terclim by ICS banner
IVES 9 IVES Conference Series 9 CHEMICAL DRIVERS OF POSITIVE REDUCTION IN NEW ZEALAND CHARDONNAY WINES

CHEMICAL DRIVERS OF POSITIVE REDUCTION IN NEW ZEALAND CHARDONNAY WINES

Abstract

According to winemakers, wine experts and sommeliers, aromas of wet stone, mineral, struck match and flint in white wines styles, such as those produced from Vitis vinifera L. cv. Chardonnay, are considered to be hallmarks of positive reduction.1,2 In recent years, the production of Chardonnay styles defined by aroma characteristics related to positive reduction has become more desirable among wine experts and consumers. The chemical basis of positive reduction is thought to originate from the concentration of specific volatile sulfur compounds (VSCs), including methanethiol (MeSH) imparting mineral and chalk notes,3 and benzenemethanethiol (BMT) responsible for struck match and flint.1,4 However, the role of other aroma compounds, including esters, higher alcohols, and other VSCs, and their contribution to the sensory perception of positive reduction in New Zealand (NZ) Chardonnay wines has not been fully investigated. We selected 12 commercial NZ Chardonnay wines to represent a range of styles from low to high intensities of mineral and flint. Wine aroma profiles were analysed using headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Quantitative descriptive analysis (QDA) was performed on the same wines using a trained panel. Wines varied greatly in both their chemical and sensorial characteristics. Multivariate analysis showed that there were several key VSCs found to be explanatory variables driving the perception of attributes related to positive reduction in the NZ Chardonnay wines. These results will be presented in the context of winemaking techniques that can be applied by the industry to achieve Chardonnay styles with positive reduction, if desired by the winemaker.

 

1. Tominaga, T.; Guimbertau, G.; Dubourdieu, D. Contribution of Benzenemethanethiol to Smoky Aroma of Certain Vitis Vinifera 
L. Wines. J. Agric. Food Chem. 2003, 51 (5), 1373–1376. https://doi.org/10.1021/jf020756c.
2. Malfeito-Ferreira, M. Wine Minerality and Funkiness: Blending the Two Tales of the Same Story. Fermentation 2022, 8 (12). https://doi.org/10.3390/fermentation8120745.
3. Rodrigues, H.; Sáenz-Navajas, M.-P.; Franco-Luesma, E.; Valentin, D.; Fernández-Zurbano, P.; Ferreira, V.; De La Fuente Blanco, A.; Ballester, J. Sensory and Chemical Drivers of Wine Minerality Aroma: An Application to Chablis Wines. Food Chem. 2017, 230, 553–562. https://doi.org/10.1016/j.foodchem.2017.03.036.
4. Capone, D. L.; Barker, A.; Williamson, P. O.; Francis, I. L. The Role of Potent Thiols in Chardonnay Wine Aroma. Aust. J. Grape Wine Res. 2018, 24 (1), 38–50. https://doi.org/10.1111/ajgw.12294.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Rebecca C.Deed1, Daisy Zhang¹, Jennifer R. Muhl², Mathilde Derycke²

1. School of Biological Sciences, The University of Auckland
2. School of Chemical Sciences, The University of Auckland

Contact the author*

Keywords

Chardonnay, Flint, Mineral, Volatile Sulfur Compounds

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

SHIRAZ FLAVONOID EXTRACTABILITY IMPACTED BY HIGH AND EXTREME HIGH TEMPERATURES

Climate change is leading to an increase in average temperature and in the severity and occurrence of heatwaves, and is already disrupting grapevine phenology. In Australia, with the evolution of the weather of grape growing regions that are already warm and hot, berry composition including flavonoids, for which biosynthesis depends on bunch microclimate, are expected to be impacted [1]. These compounds, such as anthocyanins and tannins, contribute substantially to grape and wine quality. The goal of this research was to determine how flavonoid extraction is impacted when bunches are exposed to high (>35 °C) and extreme high (>45 °C) temperatures during berry development and maturity.

EFFECT OF FUMARIC ACID ON SPONTANEOUS FERMENTATION IN GRAPE MUST

Malolactic fermentation (MLF)¹, the decarboxylation of L-malic acid into L-lactic acid, is performed by lactic acid bacteria (LAB). MLF has a deacidifying effect that may compromise freshness or microbiological stability in wines² and can be inhibited by fumaric acid [E297] (FA). In wine, can be added at a maximum allowable dose of 0.6 g/L³. Its inhibition with FA is being studied as an alternative strategy to minimize added doses of SO₂⁴. In addition, wine yeasts are capable of metabolizing and storing small amounts of FA and during alcoholic fermentation (AF).

A NEW SPECIFIC LINEAGE OF OENOCOCCUS OENI IN COGNAC APPELLATION WINES

Oenococcus oeni is the main lactic acid bacteria (LAB) species which conducts the malolactic fermentation (MLF) in wine. During MLF, O. oeni converts malic acid into lactic acid, which modulates wine aroma composition leading to better balanced organoleptic properties. O. oeni is a highly specialized species only detected in environments containing alcohol such as wine, cider or kombucha. Genome analysis of more than 240 strains showed that they form at least 4 main phylogenetic lineages and several sublineages, which are associated with different beverages or types of wines.

IMPACT OF ACIDIFICATION AT BOTTLING BY FUMARIC ACID ON RED WINE AFTER 2 YEARS

Global warming is responsible for a lack of organic acid in grape berries, leading to wines with higher pH and lower titrable acidity. The chemical, microbiological and organoleptic equilibriums are impacted by this change of organic acid concentration. It is common practice to acidify the wine in order to prevent these imbalances that can lead to wine defects and early spoilage. Tartaric acid (TA) is most commonly used by winemaker for wine acidification purposes. Fumaric acid (FA), which is authorized by the OIV in its member states for the inhibition of malolactic fermentation, could also be used as a potential acidification candidate since it has a better acidifying power than tartaric acid.

PHOTOCHEMICAL DEGRADATION OF TRYPTOPHAN IN MODEL WINE: IMPACT OF HEAVY METALS AND OXYGEN ON 2-AMINOACETOPHENONE FORMATION

The wine industry worldwide faces more and more challenges due to climate change, such as increased dryness in some areas, water stress, sunburn and early harvesting during hot summer temperatures¹. One of the resulting problems for the wine quality might be a higher prevalence of the untypical aging off-flavor (ATA)². A substance, which Rapp and Versini made responsible for ATA, is the 2-aminoace-tophenone (2-AAP)³. 2-AAP in wine causes a naphthalene, wet towels, wet wool, acacia flower or just a soapy note⁴.