Formation of a Delta(7) triterpene alcohol in refined olive oils

The triterpene alcohol fraction in several virgin olive oils and the corres ponding oils refined by alkali and by physical processes was analyzed by ga s chromatography. A Delta(7) compound was detected in all refined olive oil s but not in virgin olive oils. This compound was tentatively identified by gas chromatography-mass spectrometry as 24-methyl-5 alpha-lanosta-7,24-die n-3 beta-ol, a 24-methylenecycloartanol isomer produced during the refining process by the opening of the 9,19 cyclopropane ring with formation of a d ouble bond in the Delta(7) position and the translocation of a double bond in the side chain from the 24-28 to the 24-25 position. Paper no. J9213 in JAOCS 76, 1421-1423 (December 1999).