Macrowine 2021
IVES 9 IVES Conference Series 9 Understanding sweetness of dry wines: first evidence of astilbin isomers in red wines and quantitation in a one-century range of vintages

Understanding sweetness of dry wines: first evidence of astilbin isomers in red wines and quantitation in a one-century range of vintages

Abstract

The gustatory balance of wines relies on sweetness, bitterness and sourness. In dry wines, sweetness does not result from the presence of residual sugar as in sweet wines, but is due to other non-volatile compounds. Such taste-active compounds are released during winemaking, by grapes, yeasts or oak wood and belong numerous chemical families [1]. Beyond this diversity, stereochemistry of molecules can also influence their sensory properties [2]. However, the molecular determinants associated with this taste have only been partially elucidated. Astilbin (2R, 3R) was recently reported to contribute to wine sweetness [3]. As its aglycon contains two stereogenic centers, three other stereoisomers may be present: neoisoastilbin (2S, 3R), isoastilbin (2R, 3S), and neoastilbin (2S, 3S). These compounds have already been observed in natural products, but never in wine. This work aimed at assaying their presence for the first time in wines as well as their taste properties.The isomers were synthesized from astilbin and purified by semi-preparative HPLC. Their content was assayed by developing a UHPLC-Q-Exactive quantification method. The method was applied to screen astilbin and isomers in various wines, especially in different vintages from the same estate. Sensory analysis highlighted the sweet taste of these stereoisomers whose intensity varied according to their configuration. Quantification results revealed that while young wines contained higher concentrations of astilbin than the old ones, the concentrations of the other isomers, mainly neoastilbin, were higher in the old wines, suggesting their formation over time.These results highlight the contribution of astilbin isomers in wine sweetness. More generally, this study brings new insights to understand the chemical origin of wine taste.

DOI:

Publication date: September 17, 2021

Issue: Macrowine 2021

Type: Article

Authors

Marie Le Scanff , Syntia FAYAD, Axel MARCHAL, 

Unité de recherche Œnologie, EA 4577, USC 1366 INRA, ISVV, Université de Bordeaux, F33882 Villenave d’Ornon, France 

Contact the author

Keywords

sweetness, sensory analysis, taste, isomers, wines

Citation

Related articles…

Harvest dates, climate, and viticultural region zoning in Greece

Climate is clearly one of the most important factors in the success of all agricultural systems, influencing whether a crop is suitable to a given region, largely controlling crop production and quality, and ultimately driving economic sustainability. Today many assessments of a region’s climate comes from a combination of station and spatial climate data analyses that facilitate the evaluation of the general suitability for viticulture and potential wine styles, allows for comparisons between wine regions, and offers growers a measure of assessing appropriate cultivars and sites.

Read More

Exploring grapevine water relations in the context of fruit growth at pre- and post-veraison

Climate change is increasing the frequency of water deficit in many grape-growing regions. Grapevine varieties differ in their stomatal behavior during water deficit, and their ability to regulate water potential under dry soil conditions is commonly differentiated using the concept of isohydricity. It remains unclear whether stomatal behavior, water potential regulation, and the resulting degree of isohydricity has a relationship with changes to fruit growth during water deficit. This study was conducted on four varieties (`Cabernet Franc`, `Semillon`, `Grenache`, and `Riesling`) subjected to both short-term, severe water deficit and long-term, moderate water deficit applied at both pre- and post-veraison.

Read More

How artificial intelligence (AI) is helping winegrowers to deal with adversity from climate change

Artificial intelligence (AI) for winegrowers refers to robotics, smart sensor technology, and machine learning applied to solve climate change problems. Our research group has developed novel technology based on AI in the vineyard to monitor vineyard growth using computer vision analysis (VitiCanopy App) and grape maturity based on berry cell death to predict flavor and aroma profiles of berries and final wines.

Read More

CONVOLUTIONAL NEURAL NETWORK TO PREDICT GENETIC GROUP AND SULFUR TOLERANCE OF BRETTANOMYCES BRUXELLENSIS

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.20.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...
Read More

Extraction of polyphenols from grape marc by supercritical fluid extraction (SFE) and evaluation of their ‘bioavailability’ as dietary supplements

In the winemaking process, several compounds that remain in the grape skins and seeds after the fermentation stage are bioactive-compounds (substances with potential beneficial effects on health) that can be extracted in order to recovery valuable substances with a high commercial value for the cosmetic, food (nutraceuticals) and pharmaceutical industries. The skins contain significant amounts of bioactive substances such as tannins (16-27%) and other polyphenolic compounds (2-6.5%) in particular, catechins, anthocyanins, proanthocyanins, quercetin , ellagic acid and resveratrol.

Read More