Determination of Odorants in Varietal Wines from International Grape Cultivars (Vitis vinífera) Grown in NW Spain

This work was carried out to investigate the odorants found in ten varietal wines from different internationalgrape cultivars (Merlot, Cabernet Sauvignon, Pinot noir, Tempranillo, Sauvignon blanc, Riesling,Chardonnay, Pinot gris, Pinot blanc and Gewürztraminer) grown in northwest Spain. Monoterpenes,alcohols, fatty acids, ethyl esters, acetates and volatile phenols were determined by gas chromatographymassspectrometry (GC-MS). The results showed that Gewürztraminer white wines had the highestconcentration of volatile compounds (35.7 mg/L). Monoterpenes, linalool, terpineol, citronellol and nerolwere detected only in Riesling and Gewürztraminer white wines. In the red wines, Cabernet Sauvignonfollowed by Merlot wines showed the highest concentration of total volatile composition (55.60 mg/L and50.90 mg/L respectively), characterised by a higher concentration of alcohols. Based on the individual odourthreshold, white Gewürztraminer and red Pinot noir wines showed the highest total OAV value. ANOVAhas shown significant differences among wines. Principal component analysis performed a grouping ofthe monovarietal wines – Sauvignon blanc-Pinot blanc-Riesling and Pinot gris gris-Gewürztraminer in thewhite wines, and Cabernet Sauvignon-Tempranillo in the red wines

Early leaf removal impact on volatile composition of Tempranillo wines

Background: Early defoliation is a very innovative technique in viticulture used for yield management. The effects of early leaf removal performed manually and mechanically at two different phenological stages, pre-bloom and fruit set, on the volatile composition of Tempranillo (Vitis vinifera L.) wines were studied. Volatiles were identified and quantified by gas chromatography. Results: Early leaf removal only modified the total concentrations of C 6 compounds and acetates, whereas total alcohols, esters, volatile acids and terpenes remained generally unaffected. Early defoliation induced a significant reduction in C 6 compounds and increased the concentrations of acetates in Tempranillo wines. An effect of timing (pre-bloom vs fruit set) alone was observed for all acetates analysed. Regarding the method of defoliation (manual vs mechanical), significant differences in some ethyl ester (ethyl-2-methylbutyrate and ethyl octanoate) and volatile acid concentrations were observed among treatments. Ethyl octanoate, 2-phenylethyl acetate, 3-methylbutyl acetate and hexanoic acid, with OAV (odour activity value) > 1 and mainly fruity and floral odour descriptors, showed higher levels after early defoliation treatments compared with non-defoliated vines. Principal component analysis illustrated the difference in wines from defoliated and non-defoliated treatments based on their volatile composition. Conclusion: It can be concluded that early leaf removal significantly modified the wine aroma compounds, increasing or decreasing several of these compounds. © 2011 Society of Chemical Industry