Botanical Source -
Annatto seeds, immersed in vegetable oil at a temperature not exceeding 70°C, are mechanically abraded to remove the pericarp
from the seeds. The slurry of the pigment in oil is heated under vacuum of about 20 mm Hg at a temperature not exceeding 130°C. The solution is filtered to remove
oil-soluble annatto coloursexhibit different shades
ranging from yellow to orange-red.
Dissolution of bixin in oil changes the colour from orange to yellow.