Macrowine 2021
IVES 9 IVES Conference Series 9 Shades of shading: chemical and sensory evaluation of riesling grown under various shading techniques

Shades of shading: chemical and sensory evaluation of riesling grown under various shading techniques

Abstract

AIM: Sun exposure is needed for balanced grape ripening and sugar accumulation but is also one of the main drivers for a premature Riesling ageing. The aim of this study was to evaluate the modulation of both intensity and quality of light in the vineyard on key Riesling grape and wine parameters as an adaptation strategy to changing climate. Of particular interest was the kerosene aroma caused by the C13‑norisoprenoid TDN and other compounds associated with light-induced grape compositional changes.

METHODS: Over two vintages shade cloth of three different colours was applied to Riesling vines at bunch zone in South Australia. Light measurements and incident light wavelength assessments were performed during grape ripening, and subsequent grapes and wine were analysed for key bound and free aroma compounds. After 1-year of storage, wines were analysed by Quantitative Descriptive Analysis to quantify the holistic changes of light modulation to the sensory profile.

RESULTS: Depending on colour, shade cloth was successful in modulating either the quantity and/or wavelength of light, as well as showed different response of sugar accumulation. Shading reduced TDN concentrations and kerosene aroma in wines, with very little effect on other sensory descriptors. Interestingly, while presumed C13-norisoprenoid precursor profiles were altered between shading treatments, no significant differences were observed in resulting TDN levels. 

CONCLUSIONS

This study highlights the importance of light intensity over examined light wavelength in the vineyard to manipulate TDN. Additionally, light conditions differently affected maturity with possible implications for harvest timing and climate-induced vintage compression.

DOI:

Publication date: September 13, 2021

Issue: Macrowine 2021

Type: Article

Authors

Yevgeniya Grebneva

The Australian Wine Research Institute & the Department of Microbiology and Biochemistry, Hochschule Geisenheim University,Markus, HERDERICH, The Australian Wine Research Institute, Adelaide 5064, Australia  Doris, RAUHUT, Department of Microbiology and Biochemistry, Hochschule Geisenheim University  Eleanor, BILOGREVIC, The Australian Wine Research Institute, Adelaide 5064, Australia   Josh, HIXSON, The Australian Wine Research Institute, Adelaide 5064, Australia

Contact the author

Keywords

riesling, norisoprenoid, tdn, shade cloth

Citation

Related articles…

SENSORY IMPROVEMENT OF DEALCOHOLISED WINES

Interest and willing-ness to buy alcohol-free wines by customers is increasing for several years [1]. Due to the rising relevance of dealcoholised wines it is the objective of this study to contribute to a better understanding of the flavor variation among dealcoholised wines and to explore enological measures, how to improve final quality.
First a range of commercial, alcoholfree white wines were analysed by the holistic sensory method projective mapping, including a question for hedonic acceptance. Based on the combination of a non-target-HS-SPME-GC/MS analysis with sensory analysis we obtained a clustering of the wines into three groups.

Read More

Climatic potential to produce grapes for wine-making in the tropical north region of Minas Gerais State, Brazil

The tropical north region of Minas Gerais State is one of the least developed of Brazil and viticulture could be an alternative to develop its agriculture zone. The objective of this work was to evaluate the wine grape production climatic potential of that region.

Read More

Correlation between grape and wine quality, landscape diversity, on-field biodiversity, in doc gioia del colle, italy

Analysis of aerial photos by using GIS tools and on-field surveys of flora are used to characterize territories from an agro-ecological point of view and to assess the level of diversity of given agro-ecosystems. More and more correlations between landscape characteristics, sustainability and quality of agriculture production were speculated. In last three years a study was carried out in the area of DOC “Gioia del Colle” in Apulia, South Italy, in order to characterize and investigate different vineyards and sites and find out possible interactions and correlations between the landscape diversity, the biodiversity of fields and the quality of grapes and wines.

Read More

Les paysages viticoles des régions Vale Dos Vinhedos et Monte Belo (Brésil), un lien avec l’Etrurie

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...
Read More

Berry carbon (δ13C) and nitrogen (δ15N) isotopic ratio reflects within farm terroir diffferences

ÂThe natural abundance of carbon stable isotopes has been reported to be related to water availability in grapevines quite widely. In the case of nitrogen, the natural abundance of its stable isotopes is mainly affected by the nature of the source of nitrogen (organic vs. inorganic) used by the plant, though the bibliography available for grapevine is very scarce.

Read More