Carotenoids, the most common fat-soluble plant pigments in nature, are beneficial to human health due to their strong antioxidant activities and abilities to prevent various diseases. Carotenoids have many geometrical isomers forms caused by E/Z-isomerization at arbitrary sites within the multiple conjugated double bonds. Several studies have addressed that the bioavailability as well as the antioxidant, anticancer, and antiatherosclerotic activities of carotenoids varies among the isomers. In addition, those variations differ among carotenoids: Z-isomerization resulted in “positive” or “negative” effect for carotenoids bioavailability and functionality, for example, Z-isomers of lycopene are more bioavailable than the all-E-isomer, whereas the opposite is observed for β-carotene. Thus, to efficiently promote the beneficial effects of carotenoids by ingestion, it is important to have a good understanding of the impact of E/Z-isomerization on the corresponding functional changes. The objective of this contribution is to review the effects of carotenoid Z-isomerization on bioavailability and functionality and describe their differences among carotenoids.
Part of the book: Progress in Carotenoid Research