IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Evaluation of mannoprotein formation by different yeast strains by enzymatic analysis of mannose and tribological estimation of astringency

Evaluation of mannoprotein formation by different yeast strains by enzymatic analysis of mannose and tribological estimation of astringency

Abstract

A positive role of mannoproteins on wine stability and red wine mouth sensations has been widely described. Commercial mannoproteins are available and some yeast strains are offered with a higher formation of mannoproteins. However, mannoprotein analysis is complex and its determination at cellar level is very limited. An adaptation of a relatively simple method of analysis of mannoproteins was developed, based on concentration of poly saccharides by membrane filtration, hydrolysis and enzymatic determination of mannose. The method was applied to the analysis of the mannoprotein content of wines fermented with different yeast strains deemed to produce high amounts of mannoproteins. Significant differences in mannoprotein concentration of red wines fermented with different strains was obtained. A tribological estimation of astringency also showed differences in the friction coefficient between wines. Sensory evaluation of wines using RATA (Rate all that Apply) with a panel of trained enologists showed significant differences only in some mouth parameters like dryness, grease, structure and bitter. Reasonable correlations between mannose concentration and friction coefficient were obtained only in wines coming from an earlier harvest. Correlations of mannose and friction coefficient with sensorial parameters were in general low except for dryness with friction coefficient in the early harvested wines. Even if significant, differences in mannoprotein concentration between strains were moderate, what can explain these results. Findings of this work propose an effect of mannoproteins on
sensory perception and opens the possibility to explore their effect on wine quality

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Bordeu Edmundo¹, Vidal Josefina¹, Vargas Sebastián², Zincker Jorge², Schober Doreen²and Brossard Natalia ¹

¹Department of Fruit Trees and Enology, Pontifical Catholic University of Chile, Santiago, Chile
²Center for Research and Innovation Concha y Toro (CII

Contact the author

Keywords

Mannoproteins, Yeast strains, RATA (Rate all that apply), Oral lubrication, Astringency

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Les effets du terroir ou l’expression des potentiels à valoriser

Research into the effects of the Terroir is of major interest for the wine sector. The study of Terroir-Vine-Grape relations, even if it is complex, is fundamental for all viticulture: indeed, the quality of the grape must be the result of the most reasoned agro-viticultural management of the vine possible, which must first, to respect a production balance. The goal sought by the winegrower is to obtain a wine, the optimized result of the interactions Terroir-Grape variety. This link to the terroir is therefore essential to establish by taking into account on the one hand the behavior of the vine (which is the cause), and on the other hand, its effects on the grapes and finally on the wine.

Biotype diversity within the autochthonous ‘Bobal’ grapevine variety

Bobal is the second most widely grown Spanish red grape variety (54,165 has), mainly cultivated in the Valencian Community and especially, in Utiel-Requena region (about 67% of 34,000 has). In this study, agronomic and enological parameters were determined in 98 biotypes selected during 2018 and 2019 in more than 50 vineyards over 50 years-old in the Utiel-Requena region. Moreover, a multi-criteria approach considering temperature and rainfall (Fig. 1A), among other parameters, was made to establish three different zones within the region (Fig. 1B), where in the future the selected biotypes will evaluated. In fact, in 2020, 4 replicates and 12 vines per biotype were planted in an experimental vineyard to preserve this important intra-cultivar diversity.

The evolution of wine tourism: trends, challenges and opportunities for the future

The wine tourism industry has experienced significant transformation over the past years, accelerated by the COVID-19 pandemic.

Sensory profile of wines obtained from disease-resistant varieties in La Rioja

The European wine industry is facing multiple challenges derived from climate change and the pressure of different fungal diseases that are compromising the production of traditional varieties. A sustainable alternative maybe the adoption of resistant varieties.
In this study, we have evaluated the enological potential of 9 resistant varieties (5 white and 4 red varieties) in La Rioja. Microvinifications were carried out with three biological replications. Oenological parameters were very diverse with acid content varying from 2.6 g/L to 6.6 g/L.

Study of the oenological potential of varieties resistant to cryptogamic diseases and drought to anticipate varietal selection in Occitanie

In the context of climate change and the growing need to reduce the use of phytosanitary products, the exploration of disease-resistant grape varieties and/or adapted to drought conditions is becoming crucial for the wine industry in certain regions of France, such as Occitanie. Currently, exploring the oenological potential of varieties by analyzing their biochemical composition before and after winemaking comes rather late in the varietal selection process.