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…

Novel contribution to the study of mouth-feel properties in wines

In general, there is a well-established lexicon related to wine aroma and taste properties; however mouth-feel-related vocabulary usually includes heterogeneous, multimodal and personalized terms. Gawel et al.
(2000) published a wheel related to mouthfeel properties of red wine. However, its use in scientific publications has been limited. The authors accepted that the approach had certain limitations as it included redundant and terms with hedonic tone and some others were absent. It is of high interest to generate a mouth-feel lexicon and finding the chemical compound or group of compounds responsible for such properties in red wine. In the present work a chemical fractionation method has been developed.

Impact of some agronomic practices on grape skins anthocyanin content

Wine colour is the first quality characteristic to be assessed, especially regarding red wines. Anthocyanins are very well known to be the main responsible compounds for red wine colour. Red cultivars can synthesize and accumulate anthocyanins in berry skin to express their colour. However, anthocyanin accumulation is often influenced by a series of factors, such as genetic regulation, phytohormones, environmental conditions and viticultural management.

Evaluation of Polarized Projective Mapping as a possible tool for attributing South African Chenin blanc dry wine styles

Multiple Factor Analysis (MFA) According to the Chenin blanc Association of South Africa, there are three recognized dry wine styles, Fresh and Fruity (FF), Rich and Ripe Unwooded (RRU), and Rich and Ripe Wooded (RRW), classically attributed with the help of sensory evaluation. One of the “rapid methods” has drawn our attention for the purpose of simplifying and making style attribution for large sample sets, evaluated during different sessions, more robust. Polarized Projective Mapping (PPM) is a hybrid of Projective Mapping (PM) and Polarised Sensory Positioning (PSP). It is a reference-based method in which poles
(references) are used for the evaluation of similarities and dissimilarities between samples.

Metabolomics of grape polyphenols as a consequence of post-harvest drying: on-plant dehydration vs warehouse withering

A method of suspect screening analysis to study grape metabolomics, was developed [1]. By performing ultra-high performance liquid chromatography (UHPLC) – high-resolution mass spectrometry (HRMS) analysis of the grape extract, averaging 320-450 putative grape compounds are identified which include mainly polyphenols. Identification of metabolites is performed by a new HRMS-database of putative grape and wine compounds expressly constructed (GrapeMetabolomics) which currently includes around 1,100 entries.

Spontaneous fermentation dynamics of indigenous yeast populations and their effect on the sensory properties of Riesling

Varietal Riesling aroma relies strongly on the formation and liberation of bound aroma compounds. Floral monoterpenes, green C6-alcohols, fruity C13-norisoprenoids and spicy volatile phenols are predominantly bound to disaccharides, which are produced and stored in the grape berry during berry maturation. Grape processing aims to extract maximum amount of the precursors from the berry skin to increase the potential for a strong varietal aroma in the wine. Subsequent yeast selection plays an important part in this process.