Analytical techniques for determination of mycotoxins in barley, malt and beer: A review

Significance of the Topic

Mycotoxins are toxic secondary metabolites produced by fungi such as Aspergillus, Fusarium and Penicillium that frequently contaminate cereals, malt and beer, posing acute and chronic health risks to humans and animals. Regulatory bodies worldwide have set strict maximum limits for major mycotoxins (e.g., aflatoxins, ochratoxin A, deoxynivalenol, zearalenone) to ensure food safety and protect consumer health.

Objectives and Study Overview

This review critically evaluates current analytical strategies for the determination of key mycotoxins in barley, malt and beer. It surveys sampling and homogenization approaches, extraction and purification protocols, and the range of instrumental and screening techniques applied in laboratories and industrial quality control.

Methodology and Instrumentation

Sample preparation is highlighted as the major source of variability due to heterogeneous mycotoxin distribution. Common extraction methods include solid–liquid extraction with acetonitrile/water, solid-phase extraction (SPE), immunoaffinity extraction (IAE), QuEChERS (quick, easy, cheap, effective, rugged and safe), salting-out assisted liquid–liquid extraction (SALLE), microwave- and pressurized solvent extraction, supercritical fluid extraction and dispersive liquid–liquid microextraction (DLLME). Purification steps employ immunoaffinity columns (IAC), dispersive SPE with sorbents such as primary–secondary amine (PSA), C18 or graphitized carbon black, molecularly imprinted polymers (MIP), or one-step clean-up materials.

Used Instrumentation

• Liquid chromatography with UV, fluorescence (FLR) or photodiode array (PDA) detection
• Gas chromatography with flame ionization (FID), electron capture (ECD) or mass spectrometric detection (GC–MS, GC–MS/MS)
• Liquid chromatography–tandem mass spectrometry (LC–MS/MS) with electrospray (ESI), atmospheric pressure chemical (APCI) or photo-ionization (APPI)
• Capillary electrophoresis (CE) with UV or fluorescence detection
• Screening platforms: ELISA, immunosensors, near-infrared (NIR), Fourier-transform infrared (FT-IR) and Raman spectroscopy

Main Results and Discussion

• LC–MS/MS in multiple reaction monitoring mode has become the preferred multi-mycotoxin approach, offering simultaneous quantification of dozens of analytes with high sensitivity and selectivity.
• QuEChERS coupled with LC–MS/MS simplifies sample preparation and covers mycotoxins of diverse polarity, but residual matrix effects often necessitate matrix-matched calibration or isotope-dilution strategies.
• Immunoaffinity clean-up delivers excellent specificity for targeted toxins but is limited to one or few compounds per assay.
• Rapid screening methods such as ELISA, biosensors, NIR and Raman spectroscopy facilitate on-site monitoring but require confirmatory chromatography for quantification.

Benefits and Practical Applications of the Method

• Tailored extraction and clean-up protocols maximize recoveries and reduce interferences in complex matrices.
• Hyphenated techniques (e.g., QuEChERS+LC–MS/MS) balance throughput and robustness for routine quality control in malting and brewing laboratories.
• Portable immuno- and optical sensors support rapid decision-making during raw material intake and process control.

Future Trends and Potential Applications

• Development of novel sorbents (nanomaterials, MIP) to streamline clean-up and reduce solvent use.
• Integration of biochips and microarray platforms for high-throughput multiplexed detection.
• Expansion of ambient ionization mass spectrometry and data-driven analytics for real-time, in situ mycotoxin mapping.
• Inclusion of emerging and masked mycotoxins in multi-residue screening panels.

Conclusion

Effective mycotoxin analysis in barley, malt and beer hinges on rigorous sampling, optimized extraction/clean-up and advanced detection techniques. LC–MS/MS combined with simplified sample preparation such as QuEChERS represents the state-of-the-art for simultaneous multi-mycotoxin determination. Continued innovation in sorbent materials, ambient MS and miniaturized sensors will drive faster, greener and more comprehensive monitoring solutions.

References

European Commission. (2006). Regulation (EC) No 1881/2006 setting maximum levels for contaminants in foodstuffs.
Anastassiades, M. et al. (2003). Fast and easy multiresidue method employing acetonitrile extraction and dispersive SPE. Journal of AOAC International, 86(2), 412–431.
Sulyok, M. et al. (2006). Development and validation of an LC–MS/MS method for 39 mycotoxins. Rapid Communications in Mass Spectrometry, 20(18), 2649–2659.
Spanjer, M. C. et al. (2008). LC–MS/MS multi-method for mycotoxins after single extraction. Food Additives and Contaminants, 25(4), 472–489.
Rahmani, A. et al. (2009). Qualitative and quantitative analysis of mycotoxins: A review. Comprehensive Reviews in Food Science and Food Safety, 8(3), 202–251.