A Process For Separation, Purification And Isomerization Of Natural Carotenoids, Lutein

The thesis mainly relates to a process to obtain xanthophylls concentrates of high purity from plant extracts. After drying under high vaccum, the crystalline is analyzed to be lutein with purity of more than 80 percent with IR, UV,NMR and HPLC.The thesis also relates to a process leading to the isomerization of Lutein to zeaxanthin and/or zeaxanthin-like epimers. The marigold extract is admixed with glycols and enough alkali. At the inert atmosphere, the mixture is heated to the temperature of about 100℃ for a period of time sufficient enough to complete the isomerization reaction. And the final substrate has a zeaxanthin content of about 40%, comparing to the initial content of 4.5%.A method to preparing .beta.-carotene derivatives such as canthaxanthin and astaxanthin is described. The method employs an in situ system to generate hypobromous acid as the oxidizing agent using a salt of sulfite, hydrogen sulfite orbisulfite in combination with a bromate salt. Astaxanthin and canthaxanthin are obtained in good yield with a significantly reduced reaction time.