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Transesterification and On-Line LC-GC for Determining the Sum of Free and Esterified Sterols in Edible Oils and Fats

✍ Scribed by Biedermann, Maurus ;Grob, Konrad ;Mariani, Carlo

Publisher
John Wiley and Sons
Year
1993
Weight
626 KB
Volume
95
Category
Article
ISSN
0931-5985

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✦ Synopsis

Abstract

A method is proposed to substitute the classical saponification procedure for the determination of the sterols and other minor components in edible oils and fats. Saponification is replaced by transesterification, which liberates sterols and alcohols from esters under mild conditions, but does not form soap hindering the extraction of the neutrals. Triglycerides are turned into fatty acid methyl esters, which are removed by automated LC‐GC. LC also pre‐separates the minor components into classes, e.g., of linear alcohols, triterpenes, methyl sterols, Ξ”5 sterols, and Ξ”7 sterols. Multiple LC‐GC transfer allows obtaining several gas chromatograms from the same injection into LC. Sample preparation takes some 5 min; 10‐25 samples can be analyzed by an LC‐GC instrument, depending on the number of LC fractions transferred to GC per sample.

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