Bixin is an

apocarotenoid Apocarotenoids are organic compounds which occur widely in living organisms. They are derived from carotenoids by oxidative cleavage, catalyzed by carotenoid oxygenases. Examples include the vitamin A retinoids retinal, retinoic acid, and retinol; a ...

found in the seeds of the achiote tree (''Bixa orellana'') from which it derives its name. It is commonly extracted from the seeds to form

annatto Annatto ( or ) is an orange-red condiment and food coloring derived from the seeds of the achiote tree (''Bixa orellana''), native to tropical America. It is often used to impart a yellow or orange color to foods, but sometimes also for its flav ...

, a natural

food coloring Food coloring, or color additive, is any dye, pigment, or substance that imparts color when it is added to food or drink. They come in many forms consisting of liquids, powders, gels, and pastes. Food coloring is used in both commercial food ...

, containing about 5% pigments of which 70-80% are bixin.

Applications

: center, red seeds of the achiote tree : left, Bixin is one of the colorants used in the snack Cheetos. Several thousand tons are harvested annually.

Chemical properties

Bixin is unstable. It isomerizes into ''trans''-bixin (β-bixin), the double-bond isomer. : Trans-bixin

Bixin is soluble in fats and

alcohols In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl () functional group bound to a saturated carbon atom. The term ''alcohol'' originally referred to the primary alcohol ethanol (ethyl alcohol), which is ...

but insoluble in water. Upon exposure to

alkali In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a ...

, the

methyl In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many ...

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...

hydrolyzed Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis ...

to produce the

dicarboxylic acid In organic chemistry, a dicarboxylic acid is an organic compound containing two carboxyl groups (). The general molecular formula for dicarboxylic acids can be written as , where R can be aliphatic or aromatic. In general, dicarboxylic acids show ...

norbixin, a water-soluble derivative. : norbixin structure

References

{{carotenoids Apocarotenoids E-number additives