Analysis of (all-E)-lutein and its (Z)-isomers during illumination in a model system

- A C30-HPLC method was developed to rapidly separate lutein and its (Z)-isomers.
- (All-E)-lutein and twelve (Z)-isomers of lutein, in addition a small amount of (all-E)-zeaxanthin and (9Z, 9′Z)-zeaxanthin were identified.
- Five di-(Z)-luteins were identified for the first time.
- Isomerization and degradation of lutein proceeded simultaneously.
- Food matrix had a protective effect on lutein stability.