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Effect of grape maturity on aroma-active compounds in Pinot noir wine was investigated using stir bar sorptive extraction-gas chromatograph-mass spectrometry (SBSE-GC-MS). High correlation coefficient (> 0.95) and low standard deviation (< 10%) were obtained for all aroma-active compounds of interest. Two vintages of Pinot noir wines with three different grape maturities each were analyzed. Statistical analysis showed that both grape maturity and growing year significantly affected the aroma composition of the final wine. Analysis of wine samples from the same vintage indicated that grape maturity could affect aroma compounds in different ways, based on their biochemical formation in the wines. For most short-chain fatty acid esters, there were no obvious trends with grape maturity, however, the concentrations of ethyl 2-methylpropanoate and ethyl 3-methylbutanoate consistently decreased with grape maturity. The decreasing trend was also observed for other esters including ethyl cinnamate, ethyl dihydroxycinnamate, and ethyl anthranilate, with the exception of ethyl vanillate, while C13 norisoprenoids, monoterpenes, and guaiacols had increasing trends with grape maturation.

The aroma profiles of Oregon Pinot Noir wines were investigated with aroma extract dilution analysis (AEDA). The wines were extracted with pentane-diethyl ether, the aromas were distilled using solvent-assisted flavour evaporation (SAFE) and separated into acidic/water-soluble and neutral/basic fractions. In the acidic/water-soluble fraction, 2-phenylethanol and 3-methyl-1-butanol showed the highest AEDA values, followed by 2-methylpropanoic acid, butanoic acid, 2-methylbutanoic acid, 3-methylbutanoic acid, 2-methylpropanol, hexanol, trans-3-hexenol, cis-3-hexenol, benzyl alcohol, 3-methylthio-1-propanol, 3-ethylthio-1-propanol, linalool and geraniol (all with FD ≥ ≥ ≥ ≥ ≥ 64). In the neutral/ basic fraction, ethyl 2-methylpropanoate, ethyl butanoate, 3-methylbutyl acetate, ethyl hexanoate, and benzaldehyde had very high AEDA values (all with FD ≥ ≥ ≥ ≥ ≥ 64), followed by ethyl 3-methylbutanoate, 3-methylbutyl 2-methylpropanoate, ethyl octanoate, ethyl decanoate, benzyl acetate, phenylethyl formate, phenylethyl acetate, ethyl dihydrocinnamate, ethyl anthranilate, 3-methylthio-1-propanal, citronellal, whisky lactone and γ γ γ γ γ -nonalactone (all with FD ≥ ≥ ≥ ≥ ≥ 16). Overall, the results indicated that there is no single compound that characterizes the aroma of Pinot Noir, and that the characteristic aroma comes from a blend of numerous compounds.

The impact of deficit irrigation during berry development on Merlot wine volatile composition was investigated in this study. Own-rooted Merlot vines grown in a commercial vineyard in Idaho were supplied with 100 or 35% of their estimated crop evapotranspiration needs throughout the berry development. Wines were produced from those grapes from the 2002, 2003, and 2004 growing seasons. Volatile compounds in the wines were analyzed using the stir bar sorptive extraction-gas chromatography-mass spectrometry technique. The results demonstrated that despite vintage differences in volatile composition, in each of 3 years of this study, deficit irrigation during berry development had a consistent effect on wine volatile composition. Wine produced from deficit-irrigated vines had increased amounts of vitispiranes, beta-damascenone, guaiacol, 4-methylguaiacol, 4-ethylguaiacol, and 4-vinylguaiacol relative to wine produced from well-watered vines. Deficit irrigation had no effect on the concentrations of other measured volatiles such as esters and terpenes.