A LC-ESI-Q-TOF Method for Identification and Relative Composition Analysis of Triacylglycerols in Tropical Oil - (3) Moringa Oleifera Seed Oil

Significance of the Topic

Triacylglycerol profiling in Moringa oleifera seed oil is critical because the fatty acid composition underpins nutritional value, stability, and functional applications in food, cosmetics, and pharmaceuticals.
Conventional GC-FID methods require hydrolysis and derivatization, whereas direct LC-MS analysis offers faster, more sensitive detection of intact TAG species.

Study Objectives and Overview

• Develop and apply a rapid LC-ESI-Q-TOF method for direct identification of TAGs in M. oleifera seed oil.
• Characterize relative compositions of TAG species across different oil samples (M0–M3).
• Validate consistency and reproducibility of TAG profiles among batches.

Methodology and Sample Preparation

Oil samples were diluted in a chloroform–acetone mixture and further diluted in mobile phase B to 600 ppm.
LC separation employed a Shim-pack Velox C18 column (2.1×100 mm, 2.7 µm) at 0.4 mL/min with a gradient of 20 mM ammonium formate in water (A) and 2-propanol/acetonitrile (80:20, B).
The column oven was maintained at 45 °C and injection volume was 1 µL.

Used Instrumentation

• Shimadzu LCMS-9030 Q-TOF mass spectrometer with heated ESI interface.
• Shim-pack Velox C18 column (2.1×100 mm, 2.7 µm).
• Data acquisition in positive ion TOF mode (m/z 700–1200) and targeted MS/MS of up to 31 precursors.

Main Results and Discussion

A total of 33 TAGs were identified based on accurate mass and MS/MS fragmentation.
Triolein (OOO) emerged as the predominant species (39.7% area).
Other abundant TAGs included OOP, OOS, OOA, OOB, OOLi and OOG (ECN 48–56).
Distribution across samples showed ∼2.1% TAGs with one MUFA (DB=1), ∼42.5% with two MUFAs or one PUFA (DB=2), and ∼50.6% with three or more double bonds (DB≥3).
Retention time shifts correlated with equivalent carbon number, reflecting oil’s high oleic acid content (~70%).

Benefits and Practical Applications

• Rapid, direct profiling of intact TAGs without derivatization.
• High sensitivity and reproducibility for quality control in oil production.
• Detailed composition data supports nutritional labeling and authenticity testing.

Future Trends and Potential Applications

• Integration with supercritical fluid chromatography (SFC) for faster separations.
• Implementation of ion mobility spectrometry to resolve isomeric TAGs.
• Automation and AI-driven data analysis for high-throughput screening.
• Extending the method to other valuable tropical oils and complex food matrices.

Conclusion

The established LC-ESI-Q-TOF workflow enables comprehensive, high-fidelity characterization of TAG profiles in Moringa seed oil, confirming its high oleic acid content and consistent batch-to-batch composition. This approach enhances quality assurance and supports further functional and nutritional studies.

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