terclim by ICS banner
IVES 9 IVES Conference Series 9 DETERMINATION OF FREE AMINO ACIDS, AMINO ACID POTENTIAL AND PROTEASE ACTIVITY IN THE LEES AND STILL WINES OF CHAMPAGNE

DETERMINATION OF FREE AMINO ACIDS, AMINO ACID POTENTIAL AND PROTEASE ACTIVITY IN THE LEES AND STILL WINES OF CHAMPAGNE

Abstract

Prior to winemaking, organic or mineral nitrogen compound concentrations are usually measured in the vineyard and in grape musts. These indicators facilitate vine cultivation decisions, usually through yield or vigor. During vinification, yeast and bacteria metabolize nitrogen compounds in the musts in order to generate biomass. After fermentation, the microorganisms rerelease a part of this nitrogen as soluble compounds into the wines. Another part remains bound in the lees and can be lost during racking. The must’s natural nitrogen quantities, additional supplements during fermentation, and lees contact management enhance the release of nitrogen compounds to the wines. During ageing these nitrogen compounds – primarily the amino acids – are implicated in the generation of odorous compounds such as heterocycles(1).

Yeast cellular autolysis facilitates the diffusion of proteins and peptides into the wine. Associated with protease activity, amino acids can be released during ageing. The organic nitrogen content of wines and lees post-fermentation is not yet fully understood. This study explored the quantities of free amino acids, potential amino acids, and protease activity in champagne still wines and their corresponding lees. To achieve this analysis, a new quantification method to detect protease activity was developed using fluorescein isothiocyanate bound to a casein substrate.

In addition, the current method used to quantify potential amino acids after acid hydrolysis was optimized and associated to the previously published HPLC/FLD method for quantifying free amino acids(2). The methods were also adapted for quantifying lees. This analytical toolbox allows the observation of nitrogen compound kinetics over time, and was subsequently applied to sixteen young wines and their corresponding lees. The results of this study highlight a high variability in amino acid content between wines and lees. This suggests huge differences between amino acids levels in wine and in lees. No direct correlation was observed between lees quantity and the concentration of free and potential amino acids, indicating the mechanism is more complex. After 5 months of wine ageing with lees contact, the wines with lower levels of amino acids showed higher protease activity. That result encourages us to continue studying yeast lees and their variable capacities to release amino acids into wine over time.

 

1. Le Menn N, Marchand S, De Revel G, Demarville D, Laborde D, Marchal R. N,S,O-Heterocycles in Aged Champagne Reserve Wines and Correlation with Free Amino Acid Concentrations. J Agric Food Chem. 2017;65(11):2345-56.
2. Pripis-Nicolau L, De Revel G, Marchand S, Beloqui AA, Bertrand A. Automated HPLC method for the measurement of free amino acids including cysteine in musts and wines; first applications. J Sci Food Agric. 2001;81(8):731-8.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Nicolas Le Menn¹, Sera Goto1,2, Stéphanie Marchand¹

1. Université de Bordeaux, ISVV, EA 4577, INRA, USC 1366 OENOLOGIE, 33140 Villenave d’Ornon, France
2. Champagne Veuve Clicquot, 13 rue Albert Thomas, 51100 Reims, France

Contact the author*

Keywords

Nitrogen, relesable nitrogen, lees, ageing

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

ANTIOXIDANT CAPACITY OF INACTIVATED NON-SACCHAROMYCES YEASTS

The importance of the non-Saccharomyces yeasts (NSY) in winemaking has been extensively reviewed in the past for their aromatic or bioprotective capacity while, recently their antioxidant/antiradical potential has emerged under winemaking conditions. In the literature the antioxidant potential of NSY was solely explored through their capacity to improve glutathione (GSH) content during alcoholic fermen- tation [1], while more and more studies pointed out the activity of the non-glutathione soluble fraction released by yeasts [2].

Read More

IDENTIFICATION OF NEW RESVERATROL DERIVATIVES FORMED IN RED WINE AND THEIR BIOLOGICAL PROPERTIES

Stilbenes are natural bioactive polyphenols produced by grapevine. Recently, we have reviewed the na- tural presence of these compounds in wines [1]. This study showed that the resveratrol and its glycoside, the piceid, are the most abundant stilbenes in wines. Resveratrol is a well-known stilbene with a wide range of biological activities. Due to its specific structure, resveratrol can be oxidized in wines to form various derivatives including oligomers [2]. In this study, we investigate the resveratrol and piceid transformation in wines.

Read More

BIOSORPTION OF UNDESIRABLE COMPONENTS FROM WINE BY YEAST-DERIVED PRODUCTS

4-Ethylphenol (EP) in wine is associated with organoleptic defects such as barn and horse sweat odors. The origin of EP is the bioconversion reaction of p-coumaric acid (CA), naturally present in grapes and grape musts by contaminating yeasts of the genus Brettanomyces bruxellensis.
Yeast cell walls (YCW) have shown adsorption capacities for different compounds. They could be applied to wines in order to adsorb either CA and/or EP and thus reduce the organoleptic defects caused by the contaminating yeasts.

Read More

A synthesis approach on the impact of elevated CO2 on berry physiology and yield of Vitis vinifera

Besides the increase in global mean temperature the second main challenge of a changing climate is the increase in atmospheric carbon dioxide (CO2) in relation to physiology and yield performance of grapevines. The benefits of increasing CO2 levels under greenhouse environment or open field studies have been well investigated for various annual crops. Research under free carbon dioxide enrichment on field-grown perennial plants such as grapevines is limited to a few studies. Further, chamber and greenhouse experiments have been conducted mostly on potted vines under eCO2 conditions.

Read More

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.

Read More