Specific case studies looking at authenticity assessment with LC- Q/TOF MS

Significance of Topic

Authenticating food products is essential to protect consumers, guarantee fair trade and preserve brand reputation. Rice and herbs & spices are frequent targets of fraud due to their global demand and complex supply chains. Advanced analytical methods based on high-resolution mass spectrometry enable rapid detection of adulteration and mislabelling, improving food integrity and public health.

Study Objectives and Overview

The work presented by the Institute for Global Food Security (IGFS) focuses on two case studies:

• Developing a comprehensive rice authenticity program combining field screening and laboratory confirmation.
• Establishing a fast workflow for herbs and spices authenticity (exemplified by oregano).

The rice project aims to create a collaborative network, harmonize test methods, and transfer expertise to international partners. The herbs & spices study seeks to accelerate marker discovery and screening through streamlined workflows.

Methodology and Used Instrumentation

The analytical strategy integrates untargeted fingerprinting with chemometrics and targeted MS/MS confirmation:

• Sample Preparation: Automated or semi-automated extraction protocols using aqueous methanol or methanol/water/MTBE mixtures, followed by centrifugation and filtration.
• Separation Techniques: Ultra-performance liquid chromatography (UPLC) in reversed-phase, HILIC and supercritical fluid chromatography (SFC) modes, as well as gas chromatography for volatiles and derivatised metabolites.
• Mass Spectrometry: High-resolution instruments (two LC-QToF systems) and triple quadrupole MS for targeted confirmatory analysis.
• Data Processing: Molecular feature extraction in Qual, statistical modelling in Mass Profiler Professional (MPP) and Progenesis, followed by PLS-DA and OPLS-DA to select species- or quality-specific markers.

Main Results and Discussion

• Rice Proof-of-Concept: Portable NIR screening distinguished vendors; LC-QToF profiling of 850 features enabled unsupervised PCA clustering by variety and quality group, and supervised OPLS-DA identified candidate markers such as OM6976 and IR50404.
• Herbs & Spices Workflow: Oregano fingerprinting by LC-QToF generated dozens of discriminant ions. A rapid 2-minute LC gradient on a guard column preserved marker information while reducing run time fivefold.
• Comparative Analysis: Fast methods retained 88–91% discriminatory power with exclusive markers versus a 10-minute protocol.

Practical Benefits and Applications

These approaches enable:

• On-site rapid screening of rice fraud with portable NIR.
• High-throughput laboratory confirmation using LC-QToF and LC-MS/MS.
• Transferable workflows for international reference laboratories.
• Reduced sample preparation time with semi-automated protocols.
• Cost-effective screening of herbs & spices in industry QA/QC settings.

Future Trends and Opportunities for Use

The next developments will focus on:

• Integration of ambient ionization (REIMS, DESI) for in situ profiling.
• Deployment of cloud-based chemometric platforms for real-time decision support.
• Expansion to other high-value commodities (e.g., coffee, tea, oils).
• Standardization of globally harmonized reference materials and protocols.
• Implementation of machine learning for marker discovery and predictive authentication.

Conclusion

High-resolution mass spectrometry combined with robust chemometric modelling offers a powerful toolkit for food authenticity testing. The IGFS studies demonstrate successful application to rice varieties and oregano, showcasing scalable workflows that balance speed and accuracy. Broad adoption of these methods by industry and regulatory bodies will strengthen food integrity worldwide.

Reference

Chevallier O. Specific case studies looking at authenticity assessment with LC-Q/TOF MS. Institute for Global Food Security; 6 November 2019.