Abstract
Free sterols were prepared from a pure butter supplied from the National Institute of Animal Industry and six ordinary commercial butters. Steryl fraction dissolved in acetone was applied to Shimadzu GC-1B apparatus with hydrogen flame ionization detector. The glass column used was 4mm in diameter and 150cm in length and was packed with 1.5% SE-30 on silanized Chromosorb W 60/80. The column temperature was 235° and the flow rate of nitrogen gas 90ml/min, with the separated sterols being detected at 245°.
From the butter samples which had been confirmed to be negative to the phytosteryl acetate test, no phytosteryl peaks or only that of stigmasterol peaks were detected, on the contrary, three peaks corresponding to campesterol, stigmasterol and β-sitosterol were detected from the butter samples proved to be positive to the phytosteryl acetate test.
It can be concluded that a pure butter sample may contain stigmasterol in minute quantity as the essential component. When either campesterol or β-sitosterol was detected from a sample, the butter will be thought to have been adulted with vegetable fat and oil.
