Carotenoid and vitamin A, and metabolism of carotenoids, β-carotene, canthaxanthin, astaxanthin, zeaxanthin, lutein and tunaxanthin in tilapia tilapia nilotica

Abstract

1. 1. Feeding trials were carried out in tilapia with β-carotene, canthaxanthin, astaxanthins [(3R,3′R)-, (3R,3′S; meso)- and (3S,3′S)-astaxanthin diester and a mixture of these three stereoisomers of free astaxanthin], (3R,3′R)-zeaxanthin, lutein A and tunaxanthin (a mixture of tunaxanthins A and F). 2. 2. In integument the conversion of the chilarities at C-3 and/or C-3′ and/or C-6 and/or C-6′ position of β- and ε-end groups in carotenoid occurred. 3. 3. In liver, β-carotene and canthaxanthin were biotransformed by reduction into vitamin A 1 alcohol. On the other hand, dihydroxy carotenoids such as astaxanthin, zeaxanthin, lutcin and tunaxanthin were directly bioconverted into vitamin A 2 alcohol.