Identification and estimation of tocotrienols in the annatto lipid fraction by gas chromatography mass spectrometry

The lipid fraction of annatto (Bixa orellana L.) seeds was extracted with a Soxhlet apparatus with n-hexane and isolated by thin-layer chromatography. The fatty-soluble antioxidant fraction contained only tocotrienols, mainly delta-tocotrienol, but no tocopherols. The presence of tocotrienols was confirmed by gas chromatography-mass spectrometry. The quantities of delta-tocotrienol were 140-147 mg/100 g dry seeds and 5.2-5.5% wt/wt of lipid extract, determined by gas chromatography and high-performance liquid chromatography, respectively. Currently no vegetable species seems to contain comparable concentrations of delta-tocotrienol.