Effects of Enzymatic Treatments of Marigold Flowers on Lutein Isomeric Profiles

Reversed-phase C 30 HPLC was applied to study the identity of lutein isomers and to monitor the effects of solids content and elimination of water-soluble substances on the isomeric carotenoid profiles of marigold ( Tagetes erecta ) samples treated with enzymes. The tentative identity of four lutein isomers present in saponified marigold extracts was confirmed. Enzymatic treatment on a 5% solids slurry produced the marigold meal with the highest all - trans -lutein content [25.1 g/kg dry weight (dw)]. We did not observe variations in the distribution in percentage of lutein isomers due to enzymatic treatment; the elimination of water solubles had a significant but small effect on such variations. The solids content was the principal factor that affected the carotenoid profiles. An analysis of the distribution showed that 15% solids gave the highest all - trans -lutein percentage in treated meals. Interestingly, with 20% solids both the degradation of lutein and the percentage of all - trans -zeaxanthin were the highest.