Macrowine 2021
IVES 9 IVES Conference Series 9 Modulating role of SO2 in white wine protein haze formation

Modulating role of SO2 in white wine protein haze formation

Abstract

Despite the extensive research performed during the last decades, the multifactorial mechanism responsible for the white wine protein haze formation is not fully characterized. Herein, a new model is proposed, which is based on the experimental identification of sulfur dioxide as a major modulating factor inducing wine protein haze upon heating. As opposed to other reducing agents, such as 2-mercaptoethanol, dithiothreitol and tris(2-carboxyethyl)phosphine hydrochloride (TCEP), the addition of SO2 to must/wine upon heating cleaves intraprotein disulfide bonds, hinders thiol-disulfide exchange during protein interactions and can lead to the formation of novel inter/intraprotein disulfide bonds. Those are eventually responsible for wine protein aggregation which follows a nucleation-growth kinetic model as shown by dynamic light scattering [1]. Protein aggregates were further studied following heat stress to induce aggregation. We were able to dissolve the aggregates in buffer A (8 M urea, 200 mM NaCl and 30 mM sodium citrate pH 3) and B (4 % SDS, 200 mM NaCl and sodium citrate pH 3). Size-exclusion chromatography (SEC) of the dissolved proteins aggregates allowed the characterization of the different species present in solution under reducing and non-reducing conditions. Determination of free sulfhydryl groups present in native and stressed protein was also performed using 5,5ʹ-dithiobis(2-nitrobenzoic acid) (DTNB). We suggest/demonstrate that protein aggregation due to SO2 modulation under wine model solution occurs as a result of the combination between both hydrophobic interactions and the formation of new interprotein disulfide bonds. DTNB assay revealed that there were no free sulfhydryl groups both in native, heat stressed and heat stressed in the presence of SO2. Future work will focus on the study of the different protein aggregate species and on new methods for wine protein stabilization.

[1] Chagas, R., Ferreira, L. M., Laia, C. A., Monteiro, S. & Ferreira, R. B. (2016). The challenging SO2-mediated chemical build-up of protein aggregates in wines. Food Chemistry, 192, 460-469.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Ricardo Chagas*, César Laia, Luísa Carvalho, Ricardo Ferreira, Sara Monteiro

*FCT/UNL

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Characterization of non-Saccharomyces yeast and its interaction with Saccharomyces cerevisiae with investigation of fermentation kinetics and aromatic composition

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.20.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...
Read More

Use of computational modelling for selecting adsorbents for improved fining of wine

The occurrence of faults and taints in wine, such as those caused by microbial spoilage or various taints, have resulted in significant financial losses to wine producers. The wine industry commits significant financial resources towards fining and taint removal processes each year. Fining involves the addition of one or more adsorptive substrates to juice or wine to bind certain components, thus reducing their concentration [1]. However, these processes are often not selective and can also remove desirable flavour and aroma compounds.

Read More

Development of a new sustainable filtering media for wine and beer clarification and sterilisation

Different separation techniques are frequently used during vinification process. Nowadays, clarification and microbiological stabilization of wine or beer can be done using precoat filters or crossflow filters to remove yeast and bacteria. Kieselguhr powders are the most used filter aids for precoat filtration. Their crystalline structure and their pulverulent nature induce ecotoxicological risks when used. Moreover, regeneration and reuse of these filter aids is not efficient and the filtration waste requires cost effective retreatment.

Read More

How small amounts of oxygen introduced during bottling and storage can influence the metabolic fingerprint and SO2 content of white wines

The impact of minute amounts of headspace oxygen on the post-bottling development of wine is generally considered to be very important, since oxygen, packaging and storage conditions can either damage or improve wine quality. This is reflected in the generalised use of inert bottling lines, where the headspace between the white wine and the stopper is filled with an inert gas. This experiment aimed to address some open questions about the chemistry of the interaction between wine and oxygen, crucial for decisions regarding optimal closure. While it is known that similar amounts of oxygen affect different wines to a variable extent, our knowledge of chemistry is not sufficient to construct a predictive method.

Read More

IBMP-Polypenol interactions: Impact on volatility and sensory perception in model wine solution

3-Isobutyl-2-methoxypyrazine (IBMP) is one of the key molecules in wine aroma with a bell pepper aroma and a very low threshold in wine, 1-6 ng/L for white wine and 10-16 ng/L in red wine1. The differences in these thresholds are likely due to IBMP-non volatile matrix interactions. It has indeed been shown that polyphenols may influence the volatility of flavor compounds2. In the present study, we focus on IBMP-polyphenols interactions in relation to volatility and sensory perception in model wine solution. Methods: 1. GC-MS Static Headspace Analysis: Samples were analyzed by Static headspace analysis with an Agilent 7890A gas chromatograph coupled to HP 5975C mass spectrometry detector (Agilent Technologies, Santa Clara, CA, USA).

Read More