Metabolomics of carotenoids: The challenges and prospects A review.

Considerable progress in carotenoids research has been made
to understand the carotenoid metabolism in animals including
human. Epidemiological and clinical studies have correlated
with dietary intake of carotenoids on reduction of vitamin A
deficiency, age-related macular degeneration, cancer and cardiovascular
diseases. Recent findings demonstrate the existence
of carotenoid metabolites in vivo and their efficacy
have made greater insight on prospecting carotenoid metabolites.
Owing to their biological activity, exploration of analytical
methods for the characterization of carotenoid
metabolites is considered to be important before addressing
the stability and bioactivity. Although few studies are available
on carotenoid metabolites, their structural characterization in
biological samples require a substantial refining of analytical
protocols like isolation, purification, prerequisite of equipment
parameters and robustness in hyphenated techniques.
Recently, researchers have focused on biotransformation of carotenoids
and made an attempt to screen their metabolites by
high-throughput analytical strategies. However, till date there
is no detailed analytical techniques available to fingerprint
carotenoid metabolites, due to interference with complex biological
matrices. This review highlights the carotenoid metabolism,
possible bioconversion and available bio-analytical
techniques to characterize metabolites in vivo. Further,
advancement in sensitivity, mode of ionization and fragmentation
patterns of metabolites were also discussed. The identification
of carotenoid metabolites in system specific will have
further insight in the emerging field of nutritional
metabolomics.