Terroir 2020 banner
IVES 9 IVES Conference Series 9 Regional impact on rootstock/scion mediated methoxypyrazine accumulation in rachis

Regional impact on rootstock/scion mediated methoxypyrazine accumulation in rachis

Abstract

Aim: To investigate the impact of Geographical Indications (GI) of South Australia on the rootstock/scion-mediated methoxypyrazine accumulation within the rachis of Shiraz and Cabernet Sauvignon. 

Methods and Results: Cabernet Sauvignon and Shiraz bunches were sampled at maturity from two South Australian GIs over the 2019 and 2020 harvest periods. From each region, a minimum of 18 bunches per rootstock/scion combination were sampled from across the vineyard and their rachis material was assessed for 3-isobutyl-2-methoxypyrazine (IBMP). Results indicated that region and rootstock choice significantly affect the concentrations of methoxypyrazines within the rachis material of both Shiraz and Cabernet Sauvignon varieties at harvest. 

Conclusion: 

This research highlights the effect of regionality on the concentration of methoxypyrazines within the rachis material of Cabernet and Shiraz vines grown on common rootstock varieties. The outcomes will conceivably inform viticulturalists and winemakers of how methoxypyrazine characteristics of Shiraz and Cabernet Sauvignon rachis are impacted by common rootstock/scion combinations permitting informed rootstock selection and assisting in production of a target wine style.

Significance and Impact of the Study: The presence of rachis material during red must fermentation can confer methoxypyrazines to the wine. The presence of methoxypyrazines, and predominately 3-isobutyl-2-methoxypyrazine (IBMP), in red wine can impact the flavour and aroma profile due to their ‘green’ and ‘earthy’ characteristics. Interestingly, this phenomenon has been shown to impact the aroma profile of Shiraz wines, a variety that has not been shown to naturally produce methoxypyrazines within the berries. Furthermore, it appears that the concentration of methoxypyrazines within the rachis is mediated by rootstock/scion combination and the region in which the vines are grown. As rootstock uptake increases across Australia in response to biological threats and abiotic stresses, an understanding of the viticultural and regional influences on rootstock/scion mediated rachis composition is essential to facilitate the production of high-quality Australian wines under increasingly challenging conditions.

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type : Video

Authors

Ross D. Sanders1,2,3, Paul K. Boss1,3, Dimitra L. Capone1,2, Catherine Kidman4, David W. Jeffery1,2*

1Australian Research Council Training Centre for Innovative Wine Production, The University of Adelaide, PMB1 Glen Osmond, SA, 5064, Australia
2School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1 Glen Osmond, SA, 5064, Australia
3CSIRO Agriculture and Food, Locked Bag 2, Glen Osmond, SA 5064, Australia
4Wynns Coonawarra Estate, 77 Memorial Drive, Coonawarra, SA 5263, Australia

Contact the author

Keywords

Shiraz, Cabernet Sauvignon, Vitis vinifera, wine aroma

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Berry maturity effects on physic and chemical characteristics of traditional sparkling wines produced from Chardonnay and Sauvignon blanc grapes.

One of the consequences of global warming is the quick berry development giving rise to a disconnection between sugar accumulation and the formation of important quality minor compounds such as phenolics and volatile compounds being a huge challenge for the oenologist [1]. Thus, this phenomenon is forcing the search on strategies for maintaining the quality of wines despite this situation. One possibility is to make an early harvest with a low sugar concentration (18ºbrix) and advanced harvest for sparkling wine (20-21ºbrix) and afterwards to combine base wines properly and carry out the second fermentation trying to compensate the lack of secondary metabolites due to the quick berry development and higher alcohol degree of the second one, not adequate itself for sparkling wine. The aim of this study was to assess the chemical and physical characteristics, mainly volatile profile, and foaming properties of sparkling wines from grapes of Chardonnay and Sauvignon blanc.

Quantifying water use diversity across grapevine rootstock-scion combinations

Vines require proper light levels, temperature, and water availability, and climate change is modifying these factors, hampering yield and quality. Despite the large diversity of rootstocks, varieties, and clones, we still lack knowledge of their combined effects and potential role in a warmer and dryer future. Therefore, we aim to characterize some of the existing diversity of rootstocks and genotypes and their interaction at the eco-physiological level, combining stomatal conductance (gs) and chlorophyll a fluorescence analysis.

NEW METHOD FOR THE QUANTIFICATION OF CONDENSED TANNINS AND OTHER WINE PHENOLIC COMPOUNDS USING THE AUTOMATED BIOSYSTEMS SPICA ANALIZER

Wine phenolic compounds are important secondary metabolites in enology due to their antioxidant and nutraceutical properties, and their role in the development of color, taste, and protection of wine from oxidation and spoilage. Tannins are valuable phenolic compounds that contribute significantly to these wine properties, especially in mouthfeel characteristics; however, tannin determination remains a significant challenge, with manual and time-consuming methods or complex methodologies. The purpose of this study is to propose a novel method for quantifying condensed tannins in finished wine products.

Energy optimization of the Charmat-Martinotti refermentation process

The european union has estimated that energy consumption for wine production is about 1,750 million kwh per year, of which 500 million kwh is attributable to italy. In recent years, Italy has emerged as the world’s leading wine producer with about 50 million hectoliters per year. About 20 percent (9.8 million hectoliters) of Italian wine is marketed after refermentation according to the Charmat-Martinotti method.

The role of mechanization in zone/terroir expression

Vineyard mechanization will be addressed in this review paper primarily as related to pruning and harvesting since these operations typically require a great deal of the total yearly labour demand (Intrieri and Poni, 1998). However, to be able to define how mechanization interacts with “terroir”, a rigorous definition of the latter term is needed.