First results on the chemical composition of red wines from the pressing of marc
In the Bordeaux vineyards, press wine represents approximately 15% of the total volume of wine produced. Valuing this large volume of wine is necessary from an economic point of view, but also because of their organoleptic contribution to the blend, and their contribution to the construction of wines for laying down. Therefore, this study was developed considering the lack of recent scientific knowledge on the composition of red press wines. The aim of this study is to establish an initial assessment of their chemical composition including aromatic compounds and a phenolic part.
To achieve this objective, quantification were performed in 50 press wines and their associated free-run wines. Wines were monovarietal batch from two of the main grape varieties vinified in Bordeaux: cabernet-sauvignon and merlot. The vintage was 2021 and the vines were located in Saint-Estèphe (Médoc France). A selection of analyzes was carried out. For the aromatic composition: dimethyl sulfide (DMS) and its potential (HS-SPME-GC-MS); higher alcohols (GC-FID); and 32 esters (HS-SPME-GC-MS) were measured. Regarding the analysis of phenolic compounds, anthocyanin monomers (HPLC-UV) and flavanols (HPLC-fluo) were determined. Indices such as IPT, CieLAB, pH, AT were also measured. As expected, the results showed a significant difference between the two grape varieties cabernet-sauvignon and merlot. For the aromatic compounds, the press wines of the two grape varieties were more concentrated than the free run wines, and for the phenolic compounds, the press wines were more concentrated in total tannins and flavanols.
In conclusion, the study of a certain number of aromatic and phenolic compounds in press wines, as well as the associated free-run wines, made it possible to participate in the constitution of a first database. This also shows a contradiction between the results obtained and the declarations of the few old studies mentioning press wines.
1) PEYNAUD, E Knowledge and work of wine. 1971. 1e éd, p179-180
Issue: ICGWS 2023
1Université de Bordeaux, INRAE, Bordeaux INP, Bordeaux Sciences Agro, UMR 1366, ŒNO, ISVV, F-33882 Villenave d’Ornon, France
2Château Montrose, Saint-estèphe, France
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aromatic composition, phenolic composition, press wine