 IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 The effect of viticultural treatment on grape juice chemical composition

The effect of viticultural treatment on grape juice chemical composition

Abstract

AIM: Viticultural management regimes influence the soil elemental profile of a vineyard, determining the microbial community distribution, insect life, and plant biochemistry and physiology [1]. The interactions among these grapevines, pests and microbes can influence the chemical composition of grapes and, therefore, the metabolites of the wines [2,3]. The wine industry is becoming more aware of the importance that the vineyard ecosystem plays in grape and wine production; in addition, there is a growing desire to use fewer synthetic chemicals to promote natural and diverse vineyard ecosystems. This study investigates the effect of two different viticultural management approaches on grape juice composition. Key metabolites in juice samples originating from grapes subjected to different viticultural treatments (Contemporary – use of synthetic herbicides and Future – no use of synthetic herbicides) were measured prior to alcoholic fermentation.

METHODS: Key metabolites, including amino acids, C6 compounds, and thiol precursors, were quantified in this study using a combination of GC-MS and LC-MS/MS [4]. SPE was used to extract volatile C6-compounds from the juices before analysis [5,6]. Basic oenological parameters of the juice samples were also determined. Data analysis was carried out using the software R and MetaboAnalyst.

RESULTS: Twenty-wight important metabolites in New Zealand Sauvignon blanc, Pinot noir and Merlot juice samples were detected and measured. From the results, PERMANOVA factors (Variety, Vintage, Region and Treatment) were found to be significant (p-value < 0.05). Although the factor Treatment was less than the role of the intrinsic factors Variety and Vintage, it is essential to highlight that approximately 4.1% of the variation found within the data set can be attributed to the implementation of the viticultural management regimes.

CONCLUSIONS

In this study, the chemical profile of New Zealand grape juice from grapes grown under different vineyard management regimes was explored. The results confirmed that the difference in metabolite profiles between vineyard management regimes was small but detectable. This information is noteworthy and valuable for grape growers because of increasing concerns regarding the use of synthetic chemicals in agriculture and the shift towards improved sustainable horticultural practices.

ACKNOWLEDGEMENTS

The authors wish to thank the Bragato Research Institute, New Zealand Winegrowers, and the Ministry of Business, Industry, and Employment (MBIE), for funding this work.

DOI:

Publication date: September 2, 2021

Issue: Macrowine 2021

Type: Article

Authors

Jin Wang

University of Auckland, New Zealand,Bruno FEDRIZZI, University of Auckland Rebecca E. JELLEY, University of Auckland Farhana PINU, New Zealand Institute for Plant and Food Research Limited Emma SHERMAN, New Zealand Institute for Plant and Food Research Limited Damian MARTIN, New Zealand Institute for Plant and Food Research Limited Claire GROSE, New Zealand Institute for Plant and Food Research Limited

Contact the author

Keywords

grape juice, viticultural treatments, amino acids, c6 compounds, thiol precursors

Citation

An Ag+ SPE method combined with Deans’ switch heart-cutting MDGC–MS/Olfactometry approach for identifying unknown volatile thiols in wine

Wine aroma is a crucial quality criterion. A multitude of volatile compounds have been identified and correlated to the aroma attributes perceived in wine.

In line monitoring of red wine fermentations using ir spectrospcopy

There has been a shift in modern industry to implement non-destructive and non-invasive process monitoring techniques (Helmdach et al., 2013).

A NEW TOOL TO QUANTIFY COMPOUNDS POTENTIALLY INVOLVED IN THE FRUITY AROMA OF RED WINES. DEVELOPMENT AND APPLICATION TO THE STU-DY OF THE FRUITY CHARACTER OF RED WINES MADE FROM VARIOUS GRAPE VARIETIES

A wide range of olfactory descriptors ranging from fresh and jammy fruit notes to cooked and oxidized fruit notes could describe the fruity aroma of red wines [1]. The fruity character of a wine is mainly related to the grape variety selected, to the terroir and the vinification process applied for its conception. In white wines, some volatile compounds confer directly their aroma to the wine while the question of “key” compound is more complex in red wines. According to many studies performed over the past decades, some fruity ethyl esters are directly involved in the fruity perception of red wines while others, present at subthreshold concentrations, participate indirectly to the fruity expression via perceptive interactions [2].

Permanent cover cropping with reduced tillage increased resiliency of wine grape vineyards to climate change

Majority of California’s vineyards rely on supplemental irrigation to overcome abiotic stressors. In the context of climate change, increases in growing season temperatures and crop evapotranspiration pose a risk to adaptation of viticulture to climate change. Vineyard cover crops may mitigate soil erosion and preserve water resources; but there is a lack of information on how they contribute to vineyard resiliency under tillage systems. The aim of this study was to identify the optimum combination of cover crop sand tillage without adversely affecting productivity while preserving plant water status. Two experiments in two contrasting climatic regions were conducted with two cover crops, including a permanent short stature grass (P. bulbosa hybrid), barley (Hordeum spp), and resident vegetation under till vs. no-till systems in a Ruby Cabernet (V. vinifera spp.) (Fresno) and a Cabernet Sauvingon (Napa) vineyard. Results indicated that permanent grass under no-till preserved plant available water until E-L stage 17. Consequently, net carbon assimilation of the permanent grass under no-till system was enhanced compared to those with barley and resident vegetation. On the other hand, the barley under no-till system reduced grapevine net carbon assimilation during berry ripening that led to lower content of nonstructural carbohydrates in shoots at dormancy. Components of yield and berry composition including flavonoid profile at either site were not adversely affected by factors studied. Switching to a permanent cover crop under a no-till system also provided a 9% and 3% benefit in cultural practices costs in Fresno and Napa, respectively. The results of this work provides fundamental information to growers in preserving resiliency of vineyard systems in hot and warm climate regions under context of climate change.

A.O.C. taureau de Camargue

A.O.C. réservée aux viandes fraîches de bovins mâles ou femelles, nés, élevés et abattus dans une aire géographique définie (voir carte)