On sample preparation methods for fermented beverage VOCs profiling by GCxGC-TOFMS

Area of Science:

• Analytical Chemistry
• Food Science
• Metabolomics

Background:

• Aromas and tastes significantly impact fermented beverage quality.
• Accurate determination of aromatic compounds requires comprehensive profiling of volatile organic compounds (VOCs).
• Existing VOC profiling methods are sensitive to the chosen sample collection technique.

Purpose of the Study:

• To evaluate the impact of different sample preparation techniques on VOC profiling in fermented beverages.
• To identify the most suitable sample preparation protocol for comprehensive VOC analysis.
• To compare dynamic headspace (DHS), vortex-assisted liquid-liquid microextraction (VALLME), multiple stir bar sorptive extraction (mSBSE), solid phase extraction (SPE), and solid phase micro-extraction (SPME).

Main Methods:

• Five distinct sample preparation methods were applied to beer, cider, red wine, and white wine.
• Collected VOCs were analyzed using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS).
• Optimization of GCxGC oven parameters was performed using the Box-Behnken response surface model.

Main Results:

• Significant variations in VOC profiling results were observed across different sample preparation methods.
• Commonly identified VOCs represented a small portion of the total annotated compounds.
• Optimal coverage for specific fermented beverages was achieved with combined methods: SPME and SPE for beer, and VALLME for wine and cider.

Conclusions:

• GCxGC-TOFMS is a powerful tool for non-targeted VOC profiling in fermented beverages, but requires robust data processing protocols.
• Each sample preparation technique yields a unique VOC profiling spectrum.
• Combining complementary sample preparation methods enhances the coverage of the VOC metabolome.