METABOLOMICS APPROACHES POWERFUL TOOLS FOR ANALYSING THE QUALITY OF RAW MATERIALS VETIVER ESSENTIAL OIL A CASE STUDY

Metabolomics Approaches as Powerful Tools for Analyzing the Quality of Raw Materials: A Case Study on Vetiver Essential Oil

Importance of the Topic
The fragrance industry relies heavily on vetiver essential oil derived from Chrysopogon zizanioides. Its complex earthy, woody and smoky notes are highly valued, yet natural variability and evolving regulations on natural complex substances demand deeper chemical insight. Untargeted metabolomic profiling provides a comprehensive strategy to assess quality, detect contamination and authenticate botanical origin.
Objectives and Study Overview
This study applied an untargeted metabolomic workflow to ten vetiver oil samples from Haiti, Indonesia and Paraguay. Key aims were:

• To map the full chemical fingerprint of each origin.
• To discriminate geographical groups and reveal outlier samples.
• To identify markers of contamination or non-conformity.

Methodology and Instrumentation
The analysis combined complementary chromatographic techniques and ionization modes:

• UPLC: ACQUITY UPLC with CORTECS C18 column; gradient from aqueous ammonium formate to methanol/acetonitrile.
• UPC²: ACQUITY UPC² with supercritical CO₂ and MeOH/ACN modifier on HSS SB C18 column.
• Mass Spectrometry: Xevo G2 QToF in MSE data-independent acquisition; ESI and APCI sources at positive/negative polarities; ASAP probe for rapid screening.
• Data Processing: Progenesis QI v2.3 with an in-house database of 400 vetiver compounds; statistical analyses via PCA, HCA, PLS-DA and OPLS-DA.

Main Results and Discussion

• Complementary LC-MS profiles provided richer chemical coverage than single techniques.
• PCA and HCA clustered samples by origin, confirming distinct chemical signatures; Indonesian oils showed outliers.
• Supervised PLS-DA and OPLS-DA improved class separation and highlighted discriminant features.
• A key marker at RT 11.43 min, m/z 298.2502 Da was identified as ricinoleic acid, indicating contamination in certain Indonesian batches.
• ASAP probe enabled a rapid 5-minute fingerprint assay to flag non-conforming samples early in quality control.

Benefits and Practical Applications
The proposed workflow supports:

• Comprehensive quality control of essential oils beyond volatile profiling.
• Early detection of contaminants undetectable by conventional GC-MS.
• Authentication of botanical origin to prevent adulteration.
• Rapid screening protocols to improve laboratory throughput.

Future Trends and Opportunities
Advances may include:

• Integration with metabolomic databases and machine-learning algorithms for automated marker discovery.
• Miniaturized or portable high-resolution instruments for on-site testing.
• Expansion to other natural product matrices and regulated commodities.
• Standardization of metabolomic workflows for industry-wide quality assurance.

Conclusion
An untargeted metabolomic strategy combining UPLC, UPC² and high-resolution MS, supported by multivariate statistics, offers a powerful, rapid and robust approach to assess vetiver essential oil quality and origin. This methodology complements established GC-based techniques, enhances contamination detection and strengthens raw material authentication.
Reference
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