High Speed Analysis of Iso-α-Acids, α-Acids, and Humulinones in Beer and Usage of Multi-Data Report

Significance of the Topic

The analysis of bittering components in beer such as iso-α-acids, α-acids and humulinones is fundamental to quality control, sensory profiling and product consistency in the brewing industry.
Conventional spectrophotometric methods (IBU) can overestimate bitterness due to nonspecific UV absorption at 275 nm, whereas HPLC provides separation-based accuracy.
Implementing high-speed HPLC protocols supports rapid decision-making in production and research, reducing analysis time by over 90 %.

Objectives and Overview of the Study

This study aimed to develop and validate a high-throughput method for the simultaneous quantification of iso-α-acids, α-acids and humulinones in beer using the Nexera XR HPLC system.
Five commercial beers, including an IPA, were analyzed under two sets of conditions: EBC 9.47-compliant and high-speed separation.
Results were compared with IBU measurements by UV-Vis spectrophotometry and data processing automated via the multi-data report function in LabSolutions.

Methodology and Instrumentation

Sample Preparation

• Beer samples were degassed by sonication with 10 µL 1-octanol, centrifuged and supernatant diluted 1:1 with methanol or buffer.
• Standard and calibration solutions were prepared from certified hop extracts, dissolved in acidic methanol and diluted to working concentrations.

Chromatographic Conditions

• EBC 9.47-compliant: Shim-pack GIST C8 column (250×4.6 mm, 5 µm), mobile phases acetonitrile/1% citric acid buffer and methanol, 45 min runtime, UV detection at 270 nm.
• High-speed analysis: Shim-pack Velox C18 column (50×3.0 mm, 1.8 µm), phosphate buffer with EDTA and acetonitrile gradient, 5 min runtime, UV 270 nm.

Instrumentation

• Liquid Chromatograph: Shimadzu Nexera XR
• Columns: Shim-pack GIST C8 and Shim-pack Velox C18
• Detector: UV at 270 nm
• Software: LabSolutions with multi-data report function
• UV-Vis Spectrophotometer: Shimadzu UV-1900i for IBU determination

Main Results and Discussion

Repeatability

• Relative standard deviations of peak areas for standards were ≤ 0.3% (EBC) and ≤ 0.03% (high-speed), confirming excellent system stability.

Quantitative Analysis

• Comparable concentrations of iso-α-acids, α-acids and humulinones were obtained under both methods for all five beers.
• The IPA exhibited the highest levels of bittering components, correlating with its elevated IBU (≈50.5 mg/L).

Recovery and Precision

• Spike-and-recovery tests under high-speed conditions yielded recoveries of 94–115% and RSDs below 3%.

Comparison with IBU

• IBU values by UV-Vis showed agreement with HPLC data but lacked component specificity.

Benefits and Practical Applications

The high-speed HPLC method enables complete analysis in 5 minutes versus 45 minutes, greatly increasing throughput.
Automated multi-data reporting eliminates manual calculations, reduces transcription errors and supports QA/QC workflows.
Separation-based quantification provides accurate profiling of individual bittering compounds for product development and consistency monitoring.

Future Trends and Potential Applications

Integration of HPLC data with brewery information management systems (BIMS) will streamline traceability and process control.
Advances in column technology and microfluidics may further reduce run times and solvent consumption.
Coupling with mass spectrometry or diode-array detection could expand profiling to additional hop-derived and fermentation metabolites.
Machine-learning algorithms applied to chromatographic fingerprints may enable predictive quality analysis and novel beer style classification.

Conclusion

This application note demonstrates that high-speed HPLC on the Nexera XR system accurately quantifies key bittering compounds in beer within 5 minutes, matching the performance of the standard EBC-compliant method.
The approach enhances laboratory efficiency, supports robust quality control and benefits from automated reporting via LabSolutions.

References

1. American Society of Brewing Chemists, ASBC Methods of Analysis, Beer-23
2. European Brewery Convention, ANALYTICA EBC 9.47