Optimization of HS SPME Fast GC-MS for High-Throughput Analysis of Strawberry Aroma

Abstract

Strawberry aroma is one of the most complex fruit aromas and is typically analyzed by headspace solid-phase microextraction gas chromatography–mass spectrometry (GC-MS). However, the runtime on a conventional GC-MS is rather long and therefore, not ideal in situations requiring high-throughput techniques. By equipping a conventional GC-MS with a Modular Accelerated Column Heater and a short narrow-bore capillary column, the runtime could be reduced 10 times without loss of resolution and sensitivity. In this manuscript, we present the optimization of this headspace solid phase microextraction fast GC-MS technique resulting in the determination of an optimal extraction time of 30 min, extraction temperature of 40 °C and incubation time of 10 min. A 50/30 μm DVB-CAR-PDMS fiber proved to be the best fiber choice. Sample preparation was carefully evaluated. Storage of the samples at −80 °C did not affect the aroma profile. However, during blending and elevated temperature, aroma changes have to be taken in consideration. At 40 °C, the abundance of mainly esters increased as compared to room temperature. During blending hexanal, 2-hexenal, hexanoic acid, and 2,3-butanedione increased in abundance. Finally, it was found that aroma intensities change according to strawberry tissue type. The outer tissues contained higher levels of mainly esters compared to the inner tissue types.