terclim by ICS banner
IVES 9 IVES Conference Series 9 SHIRAZ FLAVONOID EXTRACTABILITY IMPACTED BY HIGH AND EXTREME HIGH TEMPERATURES

SHIRAZ FLAVONOID EXTRACTABILITY IMPACTED BY HIGH AND EXTREME HIGH TEMPERATURES

Abstract

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 ex-posed to high (>35 °C) and extreme high (>45 °C) temperatures during berry development and maturity. The sole effect of temperature was investigated on well-irrigated potted Shiraz grapevines grown in a glasshouse, where either the whole vine or bunches-only were heated using fans. For both experiments, berries were sampled at harvest, peeled, ground and total flavonoids were extracted using 60% acetone [2]. Two additional assays evaluated the potential temperature impact on subsequent wine composition using wine-like extraction (15% ethanol) [3] or micro-scale winemaking. Detailed tannin composition was primarily determined by LC-MS/MS after phloroglucinolysis [2], with complementary total tannin concentration (methyl cellulose precipitable assay). Secondary metabolites such as phenolic acid and anthocyanins were also analyzed.

The present work showed that short spells of high temperature may not impact on skin and seed tannin extractability when assessed on visually undamaged berries by harvest. Indeed, while total skin tannin concentrations, extracted with 60% acetone, were clearly reduced by a rise of temperature around véraison, skin extractable tannin (15% ethanol) and seed tannin concentrations were not impacted. In damaged berries at harvest, skin tannins were dramatically reduced while seed tannins were mostly preserved. Wine quality, made with a mix of heat-damaged and undamaged berries, was significantly reduced when about 20% (by mass) of the berries were visually damaged and necrotic, corresponding to about 50% of damaged berries (in number). Maintaining wine quality under a changing climate with more frequent extreme events leading to heat stress and/or water stress is challenging. However, this study showed that the impact of heatwaves in the vineyard may be compensated by a better extraction during winemaking and require further investigations at winery scales.

 

1. Gouot, J. C., Smith, J. P., Holzapfel, B. P., Walker, A. R., & Barril, C. (2019d). Grape berry flavonoids: a review of their biochemical responses to high and extreme high temperatures. Journal of Experimental Botany, 70(2), 397-423
2. Pinasseau, L., Verbaere, A., Roques, M., Meudec, E., Vallverdú-Queralt, A., Terrier, N., Boulet, J.-C., Cheynier, V., & Sommerer, N. (2016). A fast and robust UHPLC-MRM-MS method to characterize and quantify grape skin tannins after chemical depolymerization. Molecules, 21(10), 1409.
3. Bindon, K. A., Kassara, S., & Smith, P. A. (2017). Towards a model of grape tannin extraction under wine-like conditions: the role of suspended mesocarp material and anthocyanin concentration. Australian Journal of Grape and Wine Research, 23(1), 22-32 

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Julia GOUOT1,2, Jason SMITH1,4, Bruno HOLZAPFEL5, Celia BARRIL1,3

1. School of Agricultural, Environmental and Veterinary Sciences, National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia
2. Current address : Univ. Bordeaux, Bordeaux INP, INRAE, OENO, UMR 1366, ISVV, F-33140 Villenave d’Ornon, France
3. Gulbali Institute, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
4. New South Wales Department of Primary Industries, Orange, New South Wales, 2800, Australia
5. Wagga Wagga Agriculture Institute, New South Wales Department of Primary Industries, Wagga Wagga, NSW 2650, Australia

Contact the author*

Keywords

Extractability, High temperature, Flavonoids, Tannins

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

USING CHECK-ALL-THAT-APPLY (CATA) TO CATEGORIZE WINES: A DECISION-MAKING TOOL FOR WINE SELECTION

Bordeaux is the largest appellation vineyard in France. This contrasting vineyard with varied terroirs offers all styles of wine, resulting from the blending of several grape varieties. If these different profiles make the renown of Bordeaux wines, it can appear as a constraint when the aim is to study Bordeaux wines in their diversity. The selection of a representative sample can be performed by a sensory analysis carried out by trained panelists or by wine professionals, which can take several forms: consensus among experts, conventional descriptive analysis, typicality or quality evaluation. However, because of time, economic, and logistical constraints, these methods have limited applications. As an alternative to classical descriptive analysis, more intuitive methods that do not require training have been proposed recently to describe wines using an expert panel such as Napping, Free Choice or Flash Profiling, CATA or RATA.

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.

ADDITION OF OAK WOOD ALTERNATIVE PRODUCTS: QUALITATIVE AND SENSORIAL EFFECTS FOR A WHITE WINE OF ALIGOTE

Wines matured in contact with wood are extremely popular with consumers all over the world. Oak wood allows the organoleptic characteristics of wine to be modified. Wines are enriched with volatile and non-volatile compounds extracted from the wood. The aromas extracted from oak wood contribute to the construction of the wine’s aromatic profile and the main polyphenols extracted can modify taste perceptions such as astringency and bitterness. All the compounds extracted from the wood thus contribute to the balance and quality of the wines.

CLIMATE CHANGE EFFECT ON POLYPHENOLS OF GRIGNOLINO GRAPES (VITIS VINIFERA L.) IN HILLY ENVIRONMENT

Current changes of ecoclimatic indicators may cause significant variation in grapevine phenology and grape ripening. Climate change modifies several abiotic factors (e.g. temperature, sunlight radiation, water availability) during the grapevine growth cycle, having a direct impact on the phenological stages of the grapevine, modulating the metabolic profile of berries and activating the synthesis and accumulation of diverse compounds in the skin of berries, with consequences on the composition of the grapes.
The influence exerted by different meteorological conditions, during three consecutive years (2020-2022) on secondary metabolites such as the polyphenolic profile of Grignolino grapes was investigated. The samples were collected from three vineyards characterized by different microclimatic conditions mainly related to the vineyard aspect and to a different age of the plants.

ANALYZING THE ROLE OF ELEMENTAL SULFUR IN GRAPE JUICE ON THE DEVELOPMENT OF POLYFUNCTIONAL MERCAPTANS IN SAUVIGNON BLANC WINES

Sauvignon blanc is characterized by distinctive aromas, both fruity and herbaceous. The “green” character has been attributed to the methoxypyrazines, while the “fruity” character is associated with polyfunctional mercaptans . Polyfunctional mercaptans are of great significance due to their high impact on wines and associated low perception thresholds.
Elemental sulfur (S⁰) is widely used to protect grapevines from powdery mildew.