ellagitannin and vanillin

Malolactic fermentation (MLF) and oak barrels aging are two oenological processes which modify wine composition and sensory characteristics. The effect of MLF-container (stainless steel tanks, barrels) and barrel toasting (T1, T2, T3) on ellagitannin concentration, volatile composition and sensory attributes of Chardonnay wines was evaluated. Barrel toasting had higher impact on ellagitannin content than MLF-container. When comparing both MLF-modalities, barrel-fermented wines exhibited greater amounts of vanillin and whiskey-lactones but lower concentrations of fruity aroma compounds. Regarding sensory analysis, greater citrus and floral aromas were perceived for MLF-tank wines, and higher nuts aroma for MLF-barrel wines. Using barrels as MLF-containers i) did not change the aroma perception defining Chardonnay character (peach, apricot and gun flint); ii) did not impact the aromatic intensity and persistence, sweetness, acidity, mouthfeel volume and/or bitterness; and iii) did not confer significantly higher overall woody aromas which might mask fruity, floral and mineral (gun flint) character.

Topics: Benzaldehydes; Chromatography, Gas; Chromatography, High Pressure Liquid; Fermentation; Food Handling; Humans; Hydrolyzable Tannins; Lactones; Phenols; Quercus; Time Factors; Volatile Organic Compounds; Wine; Wood

Ellagitannins and aromatic compounds evolution in Cabernet Sauvignon wines macerated in oak barrels for a year was studied. Identical barrels with different toastings (medium toasting, medium toasting with watering, Noisette) were used in French, Italian and USA cellars. Ellagitannins increased by 84-96% with aging time, as did woody volatiles, by 86-91% in French wines and 23-35% in Italian wines, while fruity aroma compounds declined by 50-57% in the French and Italian wines over a 12-months period. Nevertheless, other behaviors and different kinetics rates for these compounds were observed depending on barrel toasting, wine matrix and their interactions. Perceived overall woody intensity was closely related to trans-whiskey lactone, guaiacol and vanillin, whereas astringency and bitterness were significantly linked to ellagitannins (p<0.05). This is the first study that evaluates the toasting effect on wines from different countries matured in the same oak barrels.

Topics: Benzaldehydes; Food Handling; France; Guaiacol; Humans; Hydrolyzable Tannins; Italy; Lactones; Quercus; Sensation; Taste; United States; Volatile Organic Compounds; Wine; Wood

The chemical composition of cooperage oak wood is highly variable, depending upon the tree species (Quercus robur L. versus Quercus petraea Liebl.), its geographic location, and the single-tree effect. In the process of cask-making, natural seasoning and toasting contribute strongly to the modification of the oak wood chemical composition and therefore influence wine cooperaging. HPLC and GC quantification of ellagitannins and volatile compounds such as whiskey-lactones, eugenol, and vanillin over a sample set of 61 pedunculate oaks and 72 sessile oaks originating from six different forests showed that natural drying leads to a decrease of the ellagitannins and total extractives content level and a quasi constant level of the volatile compounds. Toasting (medium type) drastically enhanced the loss of ellagitannins and the gain in volatile compounds. Statistical treatment showed that the species effect remained significant throughout the process of drying and toasting, but not the provenance. The poor correlation with ring width of extractives levels measured on fresh timber remained unchanged as did the single-tree effect, with high variability found for all chemical parameters. These results provide further evidence that cooperage oak selection should not be based solely on the wood grain or the provenance but rather on a species-provenance combination.

Topics: Benzaldehydes; Chromatography, Gas; Chromatography, High Pressure Liquid; Desiccation; Eugenol; Hydrolyzable Tannins; Lactones; Quercus; Species Specificity; Tannins; Volatilization; Wine; Wood