Bixin is an apocarotenoid found in the seeds of the achiote tree (Bixa orellana)[1] from which it derives its name. It is commonly extracted from the seeds to form annatto, a natural food coloring, containing about 5% pigments of which 70–80% are bixin.[2]
thumb|center|Red seeds of the achiote tree
thumb|Bixin is one of the colorants used in the snack Cheetos.Several thousand tons are harvested annually.[3]
Bixin is unstable. It isomerizes into trans-bixin (β-bixin), the double-bond isomer.
Bixin is soluble in fats and alcohols but insoluble in water. Upon exposure to alkali, the methyl ester is hydrolyzed to produce the dicarboxylic acid norbixin, a water-soluble derivative.