Evolution of Ellagitannins in Spanish, French, and American Oak Woods during Natural Seasoning and Toasting

Abstract

The evolution of tannins in Spanish oak heartwood of Quercus robur L., Quercus petraea Liebl.,Quercus pyrenaica Wild., and Quercus faginea Lam. was studied in relation to the processing of wood in barrel cooperage. Their evolution was compared with that of French oak of Q. robur (Limousin, France) and Q. petraea (Allier, France) and American oak of Quercus alba L. (Missouri), which are habitually used in cooperage. Two stages of process were researched: the seasoning of woods during 3 years in natural conditions and toasting. Total phenol and total ellagitannin contents and optical density at 420 nm of wood extracts were determined. The ellagitannins roburins A-E, grandinin, vescalagin, and castalagin were identified and quantified by HPLC, and the molecular weight distribution of ellagitannins was calculated by GPC. During the seasoning process the different ellagitannin concentrations decreased according to the duration of this process and in the same way as those in French and American woods. The toasting process also had an important influence on the ellagitannin composition of wood. Roburins A-E, grandinin, vescalagin, and castalagin decreased during this process in the Spanish wood species, in the same proportion as in the French and American ones. Also, the seasoning and toasting processes lead to qualitative variations in the structure of ellagitannins, especially in the molecular weight distribution, as was evidenced by GPC analysis of their acetylated derivatives.

Extraction of Some Ellagic Tannins and Ellagic Acid from Oak Wood Chips (Quercus pyrenaica L.) in Model Wine Solutions: Effect of Time, pH, Temperature and Alcoholic Content

“…After 104 extraction days the values that were determined varied from 2.4 to 6.6 mg/L (ellagic acid equivalent). These results confirm the trends found in other studies in which other extraction methods, oak wood species (include Quercus pyrenaica specie) or green untoasted and toasted wood, were used (Viriot et al, 1994;Puech et al, 1996;Feuillat et al, 1997;Fernandez de Simon et al, 1998;Matricardi & Waterhouse, 1999;Cadahía et al, 2001). Feuillat et al (1997) lar conditions.…”

Quercus humboldtii(Colombian oak): Characterisation of wood phenolic composition with respect to traditional oak wood used in oenology

“…faginea of different origins (Fernández de Simón et al, 1996;Cadahía et al, 2001b;Caldeira et al, 2006;Fernández de Simón et al, 2006;Garcia et al, 2012). Thus, the identified phenolic compounds in Q. humboldtii, as in other studied oaks, were phenolic acids, ellagic, gallic, syringic and vanillic, and phenolic aldehydes, coniferyl, sinapic, syringaldehyde and vanillin (Table I).…”

“…analyses of LMWP and ellagitannins LMWP were analysed by the method described by Cadahía et al (2001a) and the analysis of ellagitannins was performed according to the method of Cadahía et al (2001b …”

“…However, no significant differences were found between this wood and that of Q. Alba. The fact that Q. sessiliflora contained higher amounts of the individual ellagitannins than Q. alba has been widely reported (Canas et al, 2000;Cadahía et al, 2001b). In addition, the concentration of ellagitannins is affected by a large number of interdependent factors, including the species (Canas et al, 2000;Doussot et al, 2002;Jordão et al, 2007), forest origin (Doussot et al, 2002;Jordão et al, 2007), heartwood age (Matricardi and Waterhouse, 1999), grain coarseness (Jordão et al, 2007) among others.…”

Selected Process Alternatives for Biomass Refining: A Review

“…Ferulic and p-coumaric acids (the most abundant hydroxycinnamic acids) are linked to arabinoxylans or pectins through ester bonds. In hardwoods, condensed tannins (proanthocyanidins) and hydrolyzable ellagitannins make also part of the phenolic fraction [67,68], whereas acids (gallic, vanillic and ellagic) and aldehydes (syringaldehyde and sinapaldehyde) have been also detected [69].…”