WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 1 - WAC - Oral presentations 9 Integrative grape to wine metabolite analyses to study the vineyard “memory” of wine

Integrative grape to wine metabolite analyses to study the vineyard “memory” of wine

Abstract

Wine production is a complex multi-step process and the end-product is not easily defined in terms of composition and quality due to the diversity of the raw materials (grapes) and the biological agents (yeast and bacteria) used/present during the fermentation. Furthermore, linking what happens in the vineyard to the wine fermentation and ultimately to characteristics in the wine during ageing is often attempted in scientific studies, but clear causal relationships between factors are not easy to extract. Most wine research is therefore split along viticultural or oenological experimentation. Oenologists/yeast biologists seek direct links between the yeast fermenting a specific juice and the resulting changes in the wines, whereas viticultural studies explore treatments and their effects on grape production and berry quality parameters. If these studies indeed attempt to link back to the vineyards or the wines respectively, invariably one or more of the steps in the wine system is left unexplored, or being handled as a black box. The scientific challenge and opportunity therefore remains to study wine as a system (from vineyard to tank to barrel to bottle to glass). Our approaches in this regard will be explained by using examples from model vineyards under study where grape berries and their reactions to modulated environmental factors were studied using climatic monitoring in combination with molecular and metabolite profiling of the berries during all stages of development. These characterised grapes were then fermented into wines while continuing the detailed metabolite profiling of the juice and wine matrices. The wines were also subjected to sensory evaluations to complete the analysis of the final products. With these studies, we hope to contribute to the analysis of grape and wine active compounds in a holistic manner in order to identify correlations and predict outcomes under a specific set of conditions.

DOI:

Publication date: June 9, 2022

Issue: WAC 2022

Type: Article

Authors

Melane Vivier

Presenting author

Melane Vivier – South African Grape and Wine Research Institute, Department of Viticulture and Oenology, Stellenbosch University

Contact the author

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

Polyphenols in kombucha: Metabolomic analysis of biotransformations during fermentation

Kombucha is a non-alcoholic beverage made of sugared tea that is transformed by a symbiotic consortium of yeasts and bacteria. This beverage is increasingly produced at industrial scale, but its quality standards remain to be defined. Metabolomics analysis was carried out using FT-ICR-MS to understand the chemical transformations induced by the production phases and the type of tea on

Yeast mannoprotein characterization and their effect on Oenococcus oeni and malolactic fermentation

Mannoproteins are released at the end of alcoholic fermentation due to yeast autolysis [1]. It has been described a positive effect of these molecules on lactic acid bacteria growth [2]. The main objective of this work was the characterization of different mannoproteins extracted from active dry yeast (ADY) and the assessment of their effect on Oenococcus oeni and malolactic fermentation (MLF).

Climate and the evolving mix of grape varieties in Australia’s wine regions

The purpose of this study is to examine the changing mix of winegrape varieties in Australia so as to address the question: In the light of key climate indicators and predictions of further climate change, how appropriate are the grape varieties currently planted in Australia’s wine regions? To achieve this, regions are classified into zones according to each region’s climate variables, particularly average growing season temperature (GST), leaving aside within-region variations in climates. Five different climatic classifications are reported. Using projections of GSTs for the mid- and late 21st century, the extent to which each region is projected to move from its current zone classification to a warmer one is reported. Also shown is the changing proportion of each of 21 key varieties grown in a GST zone considered to be optimal for premium winegrape production. Together these indicators strengthen earlier suggestions that the mix of varieties may be currently less than ideal in many Australian wine regions, and would become even less so in coming decades if that mix was not altered in the anticipation of climate change. That is, grape varieties in many (especially the warmest) regions will have to keep changing, or wineries will have to seek fruit from higher latitudes or elevations if they wish to retain their current mix of varieties and wine styles.

Biosurfactant from corn-milling industry improves the release of phenolic compounds during red winemaking

AIM: Biosurfactants can be used as emulsifier agents to improve the taste, flavour, and quality of food-products with minimal health hazards [1]. They are surface-active compounds with antioxidant and solubilizing properties [2].

EVOLUTION OF CHEMICAL AND SENSORIAL PROFILE OF WINES ELABORATED WITH THEIR OWN TOASTED VINE-SHOOTS AND MICRO-OXYGENATION

The positive contribution of toasted vine-shoots (SEGs, Shoot from vines – Enological – Granule) used in winemaking to the chemical and sensory profile of wines has been widely proven. However, the combination of this new enological tool with other winemaking technologies, such as micro-oxygenation (MOX), has not been studied so far. It is known that micro-oxygenation is used in wineries to stabilizes color, improves structure or combining with oak alternatives products to achieve a more effective aroma integration of wines. For that, its implementation in combination with SEGs could result in differentiated wines.