has role independent continuant carotenol lutein Xanthophyll Lutein E 161b lutein (3R,3'R,6S)-4,5-DIDEHYDRO-5,6-DIHYDRO-BETA,BETA-CAROTENE-3,3'-DIOL (3R,3'R,6'R)-beta,epsilon-carotene-3,3'-diol Bo-Xan (3R,3'R,6'R)-beta,epsilon-carotene-3,3'-diol (6'R)-beta,epsilon-carotene plant metabolite food colouring