Carotenoids: Linearly conjugated polyene tetraterpenes are represented by carotenoids which are widely distributed
in plants and animals. The carotenoids are brightly coloured pigments in which the highly conjugated -electron
system confers different colours like yellow, orange and red to the molecule. The name carotene is derived from the
orange pigment found in carrots separated by Wackenroder (1831)[24]. There are two types of carotenoids present
in nature, carotene (e.g. β-carotene (Fig. 15) from Daucus carota) and xanthophylls (e.g. lutein (Fig. 16) from Tagetes erecta)[25].