Macrowine 2021
IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 The effects of canopy side on the chemical composition of merlot, Cabernet-Sauvignon, and Carmenère (Vitis vinifera L.) Grapes during ripening

The effects of canopy side on the chemical composition of merlot, Cabernet-Sauvignon, and Carmenère (Vitis vinifera L.) Grapes during ripening

Abstract

AIM: Evaluating the effects of canopy side on the chemical composition of Merlot, Cabernet-Sauvignon and Carmenère fruit during ripening of a Vertical shoot positioning, VSP, trained experimental vineyard with north-south row orientation.

METHODS: Cabernet-Sauvignon, Carmenère, and Merlot grapes were harvested from a VSP trained experimental vineyard with north-south row orientation, located in the O’Higgins Region of Chile (34°20’06.9″S 70°47’54.3″W). For each cultivar, three representative rows were selected, and 200 berries were randomly collected in a 50 m span, keeping samples of both sides of the canopy separated. Samplings were carried out fortnightly from the veraison to the harvest (i.e., 0, 7, 21, 35 and 49, days post veraison). Soluble solids, titratable acidity, and pH were measured according to OIV-MA-AS313-01 and OIV-MA- AS313-15 methodologies. The content of glucose, fructose, malic acid, and tartaric acid in juices were analyzed by commercial enzymatic kits. Phenolic extracts were obtained by ultrasound maceration in a 50% ethanol-water mixture from which condensed tannins by the methylcellulose precipitation assay, total phenolics by Folin-Cioacalteu, and low molecular weight phenolics by HPLC-DAD were analyzed.

RESULTS: Contrary to some investigations, our results did not show major differences in fruit composition between the varieties and canopy side, particularly when major juice parameters such as sugars or acids were analyzed. Like so, the phenolics extracts did not show statistical differences when total phenolics or condensed tannins were compared according to canopy side but was possible to identify differences and highest phenolic amount within Cabernet-Sauvignon and Merlot compared to Carmenère; however, some of the low molecular weight phenolics significantly differ when varieties from different sides of the canopy were analyzed. For instance, catechin was significatively higher in fruit from the westside of the canopy in Cabernet-Sauvignon and Merlot, whilst east facing cluster from the three varieties had higher malvidin-3-glucoside concentration. Besides the prior, significant differences in the concentration of phenolics lengthwise the ripening, were observed for the tree varieties under study.

CONCLUSIONS:

Under the conditions of this study, only minor differences on fruit composition by varieties and canopy side were observed, particularly when it comes to low molecular weight phenolics.

DOI:

Publication date: September 2, 2021

Issue: Macrowine 2021

Type: Article

Authors

Paula A. Peña-Martínez, Liudis L. PINO María A. NAVARRO, Felipe LAURIE

Universidad de Talca, Chile.

Contact the author

Keywords

canopy side, phenolics, Cabernet-Sauvignon, Merlot, Carmenère

Citation

Related articles…

Copper contamination in vineyard soils of Bordeaux: spatial risk assessment for the replanting of vines and crops

Copper (Cu) is widely and historically used in viticulture as a fungicide against mildew. Cu has a strong affinity for soil organic matter and accumulates in topsoil horizons. Thus, Cu may negatively affect soil organisms and plants, consequently reducing soil fertility and productivity. The Bordeaux vineyards have the largest vineyard surfaces (26%) within French controlled appellation and a great proportion of French wine production (around 5 million hl per year). Considering the local context of vineyard surfaces decreasing (vine uprooting) and possible new crop plantation, the issue of Cu potential toxicity rises. Therefore, the aims of this work are firstly to evaluate the Cu contamination in vineyard soils of Bordeaux, secondly to produce a risk assessment map for new vine or crop plantation. We used soil analyses from several local studies to build a database with 4496 soil horizon samples. The database was enhanced by means of pedotransfer functions in order to estimate the bioaccessible (EDTA-extractable) Cu in soils of samples without measurements. From this database, 1797 georeferenced samples with CuEDTA concentrations in the topsoil (0-50 cm depth) were used for kriging interpolation in order to produce the spatial distribution map of CuEDTA in vineyard soils. Then, the spatial distribution of Cu was crossed with vine uprooting surfaces and municipality boundaries. CuEDTAconcentrations ranged from 0.52 to 459 mg/kg and showed clear anomalies. Our results from spatial analysis showed that almost 50% of vineyard soil surfaces have CuEDTA concentrations higher than 30 mg/kg (moderate risk for new plantation) and 20% with concentrations higher than 50 mg/kg (high risk for new plantation). A decision-support map based on municipalities was realised to provide a simple tool to stakeholders concerned by land use management.

Spatial determination of areas in the Western Balkans region favorable for organic production

In problematic conditions for production of grapes and wine caused by the COVID-19 pandemic and the resulting occurrence of wine surpluses, producers are increasingly turning to the innovative viticulture and winemaking of products that are more appealing to the market and the consumers. On the other hand, consumption of the food safety or organic products, and therefore of organic grapes and wine, is increasingly common in the world, in particular in Europe. The Regional Rural Development Standing Working Group (SWG RRD), as a regional intergovernmental organization gathers actors in the viticulture and winemaking sector from states and territories of the Western Balkans (South-East Europe) in the Expert Working Group for Wine, with the aim of improving viticulture and winemaking in this region through joint activities. In accordance with the aforementioned, the SWG RRD is working on advancing organic production of grapes and wine, and on recognition of specificities of the terroir of wine-growing areas in Western Balkans. In addition, as part of the project “Facilitation of Exchange and Advice on Wine Regulations in Western Balkan Countries” helmed by the German Federal Ministry of Food and Agriculture, in addition to harmonization of relevant legislation with EU regulations, efforts are being invested towards recognition of organic wines. Within activities and project implemented by this organization, expert analyses and scientific research of the terroir of Western Balkans were carried out, and some of the results are presented in this paper.

Combining effect of leaf removal and natural shading on grape ripening under two irrigation strategies in Manto negro (Vitis vinifera L.)

The increasingly frequent heat waves during grape ripening pose challenges for high quality wine grape production. Defoliation is a common practice that can improve the control of diseases in bunches, but also it increases the exposure to sunlight. Grapes exposed to solar radiation reach temperatures over the optimum for berry development and maturation. This makes the development of irrigation and canopy management techniques of great importance to maximize yield and grape quality. A field experiment was carried out during 2021 using Manto negro wine grapes to study the effect of applied irrigation and different light exposure levels on grape quality. Two irrigation treatments were imposed based on the frequency and amount of water doses in a four-block experimental vineyard at Bodega Ribas (Mallorca). Three light exposure treatments were randomly applied in each irrigation plot. The light treatments included exposed clusters from pea size, non-exposed clusters, and shaded clusters after softening. Leaf area index and canopy porosity was estimated every 2 weeks. Midday leaf water potential was measured weekly. Additionally, apparent electrical conductivity was measured between rows to estimate the soil water content variability. Light and temperature sensors were installed at the bunch level to quantify the differences in bunch temperature and light intensity among treatments. The effect of irrigation and cluster light exposure on berry weight, TSS, TA, malic acid, tartaric acid, K+, and pH were analysed at 5 moments along grape ripening. During different heat waves, the natural shading technique decreased the maximum bunch temperature around 10 °C respect to the exposed bunches in both irrigation strategies. The combination of defoliation and shading techniques after softening decreased TSS at harvest and affected most of the quality parameters during the last stages of ripening, showing an interesting technique to delay ripening in warm viticulture areas.

Analysis of Cabernet Sauvignon and Aglianico winegrape (V. vinifera L.) responses to different pedo-climatic environments in southern Italy

Water deficit is one of the most important effects of climate change able to affect agricultural sectors. In general, it determines a reduction in biomass production, and for some plants, as in the case of grapevine, it can endorse fruit quality. The monitoring and management of plant water stress in the vineyard

Impact of yeast derivatives to increase the phenolic maturity and aroma intensity of wine

Using viticultural and enological techniques to increase aromatics in white wine is a prized yet challenging technique for commercial wine producers. Equally difficult are challenges encountered in hastening phenolic maturity and thereby increasing color intensity in red wines. The ability to alter organoleptic and visual properties of wines plays a decisive role in vintages in which grapes are not able to reach full maturity, which is seen increasingly more often as a result of climate change. A new, yeast-based product on the viticultural market may give the opportunity to increase sensory properties of finished wines. Manufacturer packaging claims these yeast derivatives intensify wine aromas of white grape varieties, as well as improve phenolic ripeness of red varieties, but the effects of this application have been little researched until now. The current study applied the yeast derivative, according to the manufacture’s instructions, to the leaves of both neutral and aromatic white wine varieties, as well as on structured red wine varieties. Chemical parameters and volatile aromatics were analyzed in grape musts and finished wines, and all wines were subjected to sensory analysis by a tasting panel. Collective results of all analyses showed that the application of the yeast derivative in the vineyard showed no effect across all varieties examined, and did not intensify white wine aromatics, nor improve phenolic ripeness and color intensity in red wine.