Characterisation of whiskeys using solid-phase microextraction with gas chromatography-mass spectrometry

Area of Science:

• Analytical Chemistry
• Food Science
• Distillation and Fermentation

Background:

• Flavor volatile analysis is crucial for characterizing spirits like whiskey.
• Existing methods may lack the sensitivity or efficiency for comprehensive volatile profiling.
• Understanding the volatile composition of Irish and Scottish whiskeys can inform quality control and authenticity assessments.

Purpose of the Study:

• To develop and validate a method for the detection, identification, and quantification of flavor volatiles in whiskeys.
• To characterize the unique volatile profiles of Irish and Scottish whiskeys.
• To optimize parameters for solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS).

Main Methods:

• Solid-phase microextraction (SPME) using an 85 µm poly(acrylate) fiber was employed for volatile extraction.
• Gas chromatography-mass spectrometry (GC-MS) was utilized for the separation and identification of volatile compounds.
• Method validation included optimizing extraction time, sample volume, desorption time, and assessing the impact of salt.

Main Results:

• A method was established to characterize 17 key flavor congeners, including fusel alcohols, acetates, and esters.
• Optimal extraction conditions were determined: 35 min extraction, 3 ml sample volume, and 5 min desorption.
• Characteristic volatile profiles were obtained for different whiskeys, with high linearity (0.993-0.999) and defined detection limits (0.1-21 mg/l).

Conclusions:

• The developed SPME-GC-MS method provides a robust and sensitive approach for analyzing whiskey volatiles.
• The study successfully identified and quantified key flavor compounds, enabling distinct profiling of Irish and Scottish whiskeys.
• This validated methodology can be applied to quality assessment and comparative studies of distilled spirits.