Optimisation of Headspace High Concentration Capacity method followed by comprehensive two-dimensional Gas Chromatography Mass Spectrometry applied to coffee brew aroma analysis

Abstract

HiSorb, as a novel HCC tool, was, here, successfully applied to the analysis of coffee brew aroma. The optimisation of extraction conditions (time, sample volume, and temperature) was achieved for HiSorb with PDMS coating. The resulting conditions were used to evaluate the analytical performances of the HiSorb and compare it with more common SPME (PDMS and DVB/CAR/PDMS coatings) methods. A Multi-Vial Multi-Cumulative Trapping (MV-MCT) approach was then explored to evaluate the performance gain over the single extraction approach and compare these two extraction tools. Finally, MV-MCT extraction was used with both HiSorb and DVB/CAR/PDMS SPME to evaluate and compare the level of information obtained through the study of the impact of coffee packaging on the VOC profile of the brewed beverage. The use of HiSorb as an automated SBSE alternative through the innovative Centri platform (Markes International Ldt.) led to much higher extraction yield than other usual SPME tools. The MV-MCT approach has shown that several reduced time cumulative extractions gave overall better response than the equivalent time in single extraction. However, and contrary to what has been recently demonstrated for Single-Vial Multi-Cumulative Trapping (SV-MCT) extraction, this approach increases the extraction of more volatile molecules while having a minor effect on semi-VOCs (for the equivalent time in single extraction). Finally, the MV-MCT approach with both HiSorb and DVB/CAR/PDMS SPME allowed a successful discrimination of the sample packaging through the extracted VOC profile. Moreover, the two extraction tools seem to be alternating and/or complementary concerning the level of information obtained.