GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Impact of red blotch disease on Cabernet Sauvignon and Merlot grape and wine composition and wine sensory attributes

Impact of red blotch disease on Cabernet Sauvignon and Merlot grape and wine composition and wine sensory attributes

Abstract

Context and purpose of the study: Grapevine Red Blotch disease (RB) is a recently discovered disease that has become a major concern for the viticulture and winemaking industry in California, USA. The causal agent, Grapevine Red Blotch Virus (GRBV) was identified in 2011 and its presence was confirmed in several states in the US, in Canada, and in Switzerland. It has been demonstrated that RB compromised the regulation of ripening by suppressing specific ripening events, altering the expression patterns of transcription factors and causing hormonal imbalances in Zinfandel. For the last 4 years, our research group have been focusing on the impact of RB on grape and wine composition and wine sensory properties. Our prior work demonstrated that RB decreases sugar accumulation and delayed color development in the berry, resulting in wines with lower ethanol and anthocyanin concentration, thus affecting sensory attributes. The aim of this study was to determine the impact of RB on grape and wine composition and sensory properties when grapes were harvested sequentially.

Material and Methods: Cabernet Sauvignon and Merlot vineyards from two traditional grape growing regions in California, Napa Valley and Paso Robles respectively were selected in the 2016 and 2017 season. Grape berries from infected (RB +) and healthy (RB -) grapevines were collected weekly from veraison to harvest. RB (+) grapevines were harvested sequentially at two-time points: (1) at the same time as healthy vines – but lower Brix, and (2) later when Brix was similar to those of the healthy grapes at harvest. Brix, pH, titratable acidity (TA), sugar loading, phenolic composition by protein precipitation assay and RP-HPLC and volatile composition by HS-SPME-GC-MS were determined on grapes. Wines were made in triplicate from healthy, RB symptomatic*, and second harvest RB symptomatic* grapes and analyzed for % EtOH v/v, volatile acidity, TA, free and bound SO2, phenolic composition by RP-HPLC and protein precipitation, and volatile composition by HS-SPME-GC-MS. Wine sensory properties were determined by descriptive analyses.

Results: Chemical analysis demonstrated that RB impacts berry composition by increasing TA and decreasing Brix, sugar loading, anthocyanins, altering phenolic composition and sensory attributes. Wines made from RB (+) grapes harvested later had higher pH than wines made from healthy and first harvested RB (+) fruit. On the other hand, wines made from second harvest grapes from symptomatic vines showed less impact of the disease, producing wines with chemical, phenolic and volatile profiles as well as sensory properties more similar to wines made from healthy fruit when compared to wines made from first harvest RB (+) fruit.

*Grapevines showing RB disease symptoms

DOI:

Publication date: March 11, 2024

Issue: GiESCO 2019

Type: Poster

Authors

Raul CAUDURO GIRARDELLO1*, Monica COOPER1, Rhonda SMITH1, Charles BRENNEMAN1, Anji PERRY2, Arran RUMBAUGH1, Hildegarde HEYMANN1 and Anita OBERHOLSTER1

1 Department of Viticulture and Enology, University of California, Davis, CA 95616-8749, USA
2 J. Lohr Vineyards and Wines, 6169 Airport Road, Paso Robles, CA 93446, USA

Contact the author

Keywords

Red Botch disease, grape composition, wine composition, phenolics, sensory

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Direct NMR evidence for the dissociation of sulfur-dioxide-bound acetaldehyde under acidic conditions: Impact on wines oxidative stability

SO2 reaction with electrophilic species present in wine, including in particular carbonyl compounds, is responsible for the reduction of its protective effect during wine aging. In the present study, direct 1H NMR profiling was used to monitor the reactivity of SO2 with acetaldehyde under wine-like oxidation conditions.

Grape pomace, an active ingredient at the intestinal level: Updated evidence

Grape pomace (GP) is a winemaking by-product particularly rich in (poly)phenols and dietary fiber, which are the main active compounds responsible for its health-promoting effects. GP-derived products have been proposed to manage cardiovascular risk factors, including endothelial dysfunction, inflammation, hypertension, hyperglycemia, and obesity. Studies on the potential impact of GP on gut health are much more recent. However, it is suggested that, to some extent, this activity of GP as a cardiometabolic health-promoting ingredient would begin in the gastrointestinal tract as GP components (i.e., (poly)phenols and fiber) undergo extensive catabolism, mainly by the action of the intestinal microbiota, that gives rise to low-molecular-weight bioactive compounds that can be absorbed and utilized by the body.

Underpinning terroir with data: rethinking the zoning paradigm

Agriculture, natural resource management and the production and sale of products such as wine are increasingly data-driven activities. Thus, the use of remote and proximal crop and soil sensors to aid management decisions is becoming commonplace and ‘Agtech’ is proliferating commercially; mapping, underpinned by geographical information systems and complex methods of spatial analysis, is widely used. Likewise, the chemical and sensory analysis of wines draws on multivariate statistics; the efficient winery intake of grapes, subsequent production of wines and their delivery to markets relies on logistics; whilst the sales and marketing of wines is increasingly driven by artificial intelligence linked to the recorded purchasing behaviour of consumers. In brief, there is data everywhere!

Opinions will vary on whether these developments are a good thing. Those concerned with the ‘mystique’ of wine, or the historical aspects of terroir and its preservation, may find them confronting. In contrast, they offer an opportunity to those interested in the biophysical elements of terroir, and efforts aimed at better understanding how these impact on vineyard performance and the sensory attributes of resultant wines. At the previous Terroir Congress, we demonstrated the potential of analytical methods used at the within-vineyard scale in the development of Precision Viticulture, in contributing to a quantitative understanding of regional terroir. For this conference, we take this approach forward with examples from contrasting locations in both the northern and southern hemispheres. We show how, by focussing on the vineyards within winegrowing regions, as opposed to all of the land within those regions, we might move towards a more robust terroir zoning than one derived from a mixture of history, thematic mapping, heuristics and the whims of marketers. Aside from providing improved understanding by underpinning terroir with data, such methods should also promote improved management of the entire wine value chain.

Chitosan elicits mono-glucosylated stilbene production and release in fed-batch fermentation of grape cells 

In the present study, the optimal conditions of grape (Vitis vinifera cv ‘Barbera’) cell cultures in batch and fed-batch bioreactor processes were studied to specifically improve the production of mono-glucosylated stilbenes.

When organic chemistry contributes to the understanding of metabolism mechanisms

Many compounds of interest in wine are difficult to analyze since they are present in very small quantities or they are unstable. The need for reliable data led scientists to develop complex method in order to overcome the analytical difficulties and provide accurate quantitative data for grape or wine characterization.