Canthaxanthin

Canthaxanthin /ˌkænθəˈzænθɪn/ (About this soundlisten) is a keto-carotenoid[3] pigment widely distributed in nature. Carotenoids belong to a larger class of phytochemicals known as terpenoids. The chemical formula of canthaxanthin is C40H52O2.[4] It was first isolated in edible mushrooms. It has also been found in green algae, bacteria, crustaceans, and bioaccumulates in fish such as carp, golden grey mullet, seabream and trush wrasse.[4]

Canthaxanthin is associated with E number E161g and is approved for use as a food coloring agent in different countries, including the United States[5] and the EU;[6] however, it is not approved for use in Australia and New Zealand.[7] It is generally authorized for feed applications in at least the following countries: US,[8] Canada,[9] EU.[10] In the EU, canthaxanthin is allowed by law to be added to trout feed, salmon feed and poultry feed.[11] The European Union limit is 80 mg/kg of feedstuffs,[4] 8 mg/kg in feed for egg laying hens and 25 mg/kg in feed for other poultry and salmonids.

Canthaxanthin is a potent lipid-soluble antioxidant.[12][13] The biological functions of canthaxanthin are related, at least in part, to its ability to function as an antioxidant (free radical scavenging/vitamin E sparing) in animal tissues.[14]