terclim by ICS banner
IVES 9 IVES Conference Series 9 ANTI-TRANSPIRANT MODULATION OF GRAPE RIPENING: EFFECTS ON MERLOT VINE DEVELOPMENT AND ROSÉ WINE PHENOLIC AND AROMATIC PROFILES

ANTI-TRANSPIRANT MODULATION OF GRAPE RIPENING: EFFECTS ON MERLOT VINE DEVELOPMENT AND ROSÉ WINE PHENOLIC AND AROMATIC PROFILES

Abstract

Climate changes are impacting viticultural regions throughout the world with temperature increases being most prevalent.1 These changes will not only impact the regions capable of growing grapes, but also the grapes that can be grown.2 As temperatures rise the growing degree days increase and with it the sugar accumulation within the berries and subsequent alcohol levels in wine. Consequently, viticultural practices need to be examined to decrease the levels of sugars. Anti-transpirants have been used to some degree of success, however their benefits may be linked to the varietal and style of wine produced.3 With this in mind we undertook a study of anti-transpirant application to merlot grapes to determine its effectiveness for reducing alcohol in Rosé wines.

The trial was performed in a commercial vineyard in the Hawke’s Bay region of New Zealand. The vines were two cane pruned and the vineyard was managed under conventional practices. The trial was setup as a randomized block design with five vines per block. Anti-transpirant was applied using a backpack sprayer to upper portion of the canopy to the point of run off at véraison. The berries were then harvested by hand at 18 °Brix and wine making using a standardized wine making protocol at the research winery.

The harvest dates were delayed between the treated and untreated vines. The treated wines were found to have a higher pH, lower titratable acidity, and increased total phenolics. The aroma compound analysis resulted in several significant differences that were noted in the sensory evaluation. In both vintages the control wines were found to be influenced by green, vegetal, and earthy notes while the treated wines were found to be influenced by fruit aromas. These sensory attributes were confirmed by examining the aromatic compounds by PCA. This resulted in the controls being influenced by methoxypyrazines and alcohols and a few esters, compared to treated wines which were influenced by esters and terpenoids.

In conclusion, we were able to show that the application of anti-transpirant was able to dissociate the ripening process of Merlot grapes. Its application decreased sugar production but allowed for aromatic compound production. This demonstrates the potential effectiveness for anti-transpirants to control sugar in grape production to mitigate increased temperatures. These results indicate that further research is necessary to optimize the application timing of the anti-transpirant.

 

1. Van Leeuwen, C. D.-I., A.; Dubernet, M.; Duchêne, E.; Gowdy, M.; Marguerit, E.; Pieri, P.; Parker, A.; de Rességuier, L.; Ollat, N. (2019). An Update on the Impact of Climate Change in Viticulture and Potential Adaptations. Agronomy, 9, 514
2. Parker, A. K., García de Cortázar-Atauri, I., Gény, L., Spring, J.-L., Destrac, A., Schultz, H., Molitor, D., Lacombe, T., Graça, A., Monamy, C., Stoll, M., Storchi, P., Trought, M. C. T., Hofmann, R. W., & van Leeuwen, C. (2020). Temperature-based grape-vine sugar ripeness modelling for a wide range of Vitis vinifera L. cultivars. Agricultural and Forest Meteorology, 285-286, 107902.
3. Di Vaio, C., Marallo, N., Di Lorenzo, R., & Pisciotta, A. (2019). Anti-Transpirant Effects on Vine Physiology, Berry and Wine Composition of cv. Aglianico (Vitis vinifera L.) Grown in South Italy. Agronomy, 9(5), 244.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Kenneth Olejar1, Petra King2, Carmo Vasconcelos3, Elise Montgomery4, Karen Ball5, Stewart Field6

1 Appalchian State University, Department of Chemistry and Fermentation Sciences, Boone, NC, USA
2 Easten Institute of Technology, Department of Viticulture and Wine, Taradale, New Zealand
3 Bragato Research Institute, Blenheim, New Zealand
4 New Zealand Institute of Skills and Technology, Department of Viticulture and Wine, Taradale, New Zealand
5 Easten Institute of Technology, Department of Viticulture and Wine, Taradale, New Zealand
6 New Zealand Institute of Skills and Technology, Department of Viticulture and Wine, Blenheim, New Zealand

Contact the author*

Keywords

dissociatedripenin, glow-alcohol wine, wine sensory, wine aroma

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

AROMA ASSESSMENT OF COMMERCIAL SFORZATO DI VALTELLINA WINES BYINSTRUMENTAL AND SENSORY METHODOLOGIES

Sforzato di Valtellina DOCG is a special dry red wine produced from partially dehydrated Nebbiolo wine-grapes growing in the Rhaetian Alps valley of Valtellina (Lombardy, Italy). Valtellina terraced vineyards are located at an altitude of 350–800 m according to ‘heroic’ viticulture on steep slopes. The harvested grape bunches are naturally dehydrated indoors, where a slow and continuous withering occurs (about 20% w/w of weight loss), until at least 1st December when the grapes reach the desired sugar content and can be processed following a normal winemaking with maceration.
Read More

WHICH IMPACT FOR PROANTHOCYANIDIC TANNINS ON RED WINE FRUITY AROMA? SENSORY AND PHYSICOCHEMICAL APPROACHES

Previous research on the fruity character of red wines highlighted the role of esters. Literature provides evidence that, besides these esters, other compounds that are not necessarily volatiles may have an important impact on the overall aroma of wine, contributing to a modulation of its global aromatic expression. The goal of this work was to assess the olfactory consequences of a mixture between esters and proanthocyanidic tannins, through sensory and physico-chemical approaches.
Sensory analysis of numerous aromatic reconstitutions, including triangular tests, detection thresholds, and sensory profiles, were conducted in order to evaluate the sensory impact of tannins on red wine esters perception.

Read More

IN DEPTH CHARACTERIZATION OF OENOLOGICAL CHARACTERISTICS OF TWO LACHANCEA THERMOTOLERANS STARTER STRAINS

Non-Saccharomyces starter cultures became increasingly popular over the years because of their potential to produce more distinctive and unique wines. The major benefit of the use of Lachancea thermotolerans as a fermentation starter is its ability to produce relevant amounts of lactic acid and reduce alcoholic strength, making it valuable for mitigating negative impacts of climate change on grapes and wine quality. Besides, like any other non-Saccharomyces yeast, L. thermotolerans can significantly affect a whole range of other physico-chemical wine parameters.

Read More

WINE FERMENTATION METABOLITES PRODUCED BY TWO TORULASPORA DELBRUECKII STRAINS ISOLATED FROM OKANAGAN VALLEY, BC, CANADA VINEYARDS

Wine aroma is influenced by various factors, from agricultural practices in the vineyard to the enological choices made by winemakers throughout the vinification process. Spontaneous fermentations have a characteristically deeper complexity of aromas when compared to fermentations that have been inoculated with Saccharomyces (S.) cerevisiae because of the diversity of microflora naturally present on grape skins. Non-Saccharomyces yeast are being extensively studied for their ability to positively contribute to wine aroma and flavour. These yeasts are known to liberate more bound volatile compounds present in grape must than S. cerevisiae through the enzymatic action of β-glucosidases and β-lyases1.

Read More

RED WINE AGING WITHOUT SO₂: WHAT IMPACT ON MICROBIAL COMMUNITY?

Nowadays, the use of food preservatives is controversial, SO2 being no exception. Microbial communities have been particularly studied during the prefermentary and fermentation stages in a context of without added SO2. However, microbial risks associated with SO2 reduction or absence, particularly during the wine aging process, have so far been little studied. The microbiological control of wine aging is a key issue for winemakers wishing to produce wines without added SO2. The aim of the present study is to evaluate the impact of different wine aging strategies according to the addition or not of SO2 on the microbiological population levels and diversity.

Read More