Supercritical fluid carbon dioxide extraction of annatto seeds and quantification of trans-bixin by high pressure liquid chromatography

Bixin, a pigment used for food colouring is known to have a hyperglycemic effect. It was extracted using supercritical carbon dioxide, from the seeds of annatto (Bixa orellana L.). The major pigment in annotto, trans-bixin, was quantified by high pressure liquid chromatography. A combination of static and dynamic modes of extraction with carbon dioxide containing acetonitrile (0.05% trifluoroacetic acid) as modifier at 60.62 MPa and 40°C was found to the best set of conditions studied and afforded 2.70 mg bixin/g dry weight of the annatto seeds.