Macrowine 2021
IVES 9 IVES Conference Series 9 Kinetic investigations of the sulfite addition on flavanols

Kinetic investigations of the sulfite addition on flavanols

Abstract

Sulfonated monomeric and dimeric flavan-3-ols are recently discovered in wine and proved to have great importance in understanding wine chemistry and quality [1, 2]. Since the mechanism of their formation is still unknown, the aim of this work was to investigate the behaviour of wine monomeric and oligomeric and polymeric flavanols in the presence of SO2, through the evaluation of the kinetic parameters of the monomeric and dimeric flavanols sulfonation at the wine pH.The experimental design considered two different pH (3 and 4) and at five different temperature values (23, 30, 40, 50 and 60 oC), in order to study the reaction products obtained by SO2 addition to both monomeric (epicatechin and catechin) and dimeric flavanols (procyanidin B2 and procyanidin B3). The quantitative measurements were carried out by using a UHPLC-QTOF-MS instrument. The results demonstrated that [3]:a) the major sulfonation route that leads quickly and in good yields to monomeric 4β-sulfonated derivatives passes through the acid-catalysed depolymerisation of proanthocyanidins; b) monomeric flavanols lead with a significantly slower process to the same 4β-sulfonated products; c) kinetic data in our hands, in particular the temperature dependence of the observed rates, suggest the involvement of two completely different reaction mechanisms for the SO2 addition to dimeric and monomeric flavanol substrates; d) the direct sulfonation of epicatechin is slightly faster with respect to catechin.In conclusion, this new knowledge provides essential information in order to better understand tannin chemistry in food and predict or model the chemical/sensorial behaviour of wine or other food rich in proanthocyanidins.

DOI:

Publication date: September 10, 2021

Issue: Macrowine 2021

Type: Article

Authors

Panagiotis Arapitsas 1, Federico BONALDO 2, Fulvio MATTIVI 2, Graziano GUELLA 2

1 Fondazione Edmund Mach, San Michele all’Adige, Italy.
2 University of Trento, Trento, Italy.

Contact the author

Keywords

proanthocyanidins; tannins; sulfonation

Citation

Related articles…

Valorization of wine lees for oenological interest by eco-responsible processes

Wine lees are the second most important wine by-product in terms of quantity after grape stalk and marc. During aging on lees, it is well known that wine lees yield compounds that act as antioxydant. However the chemical nature of the compounds involved in this behavior (except polyphenols and glutathione) has not yet been totally elucidated. The scarce knowledge of wine lees composition and their potential exploitation make them a promising candidate to obtain new antioxidant products to be used in winemaking. In this study, an eco-sustainable approach to obtain lees extracts exhibiting antioxidant capacity is proposed. Such extracts could be used in a global enological strategy of sulfites level reduction.

Increasing microalgae biomass feedstock by valorizing wine gaseous and liquid residues

Global warming due to greenhouse gases (GHG) has become a serious worldwide concern. The new EU Green Deal aims t0 achieve GHG emissions reduction by at least 55% by 2030 and a climate neutral EU economy by 2050. The deal strongly encourages GHG reducing measures at local, national and European levels. The REDWine project will demonstrate the technical, economic and environmental feasibility of reducing by, at least, 31% of the CO2 eq. emissions produced in the winery industry value chain by utilizing biogenic fermentation CO2 for microalgae biomass production

First application of an original methodology created to overcome conflicts between stakeholders in an important wine-growing territory: methodology, results, and perspectives in the application of sustainability EME4.1C

Considering the previous research and activities, also, on Sustainability EME4.1C which, as widely known, considers in a harmonious chain all the factors material, immaterial, moral and spiritual related to all aspects environmental, economic, social, existential, relational, ethical, technical and “MetaEthic” indexed 4.1C

Exploring the contributions of terroir factors on berry quality of cvs. Cabernet-Sauvignon and Merlot (Vitis vinifera L.) at the Eastern Foothills of the Helan Mountains region of China

Terroir leaves its mark on the accumulation of flavours in grape berries, triggering biochemical re-actions and ultimately shaping wine styles.

Mechanization of pre-flowering leaf removal under the temperate-climate conditions of Switzerland

Grapevine leaf removal (LR) in the cluster area is typically done between fruit set and cluster closure to create an unfavorable microclimate for fungal diseases, such as Botrytis cinerea and powdery mildew. Grape growers are now turning their attention to pre-flowering LR, which has additional benefits under certain conditions. When applied before flowering, LR strongly affects fruit set and thus the number of berries per cluster. It is therefore a good yield control tool, replacing time-consuming manual cluster thinning (Poni et al. 2006). It also improves berry structure, that is, skin thickness, skin-to-pulp ratio, and berry composition (total soluble solids, titratable acidity, and polyphenols) (Palliotti et al. 2012; Komm and Moyer 2015). By exacerbating competition for assimilates between reproductive and vegetative organs, pre-flowering LR also poses some risks. Excessive yield loss at the same year’s harvest due to a too low fruit set rate is the main concern: intensive pre-flowering LR (100% of the cluster area) can induce up to 50% yield loss in potted vines (Poni et al. 2005). Other parameters, such as cool climatic conditions during flowering, also affect fruit set rate and make it difficult to predict potential yield at harvest. Repeated and overly intensive preflowering LR can have repercussions over time and induce a decline in bud fruiting and plant vigor (Risco et al. 2014).