Fast Ingredient Analysis of Edible Oils Using a Portable Raman Spectrometer

Importance of the Topic

Edible oils serve as essential nutritional components and industrial raw materials. Plant oils are gaining attention due to their high content in mono- and polyunsaturated fatty acids, which offer health benefits and stability in food applications.

Objectives and Study Overview

This application note examines the use of a portable Raman spectrometer coupled with multivariate analysis software to rapidly determine concentrations of oleic, linoleic, mono- and polyunsaturated, and saturated fatty acids in olive, camellia, peanut, sunflower seed, and rapeseed oils at-line.

Methodology and Used Instrumentation

A portable Raman spectrometer with 785 nm excitation and a 10 mm path length liquid cuvette was employed. Spectral preprocessing including background subtraction and Savitzky–Golay smoothing was applied, followed by partial least squares regression using dedicated chemometric software for model construction and prediction.

Main Results and Discussion

Quantitative models demonstrated high correlation coefficients (0.95 to 0.98 for oleic, linoleic, mono- and polyunsaturated acids; 0.84 for saturated acids) and acceptable prediction errors (RMSEP ranging from 0.15 to 0.24). An outlier sample affecting the saturated fatty acid model was identified and removed to improve accuracy.

Benefits and Practical Applications

The method delivers rapid, nondestructive analysis with minimal sample preparation in field or process environments. It supports quality control efforts by enabling timely monitoring of oil composition and lipid oxidation.

Future Trends and Opportunities

Advances in portable spectroscopy and chemometrics will further streamline in situ analysis. Integration with process analytical technology and enhanced algorithms may expand applications to broader food matrix monitoring and real-time quality assurance.

Conclusion

The combination of portable Raman spectroscopy and multivariate analysis provides a viable at-line solution for fast, accurate determination of edible oil ingredients, matching conventional laboratory techniques while reducing analysis time and resource requirements.

References

• Bernuy B, Meuren M, et al. Determination by Fourier Transform Raman Spectroscopy of Conjugated Linoleic Acid in Photoisomerized Soybean Oil. J Agric Food Chem. 2009;57(15):6524–6527.
• Muik B, Lendl B, Molina-Diaz A. Direct monitoring of lipid oxidation in edible oils by Fourier Transform Raman Spectroscopy. Chem Phys Lipids. 2005;2:doi:10.1016/j.chemphyslip.2005.01.003.
• BWIQ chemometrics software. B&W Tek; application overview.
• B&W Tek Shanghai, Central South University, ChemSolve Ltd. Application Note 20120710C.