Identification of green note compounds in malt whisky using multidimensional gas chromatography

We studied green note compounds in malt whisky using multidimensional GC-MS-olfactometry (MDGC-MS-O). Two aldehydes and three alcohols were shown to contribute to the green note: E,Z-2,6-nonenal and E-2-nonenal, and 1-octen-3-ol, 4-hepten-1-ol and nonan-2-ol, respectively. Malt whiskies with high green note scores organoleptically contained more of the aldehydes and nonan-2-ol than those with low scores. This is the first time that E,Z-2,6-nonadienal, 1-octen-3-ol, and 4-hepten-1-ol have been identified in malt whisky. These compounds are related to lipid oxidation and degradation, and formation may be due to the action of lipoxygenase. In addition, MDGC-MS-O was effective in examining small amounts of compounds in malt whisky, which contains many volatile, since this method enables the volatiles in a complicated matrix to he highly resolved without the influence of large amounts of volatiles. Copyright (C) 2002 John Wiley Sons, Ltd.