Subregional survey of aroma compounds in Marlborough Sauvignon blanc wines

Abstract

Background and Aims: Marlborough is the largest wine-growing region in New Zealand and Sauvignon Blanc varieties represent over 60% of the vineyard area. The main compounds responsible for the most intense aromas in Sauvignon Blanc wines have been assumed to be methoxypyrazines and varietal thiols; however, the aromatic potential of Sauvignon Blanc wines should not be limited to these compounds. Methods and Results: Commercially pressed juices from seven Marlborough subregions were fermented using replicated research-scale winemaking over two harvests. Fifty-five compounds were quantified in the resulting wines, including varietal thiols, methoxypyrazines, reduced sulfur compounds, esters, terpenes, C6 and higher alcohols, fatty acids, C13-norisoprenoids, cinnamates, and aminobenzoates. At least 21 compounds were identified that were present at a concentration above their perception threshold or can enhance the aroma impact of other compounds. Many aroma compounds showed a similar concentration across the subregions and the two seasons, while the concentration of the prominent varietal thiol 3-mercaptohexanol was higher in the second year. Conclusion: Considerable diversity exists in the concentration of aroma compounds in Sauvignon Blanc wines across the Marlborough subregions. The ‘green’ characters ascribed to wines from certain subregions may be linked to a lower concentration of fruity esters as much as to differences in methoxypyrazines, C6 alcohols and certain varietal thiols. Significance of the Study: The profiles of aroma compounds in Marlborough Sauvignon Blanc wines have been more clearly defined and the extent of subregional differences has been evaluated for various classes of aroma compounds.