White wines aged in barrels with controlled tannin potential exhibit correlated long-term oxidative stability in bottle

Abstract

Chardonnay and Sauvignon blanc wines aged in oak wood barrels with low and medium tannin potentials were discriminated for their abilities to resist against oxidation during bottle storage. The oak wood tannin potential was positively correlated to wines antioxidant capacity after 2 and 4 years of bottle aging. Untargeted molecular analysis revealed that the Sauvignon blanc metabolome was more affected by the tannin potential than the Chardonnay. Supervised statistical analysis highlighted the extensive oak wood contribution to the wine chemical fingerprints. Wines aged in barrel of medium tannin potential were associated with higher concentrations in antioxidant compounds such as dipeptides. Moreover, quantitative differences were observed between oak barrel derived volatile compounds. Sauvignon blanc volatile thiols appeared to decrease during bottle aging, regardless of the oak tannin potential. This study highlights the post bottling positive impact of oak wood barrel aging on wines oxidative stability, related to oak barrel tannin potential.

Keywords: Aging; Chardonnay; DPPH; Gas chromatography mass spectrometry; Liquid chromatography mass spectrometry; Sauvignon blanc; metabolomics.

Fig. 1

Comparison of the antioxidant capacity of Chardonnay (hatches) and Sauvignon blanc (full) wines aged in low tannin potential (blue) or in medium (yellow) TP at 2 and 4 years of bottle aging under cellar conditions. Fisher's Least Significant Difference post-hoc tests were employed to reveal statistical differences indicated through different letters (p < 0.05). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

PCA score plot of untargeted UPLC-Q-ToF-MS/MS analysis in negative mode of Chardonnay (triangles) and Sauvignon blanc (squares) aged in low (blue) or medium (yellow) tannin potential after four years of bottle aging. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 3

Supervised classification using partial least squares discriminant analysis (PLS-DA) of UPLC-Q-ToF-MS/MS data from all wines (CHA + SAU) after four years of bottle storage, with the tannin potential (low: blue; medium: yellow) as discriminant variable (A). The model diagnostic was evaluated through the AUROC curve (B). The relevant features (VIPs) were presented as histogram (C). A diagram was employed to present the retention time (D) and mass range (F) diversity as density plot and the scatter plot (E) summarize both information. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 4

PCA biplots of the first two PCs for the absolute quantitation of the 11 volatile compounds analyzed for both Chardonnay (triangles, A) and Sauvignon blanc (squares, B) wines aged in low tannin potential (blue) or in medium TP (yellow) after four years of bottle aging. Significant different amount in compound were symbolized by “*” for p < 0.05 and by “**” for p < 0.01 following compound name. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)