terclim by ICS banner
IVES 9 IVES Conference Series 9 EVALUATING WINEMAKING APPLICATIONS OF ULTRAFILTRATION TECHNOLOGY

EVALUATING WINEMAKING APPLICATIONS OF ULTRAFILTRATION TECHNOLOGY

Abstract

Ultrafiltration is a process that fractionates mixtures using semipermeable membranes, primarily on the basis of molecular weight. Depending on the nominal molecular weight cut-off (MWCO) specifications of the membrane, smaller molecules pass through the membrane into the ‘permeate’, while larger molecules are retained and concentrated in the ‘retentate’. This study investigated applications of ultrafiltra-tion technology for enhanced wine quality and profitability. The key objective was to establish to what extent ultrafiltration could be used to manage phenolic compounds (associated with astringency or bitterness) and proteins (associated with haze formation) in white wine. Nevertheless, ultrafiltration was also applied to red wine, despite the removal of anthocyanins and tannins (associated with colour and textural properties) being inherently detrimental to wine quality, so as to better characterise the chemical consequences of membrane filtration. The composition of permeate and retentate derived from pilot-scale fractionation of red and white wine using 10 and 20 kDa membranes, and different permeation rates (50, 80, 90, 95%) was investigated. The alcohol content and pH of permeate and retentate were not significantly different from that of the initial wine, but titratable acidity and macromolecules (proteins, polysaccharides and phenolic compounds, including anthocyanins for red wine) were progressively concentrated in the retentate, as a function of both membrane MWCO and the degree of permeation. Red wine permeates were stripped of much of their essential character, such that they were not considered commercially acceptable; whereas the removal of white wine phenolics demonstrated the potential for ultrafiltration to remediate oxidised or highly phenolic wines. Subsequent trials investigated the addition of retentate to (i) fermenting red grape must, (ii) dealcoholised wine, and (iii) permeate, as a potential strategies for enhancing wine colour stability, flavour intensity and/or mouthfeel properties. Whereas colour enhancements were not apparent, likely due to the inherent effects of dilution, differences in wine flavour and mouthfeel were perceived via sensory profiling using the Rate-All-That-Apply method. Findings will enable the wine industry to make informed decisions regarding the suitability of ultrafiltration technology as an innovative approach to improving wine quality and process efficiency, and therefore profitability.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Stephanie Angela1,2, David Wollan2,3, Richard Muhlack1,2, Keren Bindon4, Kerry Wilkinson1,2

1. The University of Adelaide
2. The Australian Research Council Training Centre for Innovative Wine Production
3. VAF Memstar
4. The Australian Wine Research Institute

Contact the author*

Keywords

membranes, phenolics, proteins, wine

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

Rootstock mediated responses of grapevine (Vitis vinifera L.) metabolism and physiology to combined water deficit and salinity stress in Syrah grafts

Water deficit and salinity are increasingly affecting the viticulture and wine industry. These two stresses are intimately related; understanding the physiological and metabolic responses of grapevines to water deficit, salinity and combined stress is critical for developing strategies to mitigate the nega- tive impacts of these stresses on wine grape production. These strategies can include selecting more tolerant grapevine cultivars and graft combinations, improving irrigation management, and using soil amendments to reduce the effects of salinity. For this purpose, understanding the response of grape- vine metabolism to altered water balance and salinity is of pivotal importance.

A NEW STRATEGY AND METHODOLOGY FOR THE CHARACTERIZATION OF POLYPHENOLS IN FINING PRECIPITATE

Polyphenols are secondary metabolite widely distributed in plant kingdom such as in fruits, in grapes and in wine. During the winemaking process, polyphenols are extract from the skin and seed of the berries. Fining is an important winemaking step just before bottling which has an impact on wine stabilization and clarification. Most the time, fining agent are animal or vegetal protein while some of them can be synthetic polymer like PVPP or natural origin like bentonite.

UNTARGETED METABOLOMICS ANALYSES TO IDENTIFY A NEW SWEET COMPOUND RELEASED DURING POST-FERMENTATION MACERATION OF WINE

The gustatory balance of dry wines is centered on three flavors, sourness, bitterness and sweetness. Even if certain compounds were already identified as contributing to sweetness, some taste modifications remain largely unexplained1,2. Some empirical observations combined with sensory analyzes have shown that an increase of wine sweetness occurs during post-fermentation maceration³. This step is a key stage of red winemaking during which the juice is left in contact with the marc, that contains the solid parts of the grape (seeds, skins and sometimes stems). This work aimed to identify a new taste-active compound that contributes to this gain of sweetness.

HYDROXYTYROSOL PRODUCTION BY DIFFERENT YEAST STRAINS: SACCHAROMYCES AND NON-SACCHAROMYCES AND THE RELATION WITH THE NITROGEN CONSUMPTION

Hydroxytyrosol (HT) is a phenolic compound with extensive bioactive properties. It is present in olives, olive oil and wines. Its occurrence in wines is partly due to yeast synthetise tyrosol from tyrosine by the Ehrlich pathway, which is subsequently hydroxylated to .
The aim of the present work is to study how different yeast strains can influence in the HT production and, how the different nitrogen consumption of each strain can interfere the production of bioactive compounds.

WHAT’S FUTURE FOR SANTORINI’S VITICULTURE IN THE CONTEXT OF CLIMATE CHANGE

The own-rooted vineyard of Santorini is a unique case of vineyard worldwide that is been cultivated for thousands of years. On the island’s volcanic soil, the vines are still cultivated with traditional techniques, which are adapted to the specific and extreme weather conditions that prevail on it. While climate change is a reality in the Mediterranean region, will Santorini vineyard endure its impact? The study of the traditional training systems, techniques and vine density, as well as the application of sustainable solutions (cover crops and use of kaolin etc.) revealed sustainable methods for the adaptation of the local viticulture to new climatic phenomena that tend to be more and more frequent in the region due to climate change.