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…

Trends and challenges in International Wine Trade. The need for new strategies for companies and regions.

Trends already extended for more than 12 years show a decline in both consumption and international trade, particularly in volume. However, there are also positive signs in several categories of wine, segments and markets, as well as a better trend in terms of value. How are these trends affecting wine producers and distributors? Are they short or long term? do they mean radical and permanent changes to which a way of adaptation has to be found or are they just temporary changes that may only require some calm? How are companies adapting to these new trends? Which are their effects on wine regions?
Read More

Copper reduction strategy for sangiovese in organic viticulture

Organic viticulture requires copper based treatments for bunch protection even though an intensive employment is no longer admitted because of its low leaching and phytotoxicity in the soil. UE Reg. 1981/2018 set copper employment to 4 kg/ha for year or 28 during 7 years with an absolute level allowed of 6 Kg/ha although those limits were decreased frequently.

Read More

Significance of factors making Riesling an iconic grape variety

Riesling is the iconic grape variety of Germany and accounts for 23% of the German viticulture acreage, which comprises 45% of the worldwide Riesling plantings. Riesling wines offer a wide array of styles from crisp sparkling wines to highly concentrated and sweet Trockenbeerenauslese or Icewines. However, its thin berry skin makes Riesling more vulnerable to detrimental environmental threats than other white wine varieties.  

Read More

Rare earth elements distribution in grape berries

Rare Earth Elements (REEs) include 15 lanthanides, yttrium and scandium. Their occurrence in soil and plants seems to be closely tied to the geological composition of the underlying mother rock, to the physical and chemical properties of the soil and to the specific ability of the plant to take up and accumulate these microelements.

Read More

INVESTIGATION INTO MOUSY OFF-FLAVOR IN WINE USING GAS CHROMATOGRAPHY-MASS SPECTROMETRY WITH STIR BAR SORPTIVE EXTRACTION

Mousy off-flavor is one of the defects of microbial origin in wine. It is described as a particularly unpleasant defect reminiscent of rodent urine (a “dirty mouse cage”), and grilled foods such as popcorn, rice, crackers, and bread crust. Prior to the 2010s, mousiness was very uncommon but it has been becoming more frequent in recent years. It is often associated with an increase in pH as well as certain oenological practices, which tend to significantly decrease the use of sulfur dioxide.

Read More