Talanta 50 (1999) 413–421 Optimization of an extraction method of aroma compounds in white wine using ultrasound Dolores Hernanz Vila a , Fco. Jose ´ Heredia Mira b , Rafael Beltran Lucena a , M a Angeles Ferna ´ndez Recamales a, * a Dpto. Quı ´mica y Ciencia de los Materiales. E.P.S. Uniersidad de Huela, 21819 La Rabida, Spain b Dpto. Nutricio ´n y Bromatologı ´a, F. De Farmacia, Uniersidad de Seilla, Seilla, Spain Received 7 September 1998; received in revised form 2 January 1999; accepted 12 February 1999 Abstract A simple and rapid method is described for the extraction of wine volatile compounds. The procedure was based on the ultrasonic-assisted extraction using a mixing of n -pentane – diethylether (1:2) as solvent. Factorial designs have been used to optimize the sonication process. Factors such as sample volume, extraction time and solvent volume were considered. A statistical approach was used to find suitable conditions for the ultrasound extraction of aroma compounds of wine. A factorial design at two-level revealed that lower sample volume (100 ml instead of 125 ml) and solvent volume of 50 ml instead of 60 ml contributed to improve extraction efficiency. Performance of the method was evaluated, and the procedure applied to the analysis of aroma compound in white wines from ‘Condado de Huelva’ (Spain). © 1999 Elsevier Science B.V. All rights reserved. Keywords: Aroma compounds; Ultrasound extraction; Wine 1. Introduction Volatile compounds play an important role in the organoleptic characteristic of wines. It has been recognized that the aroma constituents of the wine have a leading contribution to its varietal character. Several hundred chemically different flavor compounds, such as alcohols, esters, or- ganic acids, aldehydes, ketones, and monoterpe- nes, have been found in wines. The flavor of a wine is extremely complex, due to the great number of compounds present which have different polarities, volatilities and, more- over, are found in a wide range of concentrations. Hence, sample preparation, especially, extraction and concentration of aroma compounds remains one of the critical areas in aroma volatiles analysis. Continuous liquid – liquid extraction has been widely used in sample preparation for the deter- mination of wine volatiles [1,2]. Other methods include liquid – liquid extraction, XAD-2 resin ex- * Corresponding author. Tel.: +34-9-59530213; fax: +34- 9-59350962. E-mail address: recamale@uhu.es (M. Ferna ´ndez Reca- males) 0039-9140/99/$ - see front matter © 1999 Elsevier Science B.V. All rights reserved. PII:S0039-9140(99)00128-9