Comparison of Dried Thyme from Different Geographical Locations with GC-TOFMS and Software Tools Designed to Rapidly Determine Similarities and Differences

Significance of the Topic

The aroma composition of botanicals like dried thyme influences product quality, authenticity, and sensory characteristics in flavor, fragrance, and food industries. Non-target profiling using GC-TOFMS captures a broad range of volatile compounds, enabling comprehensive quality control, raw material authentication, and process optimization.

Objectives and Study Overview

This study aimed to compare the chemical profiles of dried thyme from four geographical origins—France, Morocco, Poland, and Spain—using GC-TOFMS and dedicated data analysis software. Key goals included:

• Profiling non-target volatile compounds via headspace SPME-GC-TOFMS
• Applying deconvolution and spectral matching to resolve co-eluting features
• Employing software tools to align and compare analyte trends across sample sets
• Distinguishing characteristic markers related to sample origin

Methodology

Dried thyme samples were prepared in triplicate by placing 50 mg into headspace vials. Samples were incubated at 40 °C for 2 min with agitation, extracted for 5 min using a tri-phase HS-SPME fiber, and analyzed on GC-TOFMS under a 40–250 °C temperature program. A standard alkane mix provided retention index calibration. Data acquisition covered a 35–500 m/z range at 10 spectra/s to support non-target analysis.

Used Instrumentation

• LECO L-PAL3 Autosampler
• Headspace SPME with PDMS/DVB/CWR fiber
• GC: Rxi-5ms column (30 m × 0.25 mm × 0.25 µm)
• Time-of-Flight MS: LECO Pegasus BTX

Main Results and Discussion

Deconvolution enabled the separation of co-eluting compounds such as β-myrcene and 2-pentyl furan, revealing their individual trends across samples. Representative analytes showed distinct origin-related patterns:

• French thyme: elevated esters, carboxylic acids, and alcohols with fruity notes
• Moroccan thyme: rich in terpenes and terpenoids associated with woody aromas
• Polish thyme: higher levels of nitrogen-containing compounds with nutty descriptors
• Spanish thyme: notable camphor and mint-like components

Principal Component Analysis of aligned peak data grouped France and Poland together, while Morocco and Spain formed distinct clusters, demonstrating clear chemical differentiation by origin.

Benefits and Practical Applications

The combined GC-TOFMS and advanced software workflow provides:

• Enhanced quality control and authentication of herbal materials
• Rapid comparison of complex volatile profiles
• Identification of geographical markers for supply chain verification
• Support for flavor and fragrance product development

Future Trends and Opportunities

Ongoing developments may include integrating machine learning for predictive profiling, real-time instrumentation for in-field analysis, portable TOFMS systems, and deeper metabolomic characterizations using high-resolution tools to further refine origin and quality assessments.

Conclusion

This study demonstrates that HS-SPME GC-TOFMS combined with deconvolution and specialized software offers a powerful approach for non-target profiling and origin differentiation of dried thyme. The workflow facilitates rapid, detailed comparison of complex aromatic matrices, supporting quality assurance and product authenticity.