Skip to main content
SpringerLink
Log in

Determination of olive oil free fatty acid by fourier transform infrared spectroscopy

  • Published:
Journal of the American Oil Chemists' Society

Abstract

A new procedure for determining free fatty acids (FFA) in olive oil based on spectroscopic Fourier transform infrared-attenuated total reflectance spectroscopy measurements is proposed. The range of FFA contents of samples was extended by adding oleic acid to several virgin and pure olive oils, from 0.1 to 2.1%. Calibration models were constructed using partial least-squares regression (PLSR). Two wavenumber ranges (1775–1689 cm−1 and 1480–1050 cm−1) and several pretreatments [first and second derivative; standard normal variate (SNV)] were tested. To obtain good results, splitting of the calibration range into two concentration intervals (0.1 to 0.5% and 0.5 to 2.1%) was needed. The use of SNV as a pretreatment allows one to analyze samples of different origins. The best results were those obtained in the 1775–1689 cm−1 range, using 3 PLSR components. In both concentration ranges, at a confidence interval of α = 0.05, no significant differences between the reference values and the calculated values were observed. Reliability of the calibration vs. stressed oil samples was tested, obtaining satisfactory results. The developed method was rapid, with a total analysis time of 5 min; it is environment-friendly, and it is applicable to samples of different categories (extra virgin, virgin, pure, and pomace oil).

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Commission Regulation (EEC), No 2568/91, OJ No L 248, 5.9, 1991, pp. 1–83

  2. Lai, Y.W., E.K. Kemsley, and R.H. Wilson, Quantitative Analysis of Potential Adulterants of Extra Virgin Olive Oil Using Infrared Spectroscopy, Food Chem. 53:95–98 (1995).

    Article  CAS  Google Scholar 

  3. Bewig, K.M., A.D. Clarke, C. Roberts, and N. Unklesbay, Discriminant Analysis of Vegetable Oils by Near-Infrared Reflectance Spectroscopy, J. Am. Oil Chem. Soc. 71:195–200 (1994).

    Article  CAS  Google Scholar 

  4. Tsimidou, M., and K.X. Karakostas, Geographical Classification of Greek Virgin Olive Oil by Non-Parametric Multivariate Evaluation of Fatty Acids Composition, J. Sci. Food Agric. 62:253–257 (1993).

    Article  CAS  Google Scholar 

  5. van de Voort, F.R., A.A. Ismail, J. Sedman, and G. Emo, Monitoring the Oxidation of Edible Oils by Fourier Transform Infrared Spectroscopy, J. Am. Oil Chem. Soc. 71:243–253 (1994).

    Article  Google Scholar 

  6. van de Voort, F.R., A.A. Ismail, and J.A. Sedman, A Rapid, Automated Method for the Determination of cis- and trans-Content of Fats and Oils by Fourier Transform Infrared Spectroscopy, Ibid.:873–880 (1995).

    Article  Google Scholar 

  7. van de Voort, F.R., A.A. Ismail, J. Sedman, J. Dubois, and T. Nicodemo, The Determination of Peroxide Value by Fourier Transform Infrared Spectroscopy, Ibid.:921–926 (1994).

    Article  Google Scholar 

  8. Ismail, A.A., F.R. van de Voort, G. Emo, and J. Sedman, Rapid Quantitative Determination of Free Fatty Acids in Fats and Oils by Fourier Transform Infrared Spectroscopy, Ibid.:335–341 (1993).

    Article  CAS  Google Scholar 

  9. Blanco, M., J. Coello, H. Iturriaga, S. Maspoch, and C. de la Pezuela, Quantitation of the Active Compound and Major Excipients in a Pharmaceutical Formulation by Near Infared Diffuse Reflectance Spectroscopy with Fibre Optical Probe, Anal. Chim. Acta 333:147–156 (1996).

    Article  CAS  Google Scholar 

  10. Blanco, M., J. Coello, H. Iturriaga, S. Maspoch, and C. de la Pezuela, Strategies for Constructing the Calibration Set in the Determination of Active Principles in Pharmaceuticals by Near Infrared Diffuse Reflectance Spectrometry, Analyst 122:761–765 (1997).

    Article  CAS  Google Scholar 

  11. Comission Regulation (EEC), No 2568/91, OJ No L. 248, 5.9, 1991 pp. 6–7.

  12. Barnes, R.J., M.S. Dhanoa, and S.J. Lister, Standard Normal Variate Transformation and De-Trending of Near-Infrared Diffuse Reflectance Spectra, Appl. Spectrosc. 43:772–777 (1989).

    Article  CAS  Google Scholar 

  13. Dhanoa, M.S., S.J. Lister, R. Sanderson, and R.J. Barnes, The Link Between Multiplicative Scatter Correction (MSC) and Standard Normal Variate (SNV) Transformations of NIR Spectra, J. Near Infrared Spectrosc. 2:43–47 (1994).

    CAS  Google Scholar 

  14. Martens, H., and T. Naes, Multivariate Calibration. Wiley, New York (1989).

    MATH  Google Scholar 

  15. Geladi, P., and B.R. Kowalski, Partial Least Squares Regression: A Tutorial, Anal. Chim. Acta 185:1–17 (1986).

    Article  CAS  Google Scholar 

  16. Wold, S., Cross Validatory Estimation of the Number of Components in Factor and Principal Component Models, Technometrics 20:397–406 (1978).

    Article  MATH  Google Scholar 

  17. Naes, T., The Design of Calibration in Near-Infrared Reflectance by Clustering, J. Chemom. 1:121–134 (1987).

    Article  CAS  Google Scholar 

  18. International Standards Organisation, Statistical Interpretation of Test Results—Estimation of the Mean-Confidence Interval, ISO 2602-1980 (E) (1980), pp. 1–5.

  19. Naes, T., and T. Isaksson, Splitting of Calibration Data by Cluster Analysis, J. Chemom. 5:49–65 (1991).

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Unitat de Química Analítica, Departament de Química, Edifici CN, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Barcelona, Spain

    Enriqueta Bertran, Marcelo Blanco, Jordi Coello, Hortensia Iturriaga, Santiago Maspoch & Ivan Montoliu

Authors
  1. Enriqueta Bertran
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Marcelo Blanco
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jordi Coello
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Hortensia Iturriaga
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Santiago Maspoch
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Ivan Montoliu
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Hortensia Iturriaga.

About this article

Cite this article

Bertran, E., Blanco, M., Coello, J. et al. Determination of olive oil free fatty acid by fourier transform infrared spectroscopy. J Amer Oil Chem Soc 76, 611–616 (1999). https://doi.org/10.1007/s11746-999-0011-9

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11746-999-0011-9

Key Words

Search

Navigation