IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Cell Walls Of Grape Mesocarp Possible Fining Agents For Red And White Wine

Cell Walls Of Grape Mesocarp Possible Fining Agents For Red And White Wine

Abstract

Clarification or fining of wines is a technique used in wineries to eliminate unwanted wine components, which negatively affect its quality. Clarification normally involves the addition of an adsorptive material that eliminates or reduces the presence of undesirable components. The problem is that many of the fining agents used in the industry contain allergens, such as caseinates or ovalbumin. The possibility of using plant cell wall material as finning agent has been previously studied [1,2]. Other possible fining agent could be the plant cell walls material from the pulp of the grape. This material is generated during the crushing of the grape and it presence could be a problem during the maceration stage, since it greatly reduces, by adsorption, the concentration of phenolic compounds in the wine. However, due to its great affinity for tannins, it could be used to reduce the wine astringency.The objective of this study was to analyze the ability of freeze-dried grape pulp plant cell walls to act as a clarifying agent in red wines of three different varieties: Cabernet Sauvignon, Syrah and Monastrell, and one white wine of the Airén variety. 0.5 g of the lyophilized cell walls were put in contact and mixed with 50 mL of the corresponding wine (tests in triplicate), and a contact time of 7 days was assayed, after which their chromatic characteristics and total tannin concentration were analyzed by spectrophotometry. Their anthocyanin and tannin composition were also analyzed by HPLC. The material was also tested for their ability to reduce the concentration of ochratoxin A and histamine in wines.The results showed that the freeze-dried cell walls of the grape pulp have a high capacity of retaining phenolic compounds, especially tannins, although there were differences between the varieties. The treated Cabernet Sauvignon wine showed the greatest reduction in tannin concentration after finning (23%), followed by Monastrell wine (18.3%) and Syrah wine (14.3%).A problem with most fining agents is that they not only bind to tannins, but also to anthocyanins. In this way, the freeze-dried walls of grape pulp also reduced the concentration of anthocyanins in the three red variety wines, although to a lesser extent than with tannins. In this case, there were practically no differences in anthocyanin reduction between the studied wines, Monastrell (12.3%), Syrah (11.3%) and Cabernet sauvignon (12.5%).In all the wines, the addition of this fining agent reduced the concentration of ochratoxin A by 50%. However, it was not so powerful when removing histamine, where only a reduction of 8% was achieved in Monastrell and Cabernet Sauvignon wines.In conclusion, grape pulp cell walls could be a fining agent that competes with other commercial agents currently used. In addition, this plant material is generated during the vinification, so their reuse as fining agent would contribute to a circular economy. 

References

1. Jiménez-Martínez, M. D., Gómez-Plaza, E., Molero, N., & Bautista-Ortín, A. B. (2017). Fining of red wines with pomace cell wall material: effect on wine phenolic composition. Food and Bioprocess Technology, 10(8), 1531-1539.
2. Jiménez-Martínez, M. D., Bautista-Ortín, A. B., Gil-Muñoz, R., & Gómez-Plaza, E. (2019). Fining with purified grape pomace. Effect of dose, contact time and varietal origin on the final wine phenolic composition. Food chemistry, 271, 570-576.

DOI:

Publication date: June 24, 2022

Issue: IVAS 2022

Type: Poster

Authors

Osete-Alcaraz Andrea1, Ortega-Regules Ana E.2, Pérez-Porras Paula1, Bautista-Ortín Ana Belén1, Osete-Alcaraz Lucia1 and Gómez-Plaza Encarna1

1Department of Food Science and Technology, Faculty of Veterinary Science, University of Murcia
2Department of Chemical Engineering, Food and Environmental, University of Américas Puebla

Contact the author

Keywords

Anthocyanins, Tannins, fining agent, ochratoxin A, histamine.

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Protected Designation of Origin (D.P.O.) Valdepeñas: classification and map of soils

The objective of the work described here is the elaboration of a map of the different types of vineyard soils that to guide the famers in the choice of the most productive vine rootstocks and varieties. 90 vineyard soils profiles were analysed in the entire territory of the Origen Denominations of Valdepeñas. The sampling was carried out in 2018 (June to October) by making a sampling grid, followed by photointerpretation and control in the field. The studied soils can be grouped into 9 different soil types (according to FAO 2006 classification): Leptosols, Regosols, Fluvisols, Gleysols, Cambisols, Calcisols, Luvisols and Anthrosols. A map showing the soil distribution with different type of soils has been made with the ArcGIS program. Regarding to the choice of rootstock, Calcisoles are soils with a high active limestone content, so the rootstocks used in these soils must be resistant to this parameter; Luvisols are deep soils with high clay content, so they will support vigorous rootstocks. Because the cartographic units are composed of two or more subgroups, with are associated in variable proportions, 9 different soil associations have been established; Unit 1: Leptosols, Cambisols and Luvisols (80%, 15% and 5% respectively); Unit 2: Cambisols with Regosols and Luvisols (40%, 30% and 30% respectively); Unit 3: Cambisols and Gleysols with Regosols (40%, 40% and 20% respectively); Unit 4: Regosols with Cambisols, Leptosols and Calcisols (40%, 30%, 15% and 15% respectively); Unit 5: Cambisols, Leptosols, Calcisols and Regosols (25% each of them); Unit 6: Luvisols with Cambisol and Calcisols (80%, 10% and 10% respectively); Unit 7: Luvisols and Calcisols with Cambisols (40%, 40% and 20% respectively); Unit 8: Calcisols with, Cambisols and Luvisols (80%, 10% and 10% respectively); Unit 9: Anthrosols. These study allow to elaborate the first map of vineyard soils of this Protected Designation of Origin in Castilla-La Mancha.

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.

Impact of changes in pruning practices on vine growth and yield

A gradual decline in vineyards has been observed over the past twenty years worldwide. This might be explained by the climate change, practices change or the increase of dieback diseases. To increase the longevity of vines, we studied the impact of different pruning strategies in four adult and four young vineyards located in France and Spain. In France, vineyards were planted with Cabernet franc on 3309C while Spanish trials were planted with Tempranillo grafted on 110R. Vegetative expression, yield, quality of berries and wood vessels conductivity were measured. The distribution of vegetative expression, yield and berry composition between primary and secondary vegetation were quantified. Finally, tomography was used to evaluate the implication of the treatments on sap flows.
First results show that i) the respectful pruning leads to an increase of 30 to 50% more secondary shoots than the aggressive pruning in France and between 15 and 20% in Spain, ii) there is no major effect on the yield over the first two years following the implementation of the new pruning practices, although the proportion of clusters from suckers is higher on the respectful pruning method. On young vines, the development of the trunk according to a respectful pruning leads to a loss of harvest 2 years after planting. This is due to the removal, on the future trunk, of the green suckers which carrying bunches. This operation carried out in spring rather than during winter pruning, would promote a better leaf / fruit balance when the plant comes into production, and could lead to better hydraulic conduction in the vessels of the trunk. Maintaining these trials for several years will provide more robust data to assess the impact of these practices on the vines over the long term.

Climate ethnography and wine environmental futures

Globalisation and climate change have radically transformed world wine production upsetting the established order of wine ecologies. Ecological risks and the future of traditional agricultural systems are widely debated in anthropology, but very little is understood of the particular challenges posed by climate change to viticulture which is seen by many as the canary in the coalmine of global agriculture. Moreover, wine as a globalised embedded commodity provides a particularly telling example for the study of climate change having already attracted early scientific attention. Studies of climate change in viticulture have focused primarily on the production of systematic models of adaptation and vulnerability, while the human and cultural factors, which are key to adaptation and sustainable futures, are largely missing. Climate experts have been unanimous in recognising the urgent need for a better understanding of the complex dynamics that shape how climate change is experienced and responded to by human systems. Yet this call has not yet been addressed. Climate ethnography, coined by the anthropologist Susan Crate (2011), aims to bridge this growing disjuncture between climate science and everyday life through the exploration of the social meaning of climate change. It seeks to investigate the confrontation of its social salience in different locations and under different environmental guises (Goodman 2018: 340). By understanding how wine producers make sense of the world (and the environment) and act in it, it proposes to focus on the co-production of interdisciplinary knowledge by identifying and foreshadowing problems (Goodman 2018: 342; Goodman & Marshall 2018). It seeks to offer an original, transformative and contrasted perspective to climate change scenarios by investigating human agency -individual or collective- in all its social, political and cultural diversity. An anthropological approach founded on detailed ethnographies of wine production is ideally placed to address economic, social and cultural disruptions caused by the emergence of these new environmental challenges. Indeed, the community of experts in environmental change have recently called for research that will encompass the human dimension and for more broad-based, integrated through interdisciplinarity, useful knowledge (Castree & al 2014). My paper seeks to engage with climate ethnography and discuss what it brings to the study of wine environmental futures while exploring the limitations of the anthropological environmental approach.

Geospatial trends of bioclimatic indexes in the topographically complex region of Barolo DOCG

Barolo DOCG is an economically important wine producing region in Northwest Italy. It is a small region of approximately 70 km2 gross area. The topography is very complex with steep sloped hills ranging in elevation from below 200 m to 550 m. Barolo DOCG wine is made exclusively from the Nebbiolo grape. Bioclimatic indexes are often used in viticulture to gain a better understanding of broader climate trends which can be compared temporally and geographically. These indexes are also used for identifying potential phenological timing, growing region suitability, and potential risks associated with expected climatic changes. Understanding how topography influences bioclimatic indexes can help with understanding of mesoscale climate behaviour leading to improved decision making and risk management strategies. The average monthly maximum and minimum temperatures, the Cool Night Index, the Huglin Index, and the monthly diurnal range (from July to October) were calculated using data from 45 weather stations within a 40 km radius of the Barolo DOCG growing area between the years 1996 and 2019. Linear and multiple regression models were developed using independent variables (elevation, aspect, slope) extracted from a digital elevation model to identify significant relationships. Bioclimatic indexes were then kriged with external drift using independent variables that showed significant relationships with the bioclimatic index using a 100 m resolution grid. The maximum monthly temperatures and the Huglin Index showed consistent significant negative relationships with elevation in all years. The minimum monthly temperatures showed no relationship with elevation but in some months a small but significant relationship was observed with aspect. Due to the lack of a relationship between minimum monthly temperatures and elevation compared to the significant relationship between maximum monthly temperatures and elevation, monthly diurnal range had a negative relationship with elevation.