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…

The legal concept of “cultural heritage” to refurbish the wine sector’s priorities

Following the latest oiv global report (april 26, 2024), the prevailing perception of wine consumption finds itself undergoing one of its most challenging adjustments. It’s plausible to anticipate a shift in the scope of pdo wines towards more human-centered products (wells and stiefel, 2019), necessitating the entire sector to adapt strategies to public interest patterns (touzeau, 2010: 17-31). Previously, a dominant notion of cultural property underscored the value of wine regions; the primary interest revolved around estate owners and retailers, along with vigneron tales.

Evaluation of Polarized Projective Mapping as a possible tool for attributing South African Chenin blanc dry wine styles

Multiple Factor Analysis (MFA) According to the Chenin blanc Association of South Africa, there are three recognized dry wine styles, Fresh and Fruity (FF), Rich and Ripe Unwooded (RRU), and Rich and Ripe Wooded (RRW), classically attributed with the help of sensory evaluation. One of the “rapid methods” has drawn our attention for the purpose of simplifying and making style attribution for large sample sets, evaluated during different sessions, more robust. Polarized Projective Mapping (PPM) is a hybrid of Projective Mapping (PM) and Polarised Sensory Positioning (PSP). It is a reference-based method in which poles
(references) are used for the evaluation of similarities and dissimilarities between samples.

Distribution and sensory impact of new oak wood-derived compounds in wines

Despite the numerous research studies carried out in recent years, the study of wine aroma remains of great interest due to its complexity. Wine maturation in oak barrels is described as an important step in the production of quality wines. In fact, oak wood develops several aromatic nuances through its toasting which can be released into the wine. A great deal of work has been performed in order to identify the wood-derived volatile compounds that contribute to wine aroma (e.g., whisky-lactone, maltol, eugenol, guaiacol, vanillin).

EFFECTS OF HYDROXYTYROSOL ON THE CHEMICAL PROFILE AND SENSORY ATTRIBUTES OF A RED TUSCAN WINE

The chemical profile and sensory attributes were studied in Borrigiano IGT Toscana wine (Italy), a blend of Sangiovese 85% and Cabernet Sauvignon 15% grapes harvested in September 2020, where 2-(3,4-dihydroxyphenyl)ethanol (hydroxytyrosol, HT, [1]) was added to a 750-ml wine bottle in 3 different amounts (30, 60, 120 mg) and compared with the control (no HT addition). The study aimed to evaluate whether Polyphenol-HT1®, a high purity HT (>99%) produced by Nova Mentis using biotechnology, could be used as a supplement to sulfites and how it would impact the sensory and chemical profile of this wine [2]. Each sample was prepared in triplicate.

Climate change – variety change?

In Franconia, the northern part of Bavaria in Germany, climate change, visible in earlier bud break, advanced flowering and earlier grape maturity, leads to a decrease of traditionally cultivated early ripening aromatic white wine varieties as Mueller-Thurgau (30 % of the wine growing area) and Bacchus (12 %). With the predicted rise of temperature in all European wine regions the conditions for white wine grape varieties will decline and the grapes themselves will lose a part of their aromatic and fruity expression. Variety change towards the cultivation of later ripening white wine varieties is a very expensive and long-term process, and must be accompanied by special marketing efforts.