GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Do high temperature extremes impact berry tannin composition?

Do high temperature extremes impact berry tannin composition?

Abstract

Context and purpose of the study – Flavonoids, including flavonols, anthocyanins, and tannins, are important contributors to grape and wine quality, and their biosynthesis is strongly influenced by bunch microclimate. While the synergistic effect of light and temperature has been intensively examined on flavonoids in relation to bunch exposure, studies targeting the sole effect of high temperature have mostly focused on anthocyanins during the ripening period. With tannin biosynthesis starting around flowering, heatwaves occurring earlier in the grape growing season could be critical. Only a few papers report the impact of temperature on tannin synthesis and accumulation; to date, none have examined the effect of high temperature extremes which, in the context of climate change, relates to increases in heatwave intensity.

Material and methods – Three potted-vine experiments were conducted inside a UV-transparent glasshouse during the 2016-17 and 2018-19 seasons. Using fans blowing hot air onto individual bunches without affecting light exposure, several temperature-related parameters were tested on well-irrigated Shiraz vines. In order, these examined high day and/or night temperatures after fruit set (E-L 31, Coombes, 1995), day temperature intensities (Low: LT, High: HT and Very High: VHT) and durations (3 to 39 h) after véraison (E-L 36, ~10 °Brix), and high day temperature at two phenological stages (E-L 31 and/or E-L 36). Berries were sampled at regular intervals, peeled, ground, and skin and seed tannin composition individually analysed by LC-MS/MS after phloroglucinolysis.

Results – During Experiment 1, heat treatments were applied for three days (+8 °C) and/or three nights (+6 °C), with day maximum temperature reaching 44.8 °C and night maximum temperature reaching 32.8 °C. Berry size was immediately affected by day temperature, while skin tannin exhibited small differences with an increase in percentage of galloylation 15 days after the end of the treatment. During Experiment 2, LT, HT and VHT respectively reached a maximum of 37, 45, and 53 °C. VHT considerably impacted on berry physiology and composition, regardless of the treatment duration (12 or 30 h), leading to berry desiccation. Tannins extracted from the dried skin were significantly reduced with some flavan-3-ol subunits proportionally more degraded than others. While the effect on skin was substantial, seed tannins were only slightly affected. Night temperature at E-L 31 (Experiment 1) and day HT at E-L 36 (Experiment 2) affected other primary metabolites but not tannin composition. Experiment 3, conducted during the 2018-19 season, combined parameters for which tannin composition was affected during season 2016-17 to confirm observed trends.

DOI:

Publication date: March 11, 2024

Issue: GiESCO 2019

Type: Poster

Authors

Julia GOUOT1,2*, Jason SMITH1,3, Bruno HOLZAPFEL1,4, Celia BARRIL1,2

1 National Wine and Grape Industry Centre, Wagga Wagga, New South Wales, 2678, Australia
2 School of Agricultural and Wine Sciences, Charles Sturt University, Wagga Wagga, New South Wales, 2678, Australia
3 New South Wales Department of Primary Industries, Orange, New South Wales, 2800, Australia
4 New South Wales Department of Primary Industries, Wagga Wagga, New South Wales, 2678, Australia

Contact the author

Keywords

Berry composition, Bunch heating, Day, Heat stress, High temperature, Phenological stage, Tannins

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Teinturier grapes: Valorization as a source of high-value compounds for the Chilean food industry

The agri-food industry is constantly searching for ingredients of high functional value, healthy and of natural origin. One species of particular interest is Vitis vinifera, due to its recognized antioxidant potential. Among the grape varieties, one group possesses these antioxidant compounds not only in the skin, but also in its pulp: Teinturier. The red grape has traditionally been used for color correction purposes in winemaking, however, its high antioxidant content transforms it into a raw material of high potential for new formulations of ingredients and foods for the health and wellness market.

Delineation significance in viticultural zoning: examples in the Southern Côtes-du-Rhône

In order for a spatialized gestion of wine-producing areas, delineation of viticultural zones is needed. Viticultural zoning according to qualitative expression of varieties is a great concern

Evaluation of a biological foliar fertilization system, in the production, agronomic and quality characteristics of three wine grape varieties

Evaluation of the fertility management practices in wine grape varieties production. Wine grape represents one of the most important productions in Greece with major impact to the socioeconomic characteristics of the country. The objective of this study is to evaluate, with the support of Geospatial Technologies, the potential effects of an innovative foliar fertilizer system, which is composed of three parts: a mineral fertilizer in a micronized formulation, a biostimulant as an enhancing factor of the process and, an amino acid compound (SANOVITA concept). The study was established at a collaborative, private vineyard, in the area of Trilofos-Thessaloniki, at the region of Northern Greece.

Effect of different canopy managements on microclimate and carbon allocation in Vitis vinifera cv Chardonnay

Climate change strongly affects the wine-growing sector which increasingly requires in situ adaptation strategies aimed at preserving the sustainability of production. Investigating microclimate becomes crucial in comprehending environmental pressures on plants. The microclimatic investigation conducted in the Orvieto PDO (central Italy) allowed us to highlight the climatic dynamics occurring in the last 25 years and the frequency and intensity of abiotic stresses. Two management strategies for the canopy were identified: early defoliation (ELR) and foliar application of Basalt Flour ® (FB) compared to the ordinary management (C) of the company (bud selection and topping). The effects on plant vigour indices (LAI), resource allocation in terms of carbon stored in the above-ground organs of the vine, and the microclimate of the canopy and the berry were evaluated. In particular, microclimate was evaluated through a network of sensors connected wirelessly (Wireless Sensor Network), dedicated to collecting information on temperature and humidity in the canopy and clusters.

Seed phenolics oxidation: development of a new ripening index 

During ripening seed tannins evolve, as demonstrated by the taste and color changes. In this work we tried to develop an objective, easy and fast index, useful for winemakers. In this direction we propose two different spectrophotometric indexes, one related to the molecular structure and tannin subunits linkages, and the other related to the antioxidant properties. Especially the second one gave very interesting and unexpected results.