OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 Grape solids: new advances on the understanding of their role in enological alcoholic fermentation

Grape solids: new advances on the understanding of their role in enological alcoholic fermentation

Abstract

Residual grape solids (suspended particles) in white and rosé musts vary depending on the clarification pro-cess. These suspended solids contain lipids (more especially phytosterols) that are essential for yeast meta-bolism and viability during fermentation in anaerobic conditions. We present here recent advances on the understanding of the role of the solid particles during alcoholic fermentation in liquid phase. A microscopic approach (epifluorescence with fluorescent probes, confocal and electronic microscopy) al-lowed to better characterize grape solids physical-chemical structure and lipidic fraction. Then, the lipidic composition of grape solids from white, rosé and red winemaking processes was analyzed. ß-sitosterol was the main sterol, but there was considerable variability of overall sterol content of solids depending on their origin. Must turbidity was not representative of sterol content. The use of mutant strains allowed us to pro-vide a model of sterol assimilation in Saccharomyces cerevisiae cell. Finally, experimental fermentations were performed in synthetic musts supplemented with the studied grape solids. Sterol content was deter-minant for the fermentation kinetics when lipids were the limiting yeast nutritional factor. This impact can be explained by the fact that sterols i) favor yeast nitrogen assimilation and consequently cell growth and maximum fermentation rate, ii) improve cell viability at the end of fermentation reducing risks of sluggish fermentation. Thus, taking into account the sterol content of the must should allow wine-makers to improve control of white and rosé fermentations.

DOI:

Publication date: June 10, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Erick Casalta, Aude Vernhet, Catherine Tesnière, Jean-Michel Salmon, Jean-Marie Sablayrolles

Supagro Montpellier Campus de la Gaillarde – 2, place Viala 34000 Montpellier Inra UMR Sciences pour l’oenologie Montpellier Inra UE Pech-Rouge Gruissan

Contact the author

Keywords

grape solids, sterols, yeast, alcoholic fermentation 

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Metodología para la zonificación de áreas vitícolas: aplicación en un area modelo del Penedés

Se propone una metodología para la zonificación del viñedo, a partir de las características climáticas, edáficas y geomorfológicas, en una área de 3700 ha del Penedés

Read More

NEW TREATMENTS FOR TEMPRANILLO WINES BY USING CABERNET SAUVIGNON VINE-SHOOTS AND MICRO-OXYGENATION

Toasted vine-shoots as enological additive represents a promising topic due to their significant effect on wine profile. However, the use of this new enological tool with SEGs varieties different than wine and combined with others winemaking technologies, such as micro-oxygenation (MOX), has not been studied so far, despite this combination could result in wine with high chemical and organoleptic quality.

Read More

Under-vine management effects on grapevine vegetative growth, gas exchange and rhizosphere microbial diversity

The use of cover crops under the vines might be an alternative to the use of herbicides or tillage, improving grapevine quality and soil characteristics. The aim of this research was to study the implications of different management strategies of the soil under the vines (herbicide, cultivation or cover crops) on grapevine growth, water and nutritional status, gas exchange parameters and belowground microbial communities.
The experimental design consisted in 4 treatments applied on 35L-potted Tempranillo vegetative grapevines with 10 replicates each grown in an open-top greenhouse in 2022 and 2023. Treatments included two cover crop species (Trifolium fragiferum and Bromus repens), herbicide (glyphosate al 36%) and an untreated control.

Read More

Modelling leaf water potential from physiological and meteorological variables – A machine learning approach

Viticulture is a key economic sector in the mediterranean region. However, climate change is affecting global viticulture, increasing the frequency of heatwaves and drought events.

Read More

Dormancy conundrum: thermal requirements plasticity to reach budburst may be explained by annual environmental dynamics

Deciphering grapevine dormancy is crucial in the current context of climatic challenges: advancing budburst phenology and increased late frost probabilities, observed in the last decades and expected to further increase, require deeper understanding. Beyond higher mean temperatures, abiotic stresses such as water deficit have also been emphasized as actors. In this framework, we aimed at exploring new methodologies for tracking dormancy cycle and testing the interplay on its regulation of temperature dynamics and drought.
In a first experiment, twenty-one Vitis vinifera varieties were monitored during ecodormancy and budburst over three years.

Read More