Analysis of Functional components in coffee

Significance of the topic

Profiling key functional components in coffee supports product quality control, consistency and health assessment. Accurate measurement of alkaloids, phenolics and polar metabolites helps producers and researchers monitor roasting effects, optimize extraction and verify authenticity.

Objectives and overview

This study demonstrates a reversed-phase liquid chromatography method using C18 and pentafluorophenyl phases to separate five representative coffee constituents: trigonelline, pyrocatechol, chlorogenic acid, caffeine and caffeic acid. The aim is to compare retention behavior and resolution on two column chemistries under a unified gradient.

Methodology and instrumentation

The analysis was carried out on a Nexera lite UHPLC system.

• Columns evaluated
  – C18 phase, 150 mm length x 4.6 mm ID, 3 μm particle size
  – Pentafluorophenyl phase, same dimensions and particle size
• Mobile phases
  – A: 20 mmol per L sodium phosphate buffer, pH 2.6
  – B: acetonitrile
• Gradient program
  – 0% B hold 1.00 min; ramp to 10% B at 4.00 min; 20% B at 10.00–12.00 min; increase to 70% B at 12.01–13.00 min; reequilibrate to 0% B by 18.00 min
• Operating conditions
  – Column temperature 25 degC; injection volume 5 μL; mixer volume 180 μL
• Detection
  – Photodiode array at 270 nm and 325 nm

Key results and discussion

Both columns achieved baseline separation of the five analytes at 10 mg per L, but selectivity differed. The PFPP phase improved retention of polar trigonelline and pyrocatechol, while C18 provided sharper peaks for hydrophobic caffeine and caffeic acid. Chlorogenic acid was well resolved on both phases. Peak symmetry and reproducibility met industry requirements.

Benefits and practical applications

The dual‐column approach offers flexibility for routine coffee analysis. Laboratories can select the C18 phase for faster throughput of hydrophobic targets or the PFPP phase to enhance separation of polar components. The method supports quality assurance in roasting, formulation of functional beverages and authentication studies.

Future trends and opportunities

Advances may include coupling this method with high‐resolution mass spectrometry for structural confirmation and quantitation of minor phenolic derivatives. Miniaturized flow cells and core shell particles could further reduce analysis time and solvent consumption. Integration with chemometric tools will accelerate fingerprinting and origin determination.

Conclusion

A robust gradient LC method on C18 and PFPP columns enables comprehensive analysis of five key coffee compounds. The approach balances resolution and runtime, offering adaptable workflows for research and industrial laboratories.

References

• Application News an 01-00280, Shimadzu Corporation, First Edition August 2023