Identification of new steroidal hydrocarbons in refined oils and the role of hydroxy sterols as possible precursors

The dehydration of sterols during the refining process of vegetable oils re sults in the formation of steroidal hydrocarbons (sterenes or steradienes) with two double bonds in the ring system. Other steroidal hydrocarbons whos e structures were in agreement with the presence of three double bonds in t he ring system were detected in the sterene fractions of refined vegetable oils. The 5 alpha-, 7 alpha-, and 7 beta-hydroxy derivatives of cholesterol and phytosterols have been dehydrated in n-butanol/H3PO4 to form steroidal hydrocarbons with three double bonds at the 2, 4, and 6 positions in the r ing system. These hydrocarbons had the same relative retention time and mas s spectra as those present in the sterene fractions of refined oils. The de hydration of the hydroxy sterols dissolved in extra virgin olive oil and in the presence of 1% bleaching earths at 80 degrees C for 1 h results in the formation of the same steroidal hydrocarbons found in the refined oils.