GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Impact of deficit irrigation strategies on terpene concentration in Gewürztraminer grapes

Impact of deficit irrigation strategies on terpene concentration in Gewürztraminer grapes

Abstract

Context and purpose of the study – Deficit irrigation is a viticultural practice often applied to improve the phenolic composition of red grapes and wines. However, the impact of this practice on grape terpenes – key aromatics for several grapes and wines – remains largely unknown. This study investigated the impact of deficit irrigation strategies on free and glycosylated terpenes in Gewürztraminer grapes.

Material and methods – In a field study conducted in Oliver, BC, in 2016, 2017, and 2018, deficit irrigation regimes were applied to Gewürztraminer vines at different developmental stages (pre-veraison = Early Deficit, ED; post-veraison = Late Deficit, LD; throughout the season = Prolonged Deficit, PD). A well-irrigated control (CN) treatment was also established. Treatments were replicated four times accordingly to a randomized block design. The impact of deficit irrigation treatments on vine physiology and berry metabolism was characterized with eco-physiological, biochemical, and molecular analyses. Starting three weeks after fruit set, midday-leaf water potential was measured every 7-14 days and leaf gas exchanges every 14-21 days. Berry samplings were conducted every 7-14 days to assess the effect of deficit irrigation treatments on berry sugar (total soluble solid, TSS), acid (titratable acidity, TA), and terpene concentration, as well as the expression of terpene genes. Free and glycosylated terpenes were identified and quantified using a SPME-GC-MS and a LI-GC-MS, respectively. Gene expression was analyzed using a quantitative RT-PCR.

Results – Midday leaf water potential, photosynthesis, and transpiration rates were reduced by deficit irrigation. ED, LD, and PD reduced vine yield when compared to CN, but LD reduction was small and not consistent among years. Sugar levels were also reduced by deficit irrigation, particularly by LD and PD. Total free terpenes were marginally affected by deficit irrigation treatments (P = 0.065); however, the concentration of specific terpenes, such as geraniol, was significantly (P< 0.05) higher in LD than in CN berries. LD did not increase the expression of terpene genes (e.g., VviDXSs, VviHDR, VviTPSs), suggesting that the observed increase in the concentration of some free terpenes was not regulated at the transcriptional level. Total glycosylated terpenes at harvest did not change among treatments.

DOI:

Publication date: March 12, 2024

Issue: GiESCO 2019

Type: Poster

Authors

Yevgen KOVALENKO1, Ricco TINDJAU1, Simone Diego CASTELLARIN1

1 Wine Research Centre, The University of British Columbia, 2205 East Mall, Vancouver, BC, V6T0C1, Canada

Contact the author

Keywords

Aroma, Grapevine, Ripening, Water Deficit, Yield

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

IDENTIFYING POTENTIAL CHEMICAL MARKERS RESPONSIBLE FOR THE PERMISSIVENESS OF BORDEAUX RED WINES AGAINST BRETTANOMYCES BRUXELLENSIS USING UNTARGETED METABOLOMICS

All along the red winemaking process, many microorganisms develop in wine, some being beneficial and essential, others being feared spoilers. One of the most feared microbial enemy of wine all around the world is Brettanomyces bruxellensis. Indeed, in red wines, this yeast produces volatile phenols, molecules associated with a flavor described as “horse sweat”, “burnt plastic” or “leather”. To produce significant and detectable concentrations of these undesired molecules, the yeasts should first grow and become numerous enough. Even if the genetic group of the strain present and the cellar temperature may modulate the yeast growth rate¹ and thus the risk of spoilage, the main factor seems to be the wines themselves, some being much more permissive to B. bruxellensis development than others.

Chemical characterization of distinctive aroma profiles of Valpolicella and Amarone wines

Valpolicella is an Italian wine producing region, famous for the production of high-quality red wines. A distinctive characteristic of this region is the extensive use of post-harvest withering.

Prediction of sauvignon blanc quality gradings with static headspace−gas chromatography−ion mobility spectrometry (SHS−GC−IMS) and machine learning

The main goal of the current study is the development of a cost-effective and easy-to-use method suitable for use in the laboratory of commercial wineries to analyze wine aroma. Additionally, this study attempted to establish a prediction model for wine quality gradings based on their aroma, which could reveal the important aroma compounds that correlate well with different grades of perceived quality METHODS: Parameters of the SHS−GC−IMS instrument were first optimized to acquire the most desirable chromatographic resolution and signal intensities. Method stability was then exhibited by repeatability and reproducibility. Subsequently, compound identification was conducted. After method development, a total of 143 end-ferment wine samples of three different quality gradings from vintage 2020 were analyzed with the SHS−GC−IMS instrument. Six machine learning methods were employed to process the results and construct a quality prediction model. Techniques that aim to explain the model to extract useful insights were also applied.

Anthocyanins Chemistry During Red Wine Ageing

Anthocyanins are the main pigments present in young red wines, being responsible for their intense red color. These pigment in aqueous solutions occur in different forms in equilibrium that are dependent on the pH

Effects of different soil types and soil management on greenhouse gas emissions 

Soil is important in the carbon cycle and the dynamics of greenhouse gases (CO2, CH4 and N2O). Key soil characteristics, such as organic matter content, texture, structure, pH and microbial activity, play a determining role in GHG emissions[1]. The objective of the study is to delimit different types of soil, with different soil management and to be able to verify the differences in CO2, CH4 and N2O emissions. The study was carried out in a vineyard of Bodegas Campo Viejo in Logroño (La Rioja), whose plant material is Vitis vinifera L. cv. Tempranillo.