Journal of the American Oil Chemists' Society

, Volume 79, Issue 2, pp 117–122

Analysis of free and esterified sterols in vegetable oils

Authors

    • Faculty of Agricultural and Applied Biological SciencesDepartment of Organic Chemistry
  • M. Forcades
    • Faculty of Agricultural and Applied Biological SciencesDepartment of Organic Chemistry
  • R. Verhe
    • Faculty of Agricultural and Applied Biological SciencesDepartment of Organic Chemistry
  • K. Dewettinck
    • Department of Food Technology and Nutrition
  • A. Huyghebaert
    • Department of Food Technology and Nutrition
  • W. De Greyt
    • De Smet Engineering
Article

DOI: 10.1007/s11746-002-0444-3

Cite this article as:
Verleyen, T., Forcades, M., Verhe, R. et al. J Amer Oil Chem Soc (2002) 79: 117. doi:10.1007/s11746-002-0444-3

Abstract

In vegetable oils, phytosterols occur as free sterols or as steryl esters. Few analytical methods report the quantification of esterified and free sterols in vegetable oils. In this study, esterified and free sterols were separated by silica gel column chromatography upon elution with n-hexane/ethyl acetate (90∶10 vol/vol) followed by n-hexane/diethyl ether/ethanol (25∶25∶50 by vol). Both fractions were saponified separately and the phytosterol content was quantified by GC. The analytical method for the analysis of esterified and free sterols had a relative standard deviation of 1.16% and an accuracy of 93.6–94.1%, which was comparable to the reference method for the total sterol analysis. A large variation in the content and distribution of the sterol fraction between different vegetable oils can be observed. Corn and rapeseed oils were very rich in phytosterols, which mainly occurred as steryl esters (56–60%), whereas the majority of the other vegetable oils (soybean, sunflower, palm oil, etc.) contained a much lower esterified sterol content (25–40%). No difference in the relative proportion of the individual sterols among crude and refined vegetable oils was observed.

Key Words

Analysisesterified sterolsfree sterolsgas chromatographyvegetable oils

Copyright information

© AOCS Press 2002