Contribution of oak lignans to wine taste: chemical identification, sensory characterization and quantification

How stereochemistry influences the taste of wine: Isolation, characterization and sensory evaluation of lyoniresinol stereoisomers

“…Nevertheless, the specific optical rotation of lyoniresinol 1 was reported to be close to zero in oak wood [6] indicating a mixture of two enantiomers 1a and 1b (Figure 2) in the extracted compound. Thus, all sensory studies concerning lyoniresinol until now have been carried out using a racemic mixture purified from oak wood and the properties of each enantiomer have never been individually assessed.…”

“…Indeed, previous studies have established the presence in oak wood of lyoniside 3 and nudiposide 4, two native xylopyranosidederivatives of (+)-and (−)-lyoniresinol, respectively [28,29]. For this purpose, lyoniside 3 and nudiposide 4 purified as previously described [6] were heated in acidic conditions under inert atmosphere to hydrolyze the acetal formed between the xylose aldehyde and the primary alcohol (C9') of lyoniresinol, as shown in Figure 3. TFA was used to acidify the solution since it could be easily removed in vacuo from the crude reaction mixture.…”

“…Recently, a lignan from oak wood called lyoniresinol was shown to exhibit bitterness [5]. Another study showed that lyoniresinol is present in wines aged in new oak barrels at concentrations higher than its perception threshold (1.5 mg/L in white wine), establishing its key contribution to the increase in bitterness observed during oak ageing [6].…”

“…Galloyl, glucosyl and xylosyl derivatives were thus discovered, some of them exhibiting bitterness but with a lower intensity than lyoniresinol [6].…”

Phenolic Composition and Related Properties of Aged Wine Spirits: Influence of Barrel Characteristics. A Review

“…There is evidence on the relationship between: the vanilla aroma and vanillin concentration [24,49,50]; the bitterness and phenolic acids, their ethyl esters, and (+)-lyoniresinol concentrations [48,[51][52][53][54]. Among these properties, the vanilla aroma should be highlighted due to its outstanding importance for aged wine spirit quality [55][56][57]. The relationship between astringency and ellagitannin and gallotannin concentrations is still unclear for thesekind of beverages [48,[51][52][53][54]58,59].…”