Comparative study of the aromatic profile of different kinds of wine cork stoppers

Abstract

The sensory properties and aromatic composition of macerates (in wine-like medium) of different types of cork stoppers (five synthetic and three natural corks) have been determined. After the sensory description, extracts of the macerates were obtained using a customary head space technique and analyzed by semiquantitative gas chromatography–olfactometry (GC–O). The active odourants present in the macerates were determined using this technique and ranked by their potential importance. From the sensory point of view, the eight samples were grouped into two categories with distinctive sensory properties. The first category was formed by non-synthetic stoppers and was described using the terms “sweet, toasted, sweet wood, and flowery-muscat”. Remarkably, all these sensory terms are normally used in wine tasting. The second category consisted of synthetic samples. This category included a sample with a clear rubber aroma and two samples with a cork/mushroom aromatic note. The results of GC–O confirmed the sensory study. Non-synthetic samples had complex profiles of 10–20 aromatic compounds, all well known natural components of healthy wine. In contrast, the GC–O profiles of the synthetic stoppers were extremely simple and consisted of few odourants. The rubber aroma may be due to m-cresol and an unknown odourant with RI 1758 (in DB-WAX column), while the cork/mushroom note was caused by a single odourant that elutes in a DB-WAX column at RI 1223 (identified as 1-hepten-3-one).