Fingerprinting of Green Arabica Coffee Volatile Organic Compounds (VOCs): HS-GC-IMS Versus GC × GC-MS

Area of Science:

• Analytical Chemistry
• Food Science
• Agricultural Science

Background:

• Volatile organic compounds (VOCs) significantly influence coffee aroma and quality.
• Authenticating the geographical origin of green coffee beans is crucial for quality control and preventing fraud.
• Nontargeted analytical techniques are valuable for comprehensive chemical profiling.

Purpose of the Study:

• To compare the efficacy of HS-GC-IMS and GC×GC-MS for fingerprinting VOCs in green *Coffea arabica* beans.
• To determine the ability of these techniques to differentiate coffee beans based on geographical origin.
• To identify key VOCs contributing to interorigin variability.

Main Methods:

• Nontargeted analysis of volatile organic compounds (VOCs) using headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS).
• Nontargeted analysis of VOCs using comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC-MS).
• Chemometric analyses including principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and hierarchical clustering.

Main Results:

• HS-GC-IMS rapidly differentiated coffee samples by origin, clustering them effectively.
• GC×GC-MS identified 98 compounds, including methoxypyrazines, aldehydes, and alcohols, crucial for origin differentiation.
• Both methods, supported by PCA and PLS-DA, successfully distinguished geographical origins, revealing region-specific VOC patterns.

Conclusions:

• HS-GC-IMS is efficient for high-throughput screening of green coffee beans for origin authentication.
• GC×GC-MS provides detailed molecular insights into aroma precursors and aids in origin differentiation.
• The complementary use of HS-GC-IMS and GC×GC-MS enhances green coffee authentication and quality control strategies.