GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Climate change 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: June 19, 2020

Issue: GiESCO 2019

Type: Article

Authors

Julia GOUOT (1,2), Jason SMITH (1,3), Bruno HOLZAPFEL (1,4), Celia BARRIL (1,2)

(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 2019 | IVES Conference Series

Citation

Related articles…

Exploring the inner secrets of grapevine: a journey through plant-microbe interactions

Throughout centuries of anthropocentric breeding, plants have been selectively bred to enhance their quality traits and yield, often overlooking the importance of neglected attributes, like those involved in the interactions with beneficial microorganisms. This phenomenon led to an alteration in the distribution of photosynthetic products, shifting from defence mechanisms to growth, commonly described as ‘domestication syndrome’. Addressing the losses stemming from this condition is imperative just as unravelling the concealed communication between grapevines and beneficial microorganisms.

Monitoring gas-phase CO2 in the headspace of champagne glasses through diode laser spectrometry

During Champagne or sparkling wine tasting, gas-phase CO2 and volatile organic compounds invade the headspace above glasses [1], thus progressively modifying the chemical space perceived by the consumer. Gas-phase CO2 in excess can even cause a very unpleasant tingling sensation perturbing both ortho- and retronasal olfactory perception [2]. Monitoring as accurately as possible the level of gas-phase CO2 above glasses is therefore a challenge of importance aimed at better understanding the close relationship between the release of CO2 and a collection of various tasting parameters.

DETERMINATION OF MINERAL COMPOSITION IN CV. TERAN (VITIS VINIFERA L.) RED WINE AFFECTED BY PRE-FERMENTATIVE MASH COOLING, HEATING, SAIGNÉE TECHNIQUE AND PROLONGED POST-FERMENTATIVE MACERATIONS

This study aimed to determine mineral composition in red wine obtained from cv. Teran (Vitis vinifera L.), autochtonous Croatian grape variety. Six different vinification treatments, including the control treatment (7-day standard maceration), were performed to study the effects of: 48-hour pre-fermentative mash cooling (8 °C) followed by prolonged post-fermentative maceration of 13 days (C15), 28 days (C30), and saignée technique (juice runoff) proceeded with prolonged post-fermentative maceration of 13 days (CS15); and effect of 48-hour heating (50 °C) followed by prolonged post-fermentative maceration of 13 days (H15) and 28 days (H30) on macro- and microelements in wine.

Regionality in Australian Shiraz: Sensory profiles of wines from six regions and their associations with chemical, geographical and climatic elements

Aim: Regional characters relating to Shiraz in Australia are not well documented. This study aimed to characterize the sensory, chemical and climate profiles of wines from various Australian Shiraz producing regions. 

Différenciation mésoclimatique des terroirs alsaciens et relation avec les paramètres du milieu naturel

The influence of climatic conditions on the development of the vine and on the quality of the wines no longer needs to be demonstrated at the scale of the vineyard, by the regional climatic characteristics, determining on this scale the viticultural potentialities (Huglin, 1978; Branas, 1946; Riou et al ., 1994); but also on a local scale, at the level of the basic terroir unit (Morlat, 1989), by the landscape differentiation of the natural environment inducing climatic variability within the same vineyard, and partly explaining differences in functioning of the vine, in connection with the processes of maturation and the quality of the wine (Becker, 1977 and 1984; Morlat, 1989 and Lebon, 1993a). According to these authors, the climatic diversity in a wine region constitutes in addition to the edaphic component, an important component of characterization of the Basic Terroir Units (UTB).