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…

Isotopes to distinguish production system in Brazilian viticulture

Organic viticulture integrates practices aimed at foresting positive relationships among, vines, soil, and climate, with a focus on sustainability, social responsibility, and environmental protection. To safeguard production integrity, regulatory bodies worldwide conduct organic certifications in accordance with relevant regulations. Considering that agriculture practices influence the nitrogen, carbon and oxygen isotope composition, the study aimed to investigate the response of these isotopes in grape must cultivated by organic, biodynamic and conventional methods to distinguish between production systems.

Read More

Algae protein: fining agent for white wine, sustainable, non-allergenic and animal-free

The development of non-animal and non-allergenic alternatives to traditional protein fining agents used in winemaking is of critical importance in order to ensure consumer safety and production sustainability. This study evaluates the effect of protein extracted from three types of algae (spirulina, chlorella vulgaris and tetraselmis chuii) as fining agents on the polymeric proanthocyanidin content responsible for astringency, as well as their effect on the colour, phenolic composition and volatile aroma of two white wines (a and b).

Read More

Geological influences on terroir development

Geological influences on terroir development

Read More

Bentonite fining in cold wines: prediction tests, reduced efficiency and possibilities to avoid additional fining treatments

Bentonite fining is widely used to prevent protein haze in white wines. Most wineries use laboratory-scale fining trials to define the appropriate amount of bentonite to be used in the cellar. Those pre-tests need to mimic as much as possible the industrial scale fining procedure to determine the exact amount of bentonite necessary for protein stability. Nevertheless it is frequent that, after fining with the recommended amount of bentonite, wines appear still unstable and need an additional fining treatment. It remains a major challenge to understand why the same wine, fined with the same dosage of the same bentonite, achieves stability in the lab, but not in the cellar.

Read More

Swiss terroirs studies

A multidisciplinary approach aiming at studying the grape-growing areas also referred as “Terroir” was initiated a few years ago in Switzerland.

Read More