terclim by ICS banner
IVES 9 IVES Conference Series 9 INVESTIGATION OF MALIC ACID METABOLIC PATHWAYS DURING ALCOHOLIC FERMENTATION USING GC-MS, LC-MS, AND NMR DERIVED 13C-LABELED DATA

INVESTIGATION OF MALIC ACID METABOLIC PATHWAYS DURING ALCOHOLIC FERMENTATION USING GC-MS, LC-MS, AND NMR DERIVED 13C-LABELED DATA

Abstract

Malic acid has a strong impact on wine pH and the contribution of fermenting yeasts to modulate its concentration has been intensively investigated in the past. Recent advances in yeast genetics have shed light on the unexpected property of some strains to produce large amounts of malic acid (“acidic strains”) while most of the wine starters consume it during the alcoholic fermentation. Being a key metabolite of the central carbohydrate metabolism, malic acid participates to TCA and glyoxylate cycles as well as neoglucogenesis. Although present at important concentrations in grape juice, the metabolic fate of malic acid has been poorly investigated. In this work, we used 13C-labeled malic acid to understand the main routes of its consumption and its de novo production. Two strains selected for their opposed malic acid metabolism were compared by combining several analytical chemistry techniques. The isotopic enrichment of intracellular amino acids was measured by GC-MS, the relative quantification of intra- cellular and extracellular labeled compounds was achieved by 2D-NMR, and the absolute quantification of labeled and unlabeled extracellular organic acids was achieved by LC-MS/MS. Although, both strains consume most of the malic acid provided, the “acidic strain” produces de novo malic acid during the second part of the alcoholic fermentation. In addition, 13C-filiation analyses provided evidence that most of the TCA is fed by glycolytic pyruvate and/or by cytosolic acetyl-CoA. Our results also confirmed that malic acid may be a secondary source of TCA cycle during alcoholic fermentation especially in high malic acid consuming strains that has an efficient malo-ethanolic fermentation. Finally, 13C-labeled compounds belonging to amino acids, alcoholic fermentation and neoglucogenesis pathways were identified, highlighting the pleiotropic position of malic acid in both catabolic and anabolic routes.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Vion Charlotte1,2, Bloem Audrey3, Valette Gilles4, Da Costa Gregory2, Richard Tristan2, Camarasa Carole3, Marullo Philippe 1,2

1. Biolaffort, Bordeaux, FRANCE
2. UMR 1366 Œnologie, Université de Bordeaux, INRAE, Bordeaux INP, BSA, ISVV
3. UMR SPO, Univ Montpellier, INRAE, Institut Agro, 34060 Montpellier, France
4. IBMM, Univ Montpellier, CNRS, ENSCM, 34000 Montpellier, France

Contact the author*

Keywords

13C-labeling, malic acid, central carbon metabolism

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

SENSORY IMPROVEMENT OF DEALCOHOLISED WINES

Interest and willing-ness to buy alcohol-free wines by customers is increasing for several years [1]. Due to the rising relevance of dealcoholised wines it is the objective of this study to contribute to a better understanding of the flavor variation among dealcoholised wines and to explore enological measures, how to improve final quality.
First a range of commercial, alcoholfree white wines were analysed by the holistic sensory method projective mapping, including a question for hedonic acceptance. Based on the combination of a non-target-HS-SPME-GC/MS analysis with sensory analysis we obtained a clustering of the wines into three groups.

PROBING GRAPEVINE-BOTRYTIS CINEREA INTERACTION THROUGH MASS SPECTROMETRY IMAGING

Plants in their natural environment are in continuous interaction with large numbers of potentially pathogenic and beneficial microorganisms. Depending on the microbe, plants have evolved a variety of resistance mechanisms that can be constitutively expressed or induced. Phytoalexins, which are biocidal compounds of low to medium molecular weight synthesized by and accumulated in plants as a response to stress, take part in this intricate defense system.1,2
One of the limitations of our knowledge of phytoalexins is the difficulty of analyzing their spatial responsiveness occurring during plant- pathogen interactions under natural conditions.

WHICH TERROIR-RELATED FACTORS INFLUENCE THE MOST VOLATILE COMPOUND PRODUCTION IN COGNAC BASE WINE?

Cognac is a famous spirit produced in southwest France in the region of the eponymous town from wines mainly from Vitis vinifera cv. Ugni blanc. This variety gives very acidic and poorly aromatic base wines for distillation which are produced according to a very specific procedure. Grapes are picked at low sugar concentrations ranging 13-21 °Brix and musts with high turbidity (>500 NTU) are fermented without sulphite addition [1]. Fermentative aromas, as esters and higher alcohols, are currently the main quality markers considered in Cognac spirits.

PHOTOCHEMICAL DEGRADATION OF TRYPTOPHAN IN MODEL WINE: IMPACT OF HEAVY METALS AND OXYGEN ON 2-AMINOACETOPHENONE FORMATION

The wine industry worldwide faces more and more challenges due to climate change, such as increased dryness in some areas, water stress, sunburn and early harvesting during hot summer temperatures¹. One of the resulting problems for the wine quality might be a higher prevalence of the untypical aging off-flavor (ATA)². A substance, which Rapp and Versini made responsible for ATA, is the 2-aminoace-tophenone (2-AAP)³. 2-AAP in wine causes a naphthalene, wet towels, wet wool, acacia flower or just a soapy note⁴.

HOW DO ROOTSTOCKS AFFECT CABERNET SAUVIGNON AROMATIC EXPRESSION?

Grape quality potential for wine production is strongly influenced by environmental parameters such as climate and agronomic factors such as rootstock. Several studies underline the effect of rootstock on vegetative growth of the scions [1] and on berry composition [2, 3] with an impact on wine quality. Rootstocks are promising agronomic tools for climate change adaptation and in most grape-growing regions the potential diversity of rootstocks is not fully used and only a few genotypes are planted. Little is known about the effect of rootstock genetic variability on the aromatic composition in wines; thus further investigations are needed.