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…

ACIDIC AND DEMALIC SACCHAROMYCES CEREVISIAE STRAINS FOR MANAGING PROBLEMS OF ACIDITY DURING THE ALCOHOLIC FERMENTATION

In a recent study several genes controlling the acidification properties of the wine yeast Saccharomyces cerevisiae have been identified by a QTL approach [1]. Many of these genes showed allelic variations that affect the metabolism of malic acid and the pH homeostasis during the alcoholic fermentation. Such alleles have been used for driving genetic selection of new S. cerevisiae starters that may conversely acidify or deacidify the wine by producing or consuming large amount of malic acid [2]. This particular feature drastically modulates the final pH of wine with difference of 0.5 units between the two groups.

Read More

Molecular approaches for understanding and modulating wine taste

Wine consumers generally demand wines having a perception of softer tannins and less ripe, having a heaviness and richness on palate (full-body wine) with a limpid and stable color. However, polyphenol
(tannins)-rich wines have been also correlated with unpleasant taste properties such as astringency and
bitterness when perceived at high intensities. Modulating these unpleasant properties could be important for consumer’s approval of wines.

Read More

EXPLORING THE ROLE OF TRANSITION METAL IONS IN THE EVOLUTION OF ESTERS COMPOSITION OF YOUNG WHITE WINE DURING AGEING

Young white wines are typically released to the market a few months after harvest, to be consumed within a year, when their fresh fruity aromas are still dominant and appealing to modern consumers. Esters, particularly higher alcohol acetates (HAAs) and ethyl esters of fatty acids (EEFAs), play a central role in the fruity expression of young white wines [1]. However, these esters are known to undergo significant hydrolysis during the first months of aging [1, 2].

Read More

REDUCING NITROGEN FERTILIZATION ALTERS PHENOLIC PROFILES OF VITIS VINIFERA L. CV. CABERNET GERNISCHT WINE OF YANTAI, CHINA

Nitrogen (N) fertilizer is important for grape growth and the quality of wine. It is essential to address the mismatch between N application and wine composition. Cabernet Gernischt (Vitis vinifera L.), as one of the main wine-grape cultivars in China, was introduced to Yantai wine region in 1892. This grape cultivar is traditionally used for quality dry red wine with fruit, spices aroma, ruby red and full-bodied wines. In order to regulate vine growth and improve grape and wine quality, Cabernet Gernischt grapevines were subjected to decreased levels of N treatments, compared to normal N supply treatment, during grape growing seasons of 2019 and 2020.

Read More

SIP and save the planet: a sensory and consumer exploration of australian wines made from potentially drought-tolerant white wine grapes

In order to attenuate the effects of climate change on the ability to cultivate quality wine grape vines in Australia, it is essential to adapt to the projected less favourable Australian climate scenarios. One response may be to convert a portion of the current grapevine plantings to those varieties that demand less water and can tolerate increased heat. This investigation aimed to (i) generate sensory profiles and (ii) obtain knowledge about Australian wine consumers’ preferences and opinions of Australian wines made from potentially drought tolerant, white wine grape varieties not traditionally cultivated in Australia. A Rate-All-That-Apply (RATA) sensory panel (n = 49) generated sensory profiles of 44 commercial white wines made from 7 different white grape varieties (Arinto, Fiano, Garganega, Greco, Verdejo, Verdelho and Vermentino), plus two benchmark examples each of an Australian Riesling, Pinot Gris and Chardonnay wine.

Read More