IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 The antioxidant properties of wine lees extracts in model wine

The antioxidant properties of wine lees extracts in model wine

Abstract

While the ethanol and tartaric acid contained in wine lees are typically recovered by distilleries, the remaining solid fraction (yeast biomass) is usually disposed of, thus negatively affecting the overall sustainability of the wine industry. Previously we demonstrated that the wine lees’ solid fraction could be submitted to a food-grade physical extraction method (autoclave, 20 min, 121°C) to yield yeast polysaccharides with proven foaming, emulsifying and wine stabilizing properties [1,2]. In this study, the autoclave extraction procedure was applied directly on lees from red winemaking. As a result, two extracts were obtained: the Total extract, namely the whole lees after autoclave containing the soluble and insoluble fractions; the Supernatant, containing only the soluble compounds released during extraction. The composition of the extracts in terms of protein, polysaccharides, glutathione, total thiols, and total polyphenol content, was determined by spectrophotometric and chromatographic analytical methods. Subsequently, the extract’s oxidative behavior was tested by dissolving them (0.5 g/L) in model wine (20% EtOH, 5 g/L tartaric acid, 5 mg/L Fe, 0.5 mg/L Cu) containing 30 mg/L free SO2 and 0.5g/L catechin. The O2 and SO2 consumption, color development (as a function of catechin degradation), and linear sweep voltammetry (LSV) behavior were investigated. The effect of the wine lees’ extracts was benchmarked against analogs extracts obtained from a lab-grown culture of the same yeast strain present in the wine lees. Samples prepared with the wine lees’ extracts showed a higher O2 and SO2 consumption rates compared to those prepared with the lab-grown yeast extracts. All extracts protected the catechin from oxidation, with the best protective action achieved by the Total wine lees extract. This extract, along with its analog from the lab-grown yeast culture, showed the greatest resistance to anodic oxidation according to LSV. The protective action on catechin displayed by all the extracts was not fully explainable by their content in antioxidant compounds as glutathione, thiols, and wine polyphenols. Interestingly, the fact that the best results were obtained using the Total extracts in which both the soluble (released polysaccharides) and insoluble (yeast cell walls) fractions were present, allowed to hypothesize that other compounds are involved in limiting the catechin oxidation. In this scenario, the candidates are the yeast membrane sterols as they possess an oxygen-consuming action, and yeast cell wall polysaccharides as they could bind to catechin thus making it unavailable for oxidation. To conclude, wine lees can be considered a novel source of yeast extract with potential oenological application also against quality-affecting oxidative reactions. If adopted on a large scale,  this wine lees valorization strategy would result in an improvement of the overall sustainability of the wine industry.

References

[1] De Iseppi, A., Marangon, M., Vincenzi, S., Lomolino, G., Curioni, A., & Divol, B. (2021). A novel approach for the valorization of wine lees as a source of compounds able to modify wine properties. LWT, 136, 110274.
[2] De Iseppi, A., Marangon, M., Lomolino, G., Crapisi, A., & Curioni, A. (2021). Red and white wine lees as a novel source of emulsifiers and foaming agents. LWT, 152, 112273.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

De IseppiAlberto1, Curioni Andrea1,2, Marangon Matteo1,2, Invincibile Diletta3, Slaghenaufi Davide3 and Ugliano Maurizio3

1Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Viale dell’Università, 16, 35020 Legnaro, Padua, Italy
2Centre for Research in Viticulture and Enology (CIRVE), University of Padova, Conegliano, Italy
3Department of Biotechnology, University of Verona, San Pietro in Cariano, Italy

Contact the author

Keywords

wine lees, wine oxidation, voltammetry, wine color, by-product valorization

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Effect of one-year cover crop and arbuscular mycorrhiza inocululation in the microbial soil community of a vineyard

The microbial composition of the soil is an important factor to consider in viticulture, since its influence on the “terroir” and on the organoleptic properties of the wine have been demonstrated. Different agronomic techniques have the potential to modify the composition and functionality of the soil microbial community. Maintaining green covers is known to increase soil microbial diversity. The direct application of inoculum of beneficial microorganisms to the soil has also been used to increase their abundance. However, the environmental conditions of each site seem to have a determining weight in the result of these practices. In this study, we compared the effect on the microbial community of a cover crop with legumes in autumn and the inoculation of grapevines with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseae in the previous spring. The study has been carried out in a vineyard in Binissalem, Mallorca, Spain. After applying the treatments, we will analyze the soil microbial communities using the data obtained from Illumina amplification of soil DNA from the 16S and ITS regions to analyze bacteria and fungi community, respectively. In addition, we will record the physicochemical characteristics of the soil at each sampling point. The result showed that agronomic management, in the short term, has less influence than soil characteristics on the composition of the soil microbiome. With these results, we can conclude that in a vineyard, agricultural techniques should focus on improving the characteristics of the soil to improve the biodiversity of the soil microbiota.

Effect of regulated deficit irrigation regime on amino acids content of Monastrell (Vitis vinifera L.) grapes

Irrigation is an important practice to influence vine quality, especially in Mediterranean regions, characterized by hot summers and severe droughts during the growing season. This study focused on deficit irrigation regime influence on amino acids composition of Monastrell grapevines under semiarid conditions (Albacete, Southeastern of Spain). In 2019, two treatments were applied: non-irrigation (NI) and regulated deficit irrigation (RDI), watered at 30% of the estimated crop evapotranspiration from fruit set to onset of veraison. Grape amino acids content was analyzed by HPLC. Berries from non-irrigated vines showed higher concentration of several amino acids, such as tryptophan (73%), arginine (70%), lysine (36%), isoleucine (27%), and leucine (21%), compared to RDI grapes. Arginine is, together with ammonium ion, the principal nitrogen source for yeasts during the alcoholic fermentation; while isoleucine, tryptophan, and leucine are precursors of fermentative volatile compounds, key compounds for wine quality. Moreover, NI treatment increased in a 14% the total amino acids content in grapes compared to RDI treatment. The reported effects might be because yield was 70% higher in RDI vines than in the NI ones and, therefore, the sink demand was increased in the irrigated vines. In addition, NI vines suffered more severe water stress and it is known that the amino acids synthesis and accumulation can be influenced by the plant response to stress. According to the results, the irrigation regime showed effect on amino acids concentration in Monastrell grapes under semiarid conditions. Grapes from non-irrigated vines showed a higher content of several amino acids relevant to the fermentative process and to the wine aroma compounds formation. It is demonstrated that the final content of nitrogen-related components in grapes is influenced by the irrigation regime. The convenience of the irrigation strategy to suggest will depend on the desired wine style and the target yield levels.

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.

Drought effect on aromatic and phenolic potential of seven recovered grapevine varieties in Castilla-La Mancha region (Spain)

The effects of climate change are seriously affecting the quality of wine grapes. High temperatures and drought cause imbalances in the chemical composition of grapes. The result is overripe grapes with low acidity and high sugar content, which produce wines with excessive alcohol content, lacking in freshness and not very aromatic. As a consequence, the search of varieties with capacity of produce quality grapes in adverse climate conditions is a good alternative to preserve the sustainability of vineyards. In this work, quality parameters of seven Vitis vinifera L. cultivars (five whites and two reds) recently recovered from extinction and grown under two different hydric regimes (rainfed and irrigated) were analyzed during the 2020 vintage. At harvest time, weight of 100 berries, must physicochemical parameters (brix degree, total acidity, malic acid, pH), and carbon and oxygen isotope ratios (δ13C, δ18O) were determined. Subsequently, varietal aroma potential index (IPAv) and total polyphenol index (TPI) were analyzed. Quality parameters, IPAv and TPI, showed significant differences between varieties and water regimes. Both red varieties, Moribel and Tinto Fragoso, stood out for their high aromatic and phenolic potential, which was higher under rainfed regime. Regarding to white varieties, Montonera del Casar and Jarrosuelto stood out in terms of varietal aroma potential. Montonera del Casar high acidity in its musts and Jarrosuelto showed the highest berry weights.

Elevational range shifts of mountain vineyards: Recent dynamics in response to a warming climate

Increasing temperatures worldwide are expected to cause a change in spatial distribution of plant species along elevational gradients and there are already observable shifts to higher elevations as a consequence of climate change for many species. Not only naturally growing plants, but also agricultural cultivations are subject to the effects of climate change, as the type of cultivation and the economic viability depends largely on the prevailing climatic conditions. A shift to higher elevations therefore represents a viable adaptation strategy to climate change, as higher elevations are characterized by lower temperatures. This is especially important in the case of viticulture because a certain wine-style can only be achieved under very specific climatic conditions. Although there are several studies investigating climatic suitability within winegrowing regions or longitudinal shifts of winegrowing areas, little is known about how fast vineyards move to higher elevations, which may represent a viable strategy for winegrowers to maintain growing conditions and thus wine-style, despite the effects of climate change. We therefore investigated the change in the spatial distribution of vineyards along an elevational gradient over the past 20 years in the mountainous wine-growing region of Alto Adige (Italy). A dataset containing information about location and planting year of more than 26000 vineyard parcels and 30 varieties was used to perform this analysis. Preliminary results suggest that there has been a shift to higher elevations for vineyards in general (from formerly 700m to currently 850 m a.s.l., with extreme sites reaching 1200 m a.s.l.), but also that this development has not been uniform across different varieties and products (i.e. vitis vinifera vs hybrid varieties and still vssparkling wines). This is important for climate change adaptation as well as for rural development. Mountain areas, especially at mid to high elevations, are often characterized by severe land abandonment which can be avoided to some degree if economically viable and sustainable land management strategies are available.