Macrowine 2021
IVES 9 IVES Conference Series 9 Ethyl esters interact with the major wine Thaumatin Like Protein VVTL1

Ethyl esters interact with the major wine Thaumatin Like Protein VVTL1

Abstract

The interactions among aromatic compounds and proteins is an important issue for the quality of foods and beverages. In wine, the loss of flavor after vinification is associated to bentonite treatment and this effect can be the result of the removal of aroma compounds which are bound wine proteins. This phenomenon was recently demonstrated for long chain fatty acids and their ethyl esters (1). Since these latter compounds are spectroscopically silent, their association with proteins is not easy to measure. Therefore, the binding of ethyl esters to a wine protein has been analyzed by studying the modifications of the protein structure (which indicates protein-ligand interactions) by Synchrotron Radiation Circular Dichroism (SRCD) spectroscopy (2). The effects induced by the addition of ethyl esters (from hexanoate to dodecanoate) on the secondary structure and stability of a purified Thaumatin like-protein (VVTL1), the most abundant wine protein, was studied in a wine model solution (12% ethanol, 5 g/l mesotartaric acid, pH 3.2). As demonstrated by UV-photo denaturation assays (20 repeated consecutive scans in the far UV-region of protein), the secondary structure of VVTL1 was only slightly affected by the presence of the selected aroma esters, but protein stability was increased by the addiction of octanoate, decanoate and dodecanoate ethyl esters. On the contrary, in the presence of ethyl hexanoate protein stability decreases. These data were further confirmed by SRCD thermal denaturation assay. The results here reported demonstrate that the content of ordered structure and the protein photo and thermal stability of the main wine protein VVTL1 is modified by ethyl esters of different chain length, indicating the existence of a binding phenomenon. Therefore esters interactions with proteins may occur in wine and that this fact can modulate both the effect of bentonite treatments and the perception of the wine aroma.

(1) Vincenzi et al., 2015. J. Agric. Food Chem., 63, 2314 (2) Hussain R. et al., 2012. Spectroscopic Analysis: Synchrotron Radiation Circular Dichroism, in: Comprehensive Chirality, 8, Elsevier, Amsterdam, pp. 438-448.

ACKNOWLEDGMENTS We thank Diamond Light Source for access to beamline B23 (SM8034) that contributed to the results presented here. This research has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement nº 226716.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Andrea Curioni*, Diana Gazzola, Mattia Di Gaspero, Paolo Ruzza, Simone Vincenzi

*Università di Padova

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Characterization of Glycosidically Bound Aroma Compounds of País cv. grapes of different Chilean zones

País grape has been estimated to arrive to Chile almost 500 years ago, being the first strain grown in this country. Traditionally, this grape has been used to mix with other varieties, to produce poor quality wines, but today is beginning to be used in the production of high quality wines. However, very little is known about the chemical characteristics of this variety. The aroma is one of the most important quality attributes of wine. Volatile compounds of this beverage may come from the grape (varietal aromas), from the fermentation process, from the ageing. The aromatic compounds are found in the grape in two forms: as free volatile compounds and as non-volatile compounds. The last ones, are aroma precursors present mainly as glycoconjugates formed by a sugar and an aglycone…

Estimation of chemical age of red wines with the use of Fourier transform infrared spectroscopy (FT-IR) and chemometrics

The color of a red wine is one of the most important parameters of its quality, giving much information on its status, such as the grape variety used or the winemaking style. As the result of a complex equilibrium between different forms of anthocyanins and polymerization reactions which occur over the course of time, color can also serve as an indication of a wines’ age. For this purpose the “chemical age” i and ii indexes have been introduced by Somers in 1977. The chemical age index i measures the color absorbance after the addition of acetaldehyde while chemical index ii provides an indication of how much of the total red pigments are resistant to SO2 bleaching.

Dissecting the polysaccharide‐rich grape cell wall matrix during the red winemaking process, using high‐throughput and fractionation methods

Limited information is available on grape wall-derived polymeric structure/composition and how this changes during fermentation. Commercial winemaking operations use enzymes that target the polysaccharide-rich polymers of the cell walls of grape tissues to clarify musts and extract pigments during the fermentations. In this study we have assessed changes in polysaccharide composition/ turnover throughout the winemaking process by applying recently developed cell wall profiling approaches to both wine and pomace polysaccharides. The methods included gas chromatography for monosaccharide composition (GC-MS), infra-red (IR) spectroscopy and comprehensive microarray polymer profiling
(CoMPP) using cell wall probes.

The influence of soil management practices on functional traits and biodiversity of weed communities in Swiss vineyards

Green cover in vine rows provides many ecological services, but can also negatively impact the crop, depending on the weed species. The composition of a vineyard weed community is influenced by many parameters. Ensuring an evolution of the vine row flora into a desired direction is therefore very complex. A key step towards this goal is to know which factors influence the establishment of the weed community and which types of communities are best suited for vineyards. In this study, we analysed the weed communities of several vineyards in the Lake Geneva region (379 botanical surveys on 117 plots), with the aim to highlight the links between soil management practices (chemical and mechanical weeding, mowing, mulching roll) and phytosociological profiles, biodiversity and selected functional traits (growth forms, life strategies, root depth). T

Quantification of red wine phenolics using ultraviolet-visible, near and mid-infrared spectroscopy combined with chemometrics

The use of multivariate statistics to correlate chemical data to spectral information seems as a valid alternative for the quantification of red wine phenolics. The advantages of these techniques include simplicity and cost effectiveness together with the limited time of analysis required. Although many
publications on this subject are nowadays available in the literature most of them only reported feasibility
studies. In this study 400 samples from thirteen fermentations including five different cultivars plus 150
wine samples from a varying number of vintages were submitted to spectrophotometric and chromatographic phenolic analysis.