GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Changes in phenolic maturity and texture characteristics of the grape berry under pre-, and post-veraison water deficit

Changes in phenolic maturity and texture characteristics of the grape berry under pre-, and post-veraison water deficit

Abstract

Context and purpose of the study – Kékfrankos (Vitis vinifera L.) grapevines grafted on Teleki-Kober 5BB rootstock were submitted to water deficit under greenhouse conditions. The aim of the experiment was to study the effect of pre-, and post-veraison water deficit on grape berry phenolic maturity and texture characteristics.

Material and methods – Plants were planted into 50L white plastic containers in a mixture of perlite (20 %), loamy soil (30 %) and peat (50 %) (v/v). Three regimes of water supply were examined: (1) moderate water deficit from berry set until veraison (WD1), (2) moderate water deficit from veraison until harvest (WD2), (3) no water deficit (C). The water deficit treatments defined by the leaf daily stomatal conductance (between
50-150 H2O mmol m-2s-1). Anthocyanin glucosides and flavonols from berry skin were measured by Shimadzu HPLC system, berry texture characteristics were monitored by TA.XT Plus Texture Analyser. Cell and seed maturity indexes (CMI %, SMI %) and basic parameters (yield, sugar concentration, pH, must acidity) were also investigated.

Results – Pre-veraison treatment resulted in the lowest berry and cluster weight. The highest sugar concentration was found in control berries, and it was followed by the WD1 and WD2 treatments. Berries of the well-watered plants presented the lowest phenolic concentration. Pre-veraison water deficit resulted in a sllighty higher concentration of anthocyanin-glucosides compared to post-veraison water deficit. Water restriction during the ripening period induced higher flavonol (ie. quercetin, kaempferol etc.) concentration related to berry skin fresh weight as well as to the whole berry compared to WD1 treatment. Berry skin hardness (Fsk) was the highest in the case WD2 and the lowest was in WD1. Similar results were obtained in the case of berry skin thickness (Spsk). Seed (SMI %) maturity index presented higher values in the case of WD treatments compared to C. Cell maturity index (CMI %) of WD2 was significantly higher than C and WD1, however no differences were found between C and WD1.

DOI:

Publication date: June 18, 2020

Issue: GiESCO 2019

Type: Poster

Authors

Zsolt Zsófi1Ottó Bencsik2, András Szekeres2, Xénia Pálfi3, Ádám Bozó1,Szabolcs Villangó1

(1) Eszterházy Károly University, Department of Viticulture And Oenology, Leányka Str. 6, Eger H-3300 Hungary
(2) University Of Szeged, Department Of Microbiology, Közép Fasor 52., Szeged, H-6726 Hungary, 3eszterházy Károly University, Food And Wine Research Institute, Leányka Str. 6., Eger, H-3300, Hungary

Contact the author

Keywords

water deficit, anthocyanin extractability, phenolic maturity, berry texture

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Great highlands wine growing terroir: conditions and expressions

During 1982 started our wine growing project at the Puntalarga Hill, between 2500 and 2600 meters a.s.l.: 5.78 ºN, 72.98 ºW. Pinot noir, white Riesling and Riesling x Silvaner crossings are the most planted grapevines. Since 1984 research and development activities are carried out on pertinent subjects.

TCA – A status report on South African cork closures

Cork taint decreases the commercial value of wine as tainted wines are rejected by consumers. Although other compounds in wine and cork can also be responsible for causing a taint, 2,4,6-trichloroanisole (TCA) is regarded as the primary cause of cork taint. As cork taint is often used in marketing campaigns against natural cork closures,

Influence of grape withering on corvina and corvinone aroma composition

AIM:Valpolicella is a wine region located in Italy north-east, famous for the production of dry and sweet red wines from withered grapes, including Amarone and Recioto. The aim of this study is to understand the influence of the withering process on Corvina and Corvinone wines aroma profiles. METHODS:Wines were produced with a standard red wine winemaking protocol with Corvina and Corvinone grapes from different Valpolicella vineyards and vintages. In consideration of the local traditional practice of post-harvest withering of the grapes, wines from each vineyard were obtained from either fresh and withered grapes. Wines were analysed by Solid Phase Extraction and Solid Phase Micro Extraction gas chromatography coupled to mass spectrometry.

Mechanisms involved in the heating of the environment by the aerodynamic action of a wind machine to protect a vineyard against spring frost

One of the main consequences of global warming is the rise of the mean temperature. Thus, the heat summation by the plants begins sooner in the early spring, and by cumulating growing degree-days, phenological development tends to happen earlier. However, spring frost is still a recurrent phenomenon causing serious damages to buds and therefore, threatening the harvests of the winegrowers. The wind machine is a solution to protect fruit crops against spring frost that is increasingly used. It is composed of a 10-m mast with a blowing fan at its peak. By tapping into the strength of the nocturnal thermal inversion, it sweeps the crop by propelling warm air above to the ground. Thus, stratification is momentarily suppressed. Furthermore, the continuous action of the machine, alone or in synergy, or the addition of a heater allow the bud to be bathed in a warmer environment. Also, the punctual action of the tower’s warm gust reaches the bud directly at each rotation period. All these actions allow the bud to continuously warm up, but with different intensities and over a different period. Although there is evidence of the effectiveness of the wind machines, the thermal transfers involved in those mechanisms raise questions about their true nature. Field measurements based on ultrasonic anemometers and fast responding thermocouples complemented by laboratory measurements on a reduced scale model allow to characterize both the airflow produced by the wind machine and the local temperature in its vicinity. Those experiments were realized in the vineyard of Quincy, in the framework of the SICTAG project. In the future paper, we will detail the aeraulic characterization of the wind machine and the thermal effects resulting from it and we will focus on how the wind machine warms up the local atmosphere and enables to reduce the freezing risk.

Withering of the ‘Moscato giallo’ grapes under covered space

For the purpose of producing predicate wines in northern part of Croatia, grapes are traditionally left on the vine unpicked. However, grapes on the vine are exposed to unfavorable environmental conditions that affect rapid rotting and attacked by birds. To eliminate the mentioned risks, the grapes can be picked and placed in a protected space (loft, greenhouse, etc.) suitable for drying. This study presents the results of research on withering grapes of the ‘Moscato giallo’ variety in two tretment: sun drying (under covered terrace) and drying in the shade (loft). The following quality parameters were monitored: mass of grapes, sugar concentration, content of total acids, pH, content of organic acids.