Comparison of headspace pre-concentration techniques for volatile profiling of virgin olive oil by comprehensive two-dimensional chromatography

This study compares three headspace-based extraction techniques—Regular solid-phase microextraction (HS- SPME), vacuum-assisted SPME (Vac-HS-SPME), and probe-type sorptive extraction (HiSorb)—for the analysis of volatile organic compounds (VOCs) in virgin olive oil (VOO). Using a combined untargeted–targeted GC × GC–MS approach, 34 VOCs were selected. Vac-HS-SPME enhanced recovery of semi-volatile compounds linked to oxidative and microbiological defects, underrepresented by HS-SPME and HiSorb. Conversely, HS- SPME and HiSorb preferentially extracted low-molecular-weight lipoxygenase (LOX)-derived volatiles associated with green and fruity notes, with HiSorb showing broader coverage and stronger alcohol and aldehyde responses. ANOVA and Tukey's post hoc test (p < 0.05) indicated significant differences among techniques for 24 analytes. These findings provide method-oriented insights into VOC-based workflows for olive oil profiling and suggest the potential applicability of targeted headspace applications in quality control, classification, and sensory characterization of VOO.