Macrowine 2021
IVES 9 IVES Conference Series 9 Sustainable wine industry challenge: optimised cork powder us new sustainable fining agent to remove negative volatile phenols

Sustainable wine industry challenge: optimised cork powder us new sustainable fining agent to remove negative volatile phenols

Abstract

AIM: Cork, the bark of Quercus suber L. is a natural, renewable, sustainable, and biodegradable raw material, representing an abundant and cheap source of raw material. Portugal is the major cork producer (185,000 tons) processing about three-quarters of the world’s cork, generating up to 25 wt % of cork dust as a by-product. Pre-treatments to improve cork powder biosorption performance have been studied, such as washing with solvents, soaking in salt, acid, or basic solutions, chemical oxidation, and thermal treatment. In the last decades, millions of litters of red wine have become contaminated with the yeast Dekkera/Brettanomyces acquiring an unpleasant off-flavour, named “Brett character”. This work aims to explore the use of the abundant cork powder waste, either in its natural form or after its optimisation by simple physical and chemical treatments, trying to get a new cheap and sustainable wine fining agent for removing negative volatile phenols from red wine.

METHODS: A simple process was developed to increase the performance of the natural cork powder (CKN). CKN was treated to remove the dichloromethane and ethanol extractives (9.9% of dichloromethane-ethanol extractives, CKF). CKF was sieved to obtain a particle size below 75 μm (29% of the CKF, CKF75).

RESULTS: Cork adsorptive performance improvement by removal of cork extractives, air removal, and ethanol impregnation allowed us to obtain 41% to 62% of 4-ethylphenol (4-EP) and 50% to 53% of 4-ethylguaiacol (4-EG) removal from red wine. Optimised cork powder recovers significantly the positive fruity and floral sensory of red wine.

 

CONCLUSIONS:

By simple treatments the cork powder increased significantly its performance in the negative volatile phenols removing, presenting better performance than activate carbons or chitosan. The wine treated with optimised cork powder recovers significantly its sensorial quality.

DOI:

Publication date: September 10, 2021

Issue: Macrowine 2021

Type: Article

Authors

L. Filipe-Ribeiro 

Chemistry Research Centre – Vila Real (CQ-VR), Food and Wine Chemistry Lab, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal.,Fernanda Cosme,  Chemistry Research Centre – Vila Real (CQ-VR), Food and Wine Chemistry Lab, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal. Fernando Nunes,  Chemistry Research Centre – Vila Real (CQ-VR), Food and Wine Chemistry Lab, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal.

Contact the author

mailto:

Keywords

volatile phenols, removing, optimised cork powder

Citation

Related articles…

Towards a regional mapping of vine water status based on crowdsourcing observations

Monitoring vine water status is a major challenge for vineyard management because it influences both yield and harvest quality. It is also a challenge at the territorial scale for identifying periods of high water restriction or zones regularly impacted by water stress. This information is of major importance for defining collective strategies, anticipating harvest logistic or applying for irrigation authorisation. At this spatial scale, existing tools and methods for monitoring vine water status are few and often require strong assumptions (e.g. water balance model). This paper proposes to consider a collaborative collection of observations by winegrowers and wine industry stakeholders (crowdsourcing) as an interesting alternative. Indeed, it allows the collection of a large number of field observations while pooling the collection effort. However, the feasibility of such a project and its interest in monitoring vine water status at regional scale has never been tested.

The objective of this article is to explore the possibility of making a regional map of vine water status based on crowdsourcing observations. It is based on the study of the free mobile application ApeX-Vigne, which allows the collection of observations about vine shoot growth. This information is easy to collect and can be considered, under certain conditions, as a proxy for vine water status. This article presents the first results obtained from the nearly 18,000 observations collected by winegrowers and wine industry stakeholders during 2019, 2020 and 2021 seasons. It presents the vine shoot growth maps obtained at regional scale and their evolution over the three vintages studied. It also proposes an analysis of the factors that favoured the number of observations collected and those that favoured their quality. These results open up new perspectives for monitoring vine water status at a regional scale but above they provide references for other crowdsourcing projects in viticulture.

Grape must quality and mesoclimatic variability in Fruška Gora wine-growing region, Serbia

The Fruška Gora mountain is a traditional wine-growing region in Serbia situated in the Pannonian Basin. Due to such a position, the vicinity of the Danube River and the presence of concave configuration, it is suitable for grape production. This paper provides analyses of spatial variations in meteorological parameters and grape juice quality within Fruška Gora wine region over three consecutive vintages (2018-2020). The examined period can be defined as warm with cool nights during September (AVG 18,9°C; GDD 1918°C; CI 12°CF) and with the presence of mesoclimatic variability. The East part of the study area was somewhat drier and hotter compared to other parts of the region. The analyses of grape must samples (190 in total) of five cultivars (Cabernet-Sauvignon, Merlot, Chardonnay, Sauvignon blanc and Grašac (Welschriesling)) commonly grown across the region (19 sites), were performed using Fourier Transform Infrared Technology (FTIR). Among all cultivars, Sauvignon blanc was harvested first in the East area (DOY=246±5, GDD at harvest=1552±74, 22.2±0.7 °Brix), while the latest harvest was recorded for Cabernet-Sauvignon in the West (DOY=283±5, GDD at harvest=1936±187, 23.4±1.0 °Brix ). Both the red and white cultivars had higher acidity and YAN in the grape must if the vines were grown in the North and East compared to South and West areas. According to PCA analysis, Grašac showed the lowest variation in grape must chemical composition. Thus, the results confirm that Grašac is the most stable cultivar in Fruška Gora. All monitored cultivars reached technological fruit ripeness by the end of the growing season. However, it was difficult to reach full ripeness of red cultivars, mostly beacuse of uncoupling of technolocical and phenolic ripeness. Thus, Cabernet-Sauvignon had higher variations in GDD sums at harvest compared to other cultivars, which probably increased variations in grape must quality.

Aromatic maturity is a cornerstone of terroir expression in red wine

Harvesting grapes at adequate maturity is key to the production of high-quality red wines. Enologists and wine makers define several types of maturity, including technical maturity, phenolic maturity and aromatic maturity. Technical maturity and phenolic maturity are relatively well documented in the scientific literature, while articles on aromatic maturity are scarcer. This is surprising, because aromatic maturity is, without a doubt, the most important of the three in determining wine quality and typicity (including terroir expression). Optimal terroir expression can be obtained when the different types of maturity are reached at the same time, or within a short time frame. This is more likely to occur when the ripening takes place under mild temperatures, neither too cool, nor too hot. Aromatic expression in wine can be driven, from low to high maturity, by green, herbal, fresh fruit, ripe fruit, jammy fruit, candied fruit or cooked fruit aromas. Green and cooked fruit aromas are not desirable in red wines, while the levels of other aromatic compounds contribute to the typicity of the wine in relation to its origin. Wines produced in cool climates, or on cool soils in temperate climates, are likely to express herbal or fresh fruit aromas; while wines produced under warm climates, or on warm soils in temperate climates, may express ripe fruit, jammy fruit or candied fruit aromas. Growers can optimize terroir expression through their choice of grapevine variety. Early ripening varieties perform better in cool climates and late ripening varieties in warm climates. Additionally, maturity can be advanced or delayed by different canopy management practices or training systems.

Local adaptation tools to ensure the viticultural sustainability in a changing climate

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.