Headspace Solid-Phase Microextraction: A Useful and Quick Tool for the Traceability and Quality Assessment of Wine Cork Stoppers

Abstract

Natural cork remains a favored option for sealing high-quality wine bottles, despite its high cost for wineries. The cork industry faces the challenge of certifying the quality and traceability of these corks, with physical–chemical characterization being a valuable tool in establishing these parameters. While cork taint compounds must be absent or in low concentrations, the volatile fraction of cork contains numerous compounds that, even in small amounts, can impact the wine’s final aroma. Moreover, these volatile compounds are indicative of the geographical origin of the cork planks used to make the stoppers. In this work, a total of 68 volatile compounds (alkanes, terpenes, benzenic compounds, aldehydes, ketones, acids, esters, alcohols and furanic and pyranic compounds) from natural corks of different qualities and origins were identified, using a fast and sensitive technique: headspace solid-phase microextraction coupled to gas chromatography–mass spectrometry (HS-SPME-GC-MS). Based on these volatile compounds, it was possible to establish differences between corks of different origins, although no discernible differences were detected in the samples of differing visual qualities, as this is a subjective parameter largely dependent on the cork’s external appearance. These findings show that the analysis of the volatile composition of corks via HS-SPME-GC-MS can be used as a quick tool for tracking their traceability and selecting the most appropriate parameters at each stage of processing to minimize the increase in unwanted compounds.

Keywords

• natural corks
• volatile compounds
• traceability
• sensory quality
• HS-SPME