Attualmente il gusto di tappo è uno dei problemi più gravi per il settore enologico e sugheriero. I principali composti responsabili di questo difetto sono i policloroanisoli, tra cui in particolare il 2,4,6-tricloroanisolo (TCA),che si formano dai corrispondenti precursori fenolici. La ricerca ha preso in esame vari aspetti:-studio dell'impatto sensoriale del TCA in diversi tipi di vino;-ottimizzazione di metodi di estrazione e analisi di policlorofenoli e policloroanisoli nel sughero e nel vino;-studio della microflora presente nel sughero in base alla capacità di degradare i policlorofenoli. I risultati hanno mostrato che l'uso di un unico valore soglia per la percezione del TCA nei vini non sembra idoneo; i metodi messi a punto sono risultati adeguati per la determinazione di clorofenoli e cloroanisoli; i microrganismi hanno presentato una capacità di produrre TCA differente a seconda del ceppo utilizzato. / Today cork taint is one of most serious problems for wine and cork industries. The primary compounds considered responsible for this defect are chloroanisoles, especially 2,4,6-trichloroanisole (TCA), that are produced from their phenolic precursors. The PhD work was carried out studying different aspects of this subject: -effect of wine style on the perception of TCA;-optimization of extraction and analysis methods to determine chlorophenols and chloroanisoles in wine and cork; biodegradation ability of mould isolated from cork to produce TCA from TCP. The results showed that the use of generic threshold values for all wines does not seem to be accurate enough; methods optimized are adequate to detect chlorophenols and chloroanisoles; micro-organisms tested can produce TCA from TCP.

D'entre els defectes organolèptics associats al vi, en destaca l'anomenat "gust de suro" habitualment vinculat a la presència de cloroanisoles, els quals són productes de l'activitat microbiana formats a partir dels corresponents clorofenols. La present tesi doctoral recull, en primer lloc, metodologies analítiques adreçades principalment a la determinació dels compostos clorofenòlics (2,4,6-triclorofenol, 2,3,4,6-tetraclorofenol i pentaclorofenol) en el control de qualitat dels taps suro, emprant dissolucions hidroalcohòliques com a medi de maceració o d'extracció i utilitzant les tècniques d'extracció en fase sòlida (SPE) i microextracció en fase sòlida (SPME) acoblades a la cromatografia de gasos (GC).En segon lloc, per tal de dur a terme l'anàlisi de cloroanisoles juntament amb els seus precursors en matrius de suro s'ha avaluat un mètode basat en l'extracció amb dissolvent orgànic, el qual ha estat aplicat per a l'estudi de diferents sistemes d'eliminació d'aquests anàlits en la matriu citada. En darrer lloc, s'han proposat metodologies per l'anàlisi de mostres de vi, en les quals d'una banda s'han determinat els compostos clorofenòlics utilitzant la SPME i de l'altra el 2,4,6-tricloroanisole i el 2,4,6-tribromoanisole mitjançant l'acoblament de la SPE i la injecció de grans volums (LVI) en el sistema cromatogràfic. / The organoleptic defect known as cork taint is associated with a musty or mouldy aroma in wine. Chloroanisoles, which are produced through a process of detoxification by fungal methylation of chlorophenolic compounds, are considered to be the main contributory substances. In the present work, analytical methods for the determination of chlorophenols (2,4,6-trichlorophenol, 2,3,4,6-tetrachloropheol and pentachlorophenol) in cork matrices using the solid-phase extraction (SPE) and the solid-phase microextraction (SPME) as preconcentration techniques were evaluated. Therefore, hydroalcoholic solutions have been proposed as extractant solvent in order to test the quality of cork stoppers.Furthermore, a methodology based on extraction with an organic solvent for the simultaneous determination of chloroanisoles and chlorophenols in cork matrices was proposed. This methodology was applied with the aim of checking the efficiency of several washing treatments to remove the target analytes in naturally contaminated cork samples.Finally, different procedures have been developed for the analysis of wine samples. On one hand, chlorophenols were quantified by employing a SPME method. On the other hand, a reliable SPE method coupled to large volume injection was proposed for the determination of both 2,4,6-trichloroanisole and 2,4,6-tribromoanisole.