The E161 group are Xanthophylls, (from the Greek, Xanthos -
yellow). They are yellow pigments, although E161g
is more orange, and related to carotene. Extracted using the
solvent hexane they normally contain other source plant material.
Cryptoaxanthin is also found in, amongst other things, egg
yolk and orange peel.
It is not presently commercially available but is obviously
eaten as part of a normal diet.