Characterization of enological oak tannin extracts by multi-analytical methods approach - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Access content directly
Conference Poster Year :

Characterization of enological oak tannin extracts by multi-analytical methods approach

Aurélie Roland
Emmanuelle Meudec
Stéphanie Carrillo
  • Function : Author
  • PersonId : 1200079
Bertrand Robillard
  • Function : Author
  • PersonId : 1045817
Nicolas Sommerer
Céline Poncet-Legrand
Veronique Cheynier


Oak tannin extracts are commonly used to improve wine properties. The main polyphenols found in oak wood extracts are ellagitannins that release ellagic acid upon hydrolysis and comprise numerous structures. Moreover, oak tannin extracts contain other compounds giving a complex mixture. Consequently, the official OIV method based on gravimetric analysis of the tannin fraction adsorbed on polyvinylpolypyrrolidone is not sufficient to describe their composition and highlight their chemical diversity. Eight commercial oak tannins were characterized by a combination of analytical approaches, Polyphenols were analyzed using the official OIV method, UV spectrophotometry, UPLC-UV-MS analysis before and after acidic methanolysis, and HPLC-SEC-UV. Neutral sugars and polyols were determined as alditol acetates by GC-FID analysis, before and after hydrolysis. Finally, samples were compared by a non-targeted metabolomic approach based on UHPLC−HRMS/MS. Gravimetric analysis, absorbance values at 280 nm, and the quantities of ellagic acid released by methanolysis revealed some differences between samples, indicating variations in their tannin composition. This was confirmed by SEC analysis evidencing differences in tannin size distribution, particularly in larger polymer content. All samples contained significant quantities of sugars, and in particular xylose, mostly found in the linked form, and of quercitol, a polyol marker of oak origin. These compounds contributed to up to 25% of the whole extract composition, the proportions of free and combined sugars and polyols also showing large variations between tannins. Non targeted UPLC-HRMS analysis detected major ellagitannins such as vescalagin, castalagin, and roburins A-E, but also a large number of derivatives as well as other molecules such as lignans and quercotriterponosides, and highlighted large differences between samples. This work demonstrates the variability in the composition of commercial oak tannin extracts, likely to impact their properties, and emphasizes the need for detailed multi-method characterization in the frame of quality control and selection of tannins for specific applications.
Fichier principal
Vignette du fichier
OMW_Characterization of oak tannins extracts by multi-analytical methods approach.pdf (94.2 Ko) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

hal-04167983 , version 1 (21-07-2023)




  • HAL Id : hal-04167983 , version 1


Hélène Hallé, Kevin Pascotto, Aude Watrelot, Aurélie Roland, Emmanuelle Meudec, et al.. Characterization of enological oak tannin extracts by multi-analytical methods approach. OENO Macrowine 2023, Jul 2023, Bordeaux, France. ⟨hal-04167983⟩
11 View
3 Download


Gmail Facebook Twitter LinkedIn More