terclim by ICS banner
IVES 9 IVES Conference Series 9 LARGE SURVEY OF THE CHEMICAL COMPOSITION OF WINES RESULTING OF THE PRESSING OF RED WINE MARC. FIRST RESULTS

LARGE SURVEY OF THE CHEMICAL COMPOSITION OF WINES RESULTING OF THE PRESSING OF RED WINE MARC. FIRST RESULTS

Abstract

In the Bordeaux vineyards, press red wine represents about 15% of the volume of wines. Valuing this large volume of press wine is necessary from an economic point of view, of course, but also because of their organoleptic contribution to the blend. Nevertheless, there is a lack of recent knowledge on the composition of press wines. This work aims to establish an initial assessment of their composition (aromatic and polyphenolic) and to set up hypothesis on to the links with their sensorial identity.

Measurements and dosages were done in 50 press wines and their associated free-run wines. Wines are monovarietal batch from: cabernet-sauvignon and merlot from Saint-Estèphe, Médoc, France. The vintage is 2021. The production of wines was done in the estate to the classical process. The grapes, picked up and harvested by hand, were destemmed, sorted using an optical sorter and crushed. During vinification, extractions were adapted to each batch by daily tastings. Maceration did not exceed 21 days. After pressing, the wines were kept in oak-barrels. Three months after pressing, all the wines were tasted and were categorized according to their aptitude to be incorporated in the blend of the premium wine. Samples were kept at 12°C in bottles.
For the study of the aromatic composition: dimethyl sulphide (DMS) and its precursors (HS-SPME-GC-MS); higher alcohols (GC-FID) and 33 esters (HS-SPME-GC-MS) were measured. Concerning the analysis of phenolic compounds: anthocyanin monomers (HPLC-UV) and flavonols (HPLC-fluo.) were determined. Indices such as IPT, CieLAB, pH, AT have also been measured.
As expected, the results showed a significant difference between the two grape varieties. For each grape variety, PCA suggest differences between the press wines and the drop wines for all compounds. For the aromatic compounds, total tannins and flavonols: the press wines are more concentrated than the free-run wines. There are no significant differences between the press and free-run wines concerning anthocyanins. More statistical analysis permits to highlight unexpected separation of compounds according to the pressing step. The data also highlight links between the composition and the sensorial categorization.
In conclusion, the study permits to propose a first molecular database and to explore the origins of the sensorial categorization of that wines.
The experiment is renewed during the 2022 harvest and new compounds are added to the database.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Margot Larose1,2; Michael Jourdes¹; Eric Boissenot³, Vincent Decup²; Stéphanie Marchand¹

1. ISVV-Univ. Bordeaux, Bordeaux INP, Bordeaux Sciences Agro, UMR 1366 OENOLOGIE, Bordeaux France
2. Château Montrose, Saint-Estèphe France
3. Laboratoire Boissenot, Lamarque, France

Contact the author*

Keywords

Press-wine, Phenolic composition, Aromatic composition, Sensorial categorization

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

OPTIMIZING THE IDENTIFICATION OF NEW THIOLS AT TRACE LEVEL IN AGED RED WINES USING NEW OAK WOOD FUNCTIONALISATION STRATEGY

During bottle aging, many thiol compounds are involved in the expression of bouquet of great aged red wines according to the quality of the closure.1,2 Identifying thiol compounds in red wines is a challenging task due several drawbacks including, the complexity of the matrix, the low concentration of these impact compounds and the amount of wine needed.3,4
This work aims to develop a new strategy based on the functionalisation of oak wood organic extracts with H₂S, to produce new thiols, in order to mimic what can happen in red wine during bottle aging. Following this approach and through sensory analysis experiments, we demonstrated that the vanilla-like aroma of fresh oak wood was transformed into intense “meaty” nuances similar to those found in old but non oxidized red wines.

UNEXPECTED PRODUCTION OF DMS POTENTIAL DURING ALCOOLIC FERMENTATION FROM MODEL CHAMPAGNE-LIKE MUSTS

The overall quality of aged wines is in part due to the development of complex aromas over a long period (1.) The apparition of this aromatic complexity depends on multiple chemical reactions that include the liberation of odorous compounds from non-odorous precursors. One example of this phenomenon is found in dimethyl sulphide (DMS) which, with its characteristic odor truffle, is a known contributor to the bouquet of premium aged wine bouquet (1). DMS supposedly accumulates during the ten first years of ageing thanks to the hydrolysis of its precursor dimethylsulfoniopropionate (DMSp.) DMSp is a possible secondary by-product from the degradation of S-methylmethionine (SMM), an amino acid iden- tified in grapes (2), which can be metabolized by yeast during alcoholic fermentation.

THE EFFECT OF DIFFERENT TERROIRS ON AROMA COMPOUNDS OF ‘KALECIK KARASI’ WINES

Kalecik Karası is a domestic grape variety of Turkey, originating from Kalecik district, 80 km from Ankara. Although there is no definite evidence, it is known that it was used in wine production by many civilizations that lived in the Anatolian region, especially the Hittites. Compared to other black wine grapes, it stands out with its low tannin content, rich fruity aroma and complex structure. In good vintages, red fruits such as strawberries, cherries and raspberries stand out in the aroma profile. Although its structure is elegant, it has the potential to age and develop similar to the ‘Pinot Noir’ wine of the Burgundy region. This offers a complex aroma structure including red flowers, earth and ripe fruits.

CHANGES IN METABOLIC FLUXES UNDER LOW PH GROWTH CONDITIONS: CAN THE SLOWDOWN OF CITRATE CONSUMPTION IMPROVE OENOCOCCUS OENI ACID-TOLERANCE?

Oenococcus oeni is the main Lactic Acid Bacteria responsible for malolactic fermentation, converting malic acid into lactic acid and carbon dioxide in wines. Following the alcoholic fermentation, this second fermentation ensures a deacidification and remains essential for the release of aromatic notes and the improvement of microbial stability in many wines. Nevertheless, wine is a harsh environment for microbial growth, especially because of its low pH (between 2.9 and 3.6 depending on the type of wine) and nutrient deficiency. In order to maintain homeostasis and ensure viability, O. oeni possesses different cellular mechanisms including organic acid metabolisms which represent also the major pathway to synthetize energy in wine.

ANTHOCYANINS EXTRACTION FROM GRAPE POMACE USING EUTECTIC SOLVENTS

Grape pomace is one of the main by-products generated after pressing in winemaking.Emerging methods, such as ultrasound-assisted extraction with eutectic mixtures, have great potential due to their low toxicity, and high biodegradability. Choline chloride (ChCl) was used as a hydrogen bond acceptor and its corresponding hydrogen bond donor (malic acid, citric acid, and glycerol: urea). Components were heated at 80 °C and stirred until a clear liquid was obtained. Distilled water was added (30 % v/v). A solid-liquid ratio of 1 g pomace per 10 ml of eutectic solvent was used.