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…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.