Determination of Fatty Acid Methyl Esters in Edible Argan Oil

Importance of the Topic

Edible oils are widely consumed and their fatty acid composition influences nutritional and quality attributes. Accurate profiling of fatty acid methyl esters in oils such as argan oil is essential for quality control, authentication, and nutritional assessment. The determination of cis- and trans-isomers and omega fatty acids supports regulatory compliance and consumer health interests.

Objectives and Study Overview

This study demonstrates a GC-FID method for quantifying 37 FAMEs in culinary argan oil following ISO-12966 guidelines. Six commercially sourced argan oil samples were analyzed to assess compositional variability and quality indicators among different brands.

Methodology

A base esterification procedure was applied to convert triglycerides into FAMEs, with a C4–C24:1 multicomponent reference standard diluted in hexane. Analytical separation employed a capillary gas chromatograph with flame ionization detection. Key chromatographic conditions included a long polar column, helium carrier gas flow at 2.4 mL/min, and a temperature program from 100°C to 240°C in controlled ramps.

Instrumentation

• Gas chromatograph: SCION 456 GC with FID detector
• Column: Rt-2560, 100 m × 0.25 mm × 0.20 µm
• Injector: 240°C, split ratio 1:10
• Carrier gas: helium at 2.4 mL/min
• Detector: flame ionization at 260°C
• Software: CompassCDS for automated peak identification and data processing

Main Results and Discussion

Complete resolution of all 37 FAME components was achieved. Automated alignment with the reference standard allowed rapid identification. Among six samples, two oils from the same manufacturer showed identical profiles. All samples contained significant monounsaturated (omega-9) and polyunsaturated (omega-3 and omega-6) FAMEs, with no trans fats detected.
Normalized composition revealed that five oils had total unsaturated FAME content ranging from 72% to 78%, close to the typical 80% benchmark for high-quality argan oil. One sample exhibited a lower unsaturation level of 61%, indicating variable product quality in the market.

Benefits and Practical Applications

• Provides a rapid, robust method for comprehensive FAME profiling in edible oils
• Supports quality control and authentication of argan oil products
• Automated data processing streamlines laboratory workflows
• Enables nutritional labeling and regulatory compliance

Future Trends and Potential Applications

Advances may include coupling GC-FID with mass spectrometry for enhanced isomer discrimination and lower detection limits. Miniaturized and portable GC systems could facilitate on-site oil authentication. Integration with chemometric analysis and AI-driven data interpretation will further improve sample classification and quality prediction.

Conclusion

The developed GC-FID protocol enables complete separation and quantification of 37 FAMEs in edible argan oil, demonstrating its effectiveness for routine quality assessment. The observed variability among commercial samples underscores the importance of detailed fatty acid profiling for ensuring product authenticity and nutritional value.

References

• Ascension Reuda et al. Characterization of fatty acid profile of Argan Oil and other edible vegetable oils by Gas Chromatography and discriminant analysis. Journal of Chemistry, 2014.