IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Effect of different pH values on the interaction between yeast mannoproteins and grape seed flavanols

Effect of different pH values on the interaction between yeast mannoproteins and grape seed flavanols

Abstract

The consequences of the global climate change in the vitiviniculture are revealed as a gap between phenolic and technological grape maturities, higher grape sugar concentration that leads to high wine alcohols levels, lower acidities and high pH values, among others. The unbalanced phenolic maturity caused in this scenario leads to harsh astringency and to instable colour of wines. Previous studies have reported that the addition of yeast mannoproteins (MPs) to wines may have positive effects on these two organoleptic properties due to their capability to interact with wine polyphenols [1]; however, studies about the effect of the pH on these interactions have not been carried out so far.

 MPs are located in the outer layer of yeast cell wall (Saccharomyces cerevisiae) and they are naturally released into the wine during alcoholic fermentation when yeast is actively growing or during aging when cell wall breaks down in the process known as autolysis. Also, commercial MPs can be added during winemaking and/or ageing. The aim of this work was to study the effect of different pH values (pH 3.0 and 4.0) on the interactions between a flavanol extract from Vitis vinifera L. Tempranillo seeds and the MPs obtained from Saccharomyces cerevisiae. Here, the isolation of MPs from the cell walls of S. cerevisiae was performed using Zymolyase 20T enzyme. MPs were purified by using ethanol, temperature and dialysis. The obtained MPs were characterized by SDS-PAGE and their molecular weights (MWs) were determined by HRSEC-RID [2]. The protein percentage was determined by the Lowry method. The monosaccharide composition was determined by HPLC-MS after derivatisation with 1-phenyl-3-methyl-5-pyrazolone (PMP) [3]. Four main MP fractions were identified: F1 (~2%), with a MW 528.8 kDa, F2 (~12%) (174.1 kDa), F3 (~61 %) (61.0 kDa) and F4 (~25 %) (<10 kDa). The MP–flavanol interactions were performed at pH=3 and pH=4 and studied by means of HPLC-DAD-MS, HRSEC-RID and Isothermal Titration Calorimetry (ITC). The results showed noticeably differences in the interactions between the MPs fractions and the flavanol extract depending on the pH values. 

References

[1] C. Alcalde-Eon, et al. (2019). Food Res. Int., 126; 108650.
[2] E. Manjón, et al. (2020). J. Agric. Food Chem. 25; 13459
[3] Y. Ruiz-García et al. (2014). Carbohydr Polym. 114; 102.

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Manjón Elvira1, Bosch-Crespo Diana Marelys1, Dueñas Montserrat1 and Escribano-Bailón Mará Teresa1

1Department of Analytical Chemistry, Nutrition and Food Science, Universidad de Salamanca.

Contact the author

Keywords

Saccharomyces cerevisiae, climate change, mannoproteins, flavanols, astringency.

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Soil, vine, climate change – what is observed – what is expected

To evaluate the current and future impact of climate change on Viticulture requires an integrated view on a complex interacting system within the soil-plant-atmospheric continuum under continuous change. Aside of the globally observed increase in temperature in basically all viticulture regions for at least four decades, we observe several clear trends at the regional level in the ratio of precipitation to potential evapotranspiration. Additionally the recently published 6th assessment report of the IPCC (The physical science basis) shows case-dependent further expected shifts in climate patterns which will have substantial impacts on the way we will conduct viticulture in the decades to come. Looking beyond climate developments, we observe rising temperatures in the upper soil layers which will have an impact on the distribution of microbial populations, the decay rate of organic matter or the storage capacity for carbon, thus affecting the emission of greenhouse gases (GHGs) and the viscosity of water in the soil-plant pathway, altering the transport of water. If the upper soil layers dry out faster due to less rainfall and/or increased evapotranspiration driven by higher temperatures, the spectral reflection properties of bare soil change and the transport of latent heat into the fruiting zone is increased putting a higher temperature load on the fruit. Interactions between micro-organisms in the rhizosphere and the grapevine root system are poorly understood but respond to environmental factors (such as increased soil temperatures) and the plant material (rootstock for instance), respectively the cultivation system (for example bio-organic versus conventional). This adds to an extremely complex system to manage in terms of increased resilience, adaptation to and even mitigation of climate change. Nevertheless, taken as a whole, effects on the individual expressions of wines with a given origin, seem highly likely to become more apparent.
Read More

MAPPING OF GAS-PHASE CO₂ IN THE HEADSPACE OF CHAMPAGNE GLASSES BY USING AN INFRARED LASER SENSOR UNDER STATIC TASTING CONDITIONS

From the chemical angle, Champagne wines are complex hydro-alcoholic mixtures supersaturated with dissolved carbon dioxide (CO₂). During the pouring process and throughout the several minutes of tasting, the headspace of a champagne glass is progressively invaded by many chemical species, including gas-phase CO₂ in large majority. CO₂ bubbles nucleated in the glass and collapsing at the champagne surface act indeed as a continuous paternoster lift for aromas throughout champagne or sparkling wine tasting [1]. Nevertheless, inhaling a gas space with a concentration of gaseous CO₂ close to 30% and higher triggers a very unpleasant tingling sensation, the so-called “carbonic bite”, which might completely perturb the perception of the wine’s bouquet.

Read More

Characterization of vine performance using remote sensing tools

Today, a variety of remote sensing tools are used to characterise plant performance. However, the vine is rarely studied, as a major crop specificity is canopy discontinuity. Registered images of the vineyard are anisotropic, therefore difficult to analyse.

Read More

Development of bioprospecting tools for oenological applications

Wine is the result of a complex biochemical process. From a microbiological point of view, the grape berry is characterised by a heterogeneous microbiota composed of different microorganisms (yeasts, bacteria and filamentous fungi) which will play a predominant role in the quality of the final product. At this level, yeasts play a predominant role in the chemistry of wine, as they

Read More

Volatile Organic Compound markers of Botrytis cinerea infection in artificially inoculated intact grape berries

The addition of partially dehydrated grapes to enrich must composition for producing complex dry/sweet wines represents a traditional practice in several regions of the world. However, the environmental conditions of dehydration chambers may facilitate the infection of Botrytis cinerea Pers. by promoting disease and provoking large grape losses. B. cinerea attack can induce alterations in the profile of volatile organic compounds (VOCs), which could be detected by sensors specifically trained to detect infection/disease-related compounds. These sensors could facilitate the early detection of the infection, consequently allowing to adjust some dehydration parameters.

Read More