Method development by GC-ECD and HS-SPME-GC-MS for beer volatile analysis

Area of Science:

• Food Science
• Analytical Chemistry
• Sensory Science

Background:

• Off-flavors significantly impact beer quality and consumer acceptance.
• Identifying and quantifying low-level off-flavors is crucial for quality control in the brewing industry.

Purpose of the Study:

• To develop and validate analytical methods for the extraction, identification, and quantification of key off-flavors in Brazilian Pilsner beers.
• To assess the occurrence and perception thresholds of specific off-flavors.

Main Methods:

• Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) for esters.
• Headspace extraction coupled with gas chromatography-electron capture detection (HS-GC-ECD) for vicinal diketones.
• Analysis of ethyl acetate, isoamyl acetate, ethyl hexanoate, and 2,3-butanedione.

Main Results:

• Validated methods successfully quantified target off-flavors at concentrations below sensory detection limits.
• Ethyl acetate: 39.48 ng/mL (RSD 4.2%)
• Isoamyl acetate: 3.88 ng/mL (RSD 3.4%)
• Ethyl hexanoate: 0.61 ng/mL (RSD 3.1%)
• 2,3-butanedione: 0.10 ng/mL (RSD 2.9%)

Conclusions:

• The developed analytical methods are effective for detecting and quantifying high-incidence beer off-flavors.
• The methods provide precise measurements, even at trace levels relevant to sensory perception.
• This research contributes to improved quality control and consistency in Pilsner beer production.