New trends in determining the authenticity of corn oil

HPLC analysis of triacylglycerols and minor components, such as free and ac ylated sterols, and sterylglycosides, tocopherols and isoprenoid alcohols, have been employed for establishing oil authenticity. GLC analysis of the w hole sterols as their TMS derivatives has been also conducted. Genuine oils, namely, rapeseed, sunflower and corn oil as well as corn oil admixtures with the two oils were analyzed. Triacylglycerols and tocopherols were directly determined in the oils where as the four sterol in lipids (free and acylated sterols and sterylglycoside s) and isoprenoid alcohols were isolated and derivatized into their anthroy l nitrile derivatives. It was concluded that the analysis of minor components in combination with triacylglycerols is more advantageous for authentication of corn oil. Howev er, isoprenoid alcohols are more decisive in this respect. Natural variability of the components in the oils from different origins ca n modify the detection limits.