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…

To a better understanding of the impact of vine nitrogen status on volatile thiols from plot to transcriptome level

Volatile thiols contribute largely to the organoleptic characteristics and typicity of Sauvignon blanc wines. Among this family of odorous compounds, 3-sulfanylhexan-1-ol (3SH) and 4-methyl-4-sulfanylpentan-2-one (4MSP) have a major impact on wine flavor. These thiols are formed during alcoholic fermentation by the yeast from odorless and non-volatile precursors found in the berry and the must. The effect of vine nitrogen status on 3SH and 4MSP in Sauvignon blanc wine and on the glutathionylated and cysteinylated precursors of 3SH (Glut-3SH and Cys-3SH) was investigated in this study.

Enological potential of autochtonous grape cultivars from Castilla y León (Spain) to elaborate sparkling wines: polyphenolic and biogenic amines and amino acid composition of base wines

In white wines, Verdejo wine stands out because of its high content in total amino acids. The total content in biogenic amines was low in all wines analyzed and putrescine was the predominant biogenic amine.

Key genes in rotundone biosynthesis are affected by temperature, light, water supply, and nitrogen uptake

Rotundone accumulation and biosynthesis is a complicated process. Previous research highlighted that these phenomenons were affected under ecophysiological conditions by viticultural practices (e.g. defoliation or irrigation). Individually, these practices often impact several abiotic factors that are difficult to separate such as temperature, water or nitrogen status, or radiation. Such dissociation can be achieved under controlled environmental conditions using potted vines.

Haplotype-resolved genome assemblies of Chasselas and Ugni Blanc

Haplotype-resolved genome assemblies were produced for Chasselas and Ugni Blanc, two heterozygous real-field genetic pool Vitis vinifera cultivars by combining high-fidelity long-read sequencing (HiFi) and high‐throughput chromosome conformation capture (Hi-C). The telomere-to-telomere full coverage of the chromosomes allowed us to assemble separately the two haplo-genomes of both cultivars and revealed structural variations between the two haplotypes of a given cultivar.

Advancing grapevine science through genomic research

The seminar will examine the complexities and prospects of genomic research on Vitis species, characterize by exceptionally high heterozygosity and common interspecific gene flow. The seminar will showcase case studies highlighting the critical role of diploid genome references in grape research, specifically in areas such as aroma development, disease resistance, and domestication traits. It will also address the emerging focus on pangenomes within the Vitis genus, particularly in the context of genetic studies on naturally interbreeding populations.