Original article The effect of light on the composition of some volatile compounds in wine: an HS-SPME-GC-MS study Luciana Cellamare, Maurizio D’Auria,* Lucia Emanuele & Rocco Racioppi Dipartimento di Chimica, Universita` della Basilicata, Via N. Sauro 85, 85100 Potenza, Italy (Received 4 October 2007; Accepted in revised form 14 December 2007) Summary The HS-SPME-GC-MS analysis of Fiano di Avellino (white wine, Southern Italy) and Aglianico del Vulture (red wine, Southern Italy) showed the presence of ethyl acetate, 2-methyl-1-propanol, 2-methyl-1-butanol (MB), 2-methylbutyl acetate (MBA), ethyl hexanoate (EH), diethyl butanedioate (DB), ethyl octanoate (EO) and ethyl decanoate (ED). UV irradiation of both the wines in a Pyrex vial with a 15-W low pressure mercury arc showed an extensive degradation of all the compounds. After 24 h irradiation in the red wine, ethyl acetate decreased from 208 mg L )1 to 58 mg L )1 , DB from 16.7 to 4 mg L )1 , MBA from 19 to 3 mg L )1 , 2-methyl-1-propanol disappeared and MB decreased from 796 to 92.5 mg L )1 . Only in the case of DB, MBA, EH, EO and ED in the red wine the degradation occurred after an initial increase of the concentrations of the esters. The irradiation of the esters in the presence of riboflavin showed a clear degradation of the esters (9%–17%). The irradiation of both the wines in the original bottles for 7 days showed an extensive degradation of all the volatile compounds observed in the wines. 2-Methyl-1-propanol disappeared while 90% of MB disappeared. The amount of the esters decreases in the range 65%–91%. Keywords Gas chromatography, mass spectrometry, solid phase microextraction, UV-vis exposition, volatile compounds, wine. Introduction Solid phase microextraction (SPME) has showed to be a powerful instrument for the determination of volatile organic compounds (VOCs) (Pawliszyn, 1997). In the past, we reported several applications of SPME in the analysis of VOCs from truffles (Mauriello et al., 2001, 2004), olive oil (Bentivenga et al., 2001, 2002, 2004b), saffron (D’Auria et al., 2004b, 2006b), horseradish (D’Auria et al., 2004a), honey (Bentivenga et al., 2004a), thymus, oregano, lavender (D’Auria et al., 2005) and cheese (D’Auria et al., 2006a). SPME has been used also for the determination of VOCs in wine (Freire et al., 2001; Pozo-Bayon et al., 2001; Rocha et al., 2001; Bonino et al., 2002; Marengo et al., 2002; Rodriguez-Bencomo et al., 2002; Demyttenaere et al., 2003; Ferreira & Guedes de Pinho, 2003; Castro et al., 2004; Alves et al., 2005; Kafkas et al., 2006). Some years ago the analysis of Sherry wine exposed to UV-vis radiation showed that an increase of the amount of volatile compounds can be observed (Benitez et al., 2003). Esters and acids showed a sharp tendency to increase during irradiation; with the exception of 2- methyl-1-butanol, hexanol and 2-methyl-1-propanol, the same tendency was found in alcohols present in wine. In addition, aldehydes and ketones increased during irradiation. This result was not in agreement with our report where SPME was used in order to estimate the modifications occurred in volatile compounds in champagne after UV irradiation (D’Auria et al., 2003). In fact, while most of the alcohols found did not change their concentration after irradiation, a sharp reduction was observed in the amounts of esters [ethyl acetate (EA), ethyl butanoate, ethyl 2-hydroxypropanoate, 3-methyl-1-butanol acetate, diethyl butanedioate (DB), ethyl octanoate (EO) and ethyl decanoate (ED)]. The esters in wine are important constituents of the aroma. In fact, the high variability of the ester fraction has an effect on the intensity of fruity notes in the aroma profile (Belitz et al., 2004). Then, both the possible increase and decrease can influence the aroma of the wine. Furthermore, the results reported by Benitez et al. (2003) showed that the increase of the ester fraction was higher in topaz glass (cut-off near 600 nm, but 20% transmittance at 350 nm) than in transparent one (cut- off at 300 nm). Then, also the nature of the glass bottles can influence the organoleptic properties of wine. Most of the wine is sold in supermarkets where the wine bottles are exposed for a large period to artificial light. This exposition can modify the aroma profile of the wine. We have to know the nature of all the *Correspondent: Fax: +39 0971 202223; e-mail: maurizio.dauria@unibas.it International Journal of Food Science and Technology 2009, 44, 2377–2384 2377 doi:10.1111/j.1365-2621.2008.01723.x Ó 2008 Institute of Food Science and Technology