Semipreparative reversed-phase liquid chromatographic fractionation of aroma extracts from wine and other alcoholic beverages

The suitability of reversed-phase HPLC for the semi-preparative fractionation of aroma extracts from wine and other alcoholic beverages has been explored. Aroma extracts are separated in a 250x10-mm Kromasil-C-18 column using a water-ethanol gradient system as mobile phase. It has been demonstrated that the chromatographic separation does not induce any chemical change in the sample components. The maximum volume that can be injected without altering efficiency is as high as 2 ml if ethanolic extracts are injected, and slightly less in the case of less polar extracts. Aroma extracts are injected directly without the need of any pretreatment. As major compounds elute first, it is possible to fractionate all the volatiles contained in a 1-1.5-1 sample without peak distortion or mass overload problems. The usefulness of the:method has been demonstrated by fractionating an extract from a Chardonnay wine to get 15 fractions that showed different aromas. The GC analysis with olfactometric and MS detection of those fractions has allowed us to identify more than 70 aroma compounds and to signal some of them as potential key aromas of Chardonnay wine. (C) 1999 Elsevier Science B.V. All rights reserved.