Structural Modifications of 4,4′‐Dimethyl Sterols during the Hydrogenation of Edible Vegetable Oils

The structural changes induced by the hydrogenation of dietary vegetable oils affect not only fatty acids but sterolic components too, especially C‐24‐methylene and C‐24‐ethylidene sterols. The main alterations found in the triterpene alcohols involve 24‐methylene‐cycloartenol and, to a lesser extent, cycloartenol. Of the three potential hydrogenation‐induced reactions to affect these compounds, i. e. hydrogenation of the double ethylene bonds, the opening of the cyclopropane ring and the isomerization of the double bonds in the side chain, the latter is predominant. Cyclobranol and cyclosadol from 24‐methylene cycloartanol and 9β,19‐cyclo‐5α‐lanost‐25‐en‐3β‐ol from cycloartenol account for most of the structural isomers formed.