Abstract: This invention has disclosed a method for preparation of food-grade zeaxanthin through chemical isomerizaton reaction from lutein. The technical issues to be solved in this invention are quite low product yield obtained with existing methods, need of purification treatment process, and inadaptability to industrialized production. The technical schemes of this invention are: a. Mix xanthophyll crystal or its fatty acid ester with food-grade glycol or propylene glycol, for full dissolution under 60-90° C. temperature. Add organic alkali into the mixed liquor acquired from step 1, for isomerization reaction to take place under inertial environment. c. Dilute the reaction solution gained from step b with the mixed solution of deionized water and ethanol, and separate the obtained crystal with conventional separating method. d. Vacuum dries the acquired crystal from step c, to get the zeaxanthin crystal.

Abstract: This invention has disclosed a method for preparation of food-grade zeaxanthin through chemical isomerizaton reaction from lutein. The technical issues to be solved in this invention are quite low product yield obtained with existing methods, need of purification treatment process, and inadaptability to industrialized production. The technical schemes of this invention are: a. Mix xanthophyll crystal or its fatty acid ester with food-grade glycol or propylene glycol, for full dissolution under 60-90° C. temperature. Add organic alkali into the mixed liquor acquired from step 1, for isomerization reaction to take place under inertial environment. c. Dilute the reaction solution gained from step b with the mixed solution of deionized water and ethanol, and separate the obtained crystal with conventional separating method. d. Vacuum dries the acquired crystal from step c, to get the zeaxanthin crystal.

Abstract: A process for isolation and purification of xanthophylls crystals from plant oleoresin is disclosed. The organic solvents involved in the process is no other than food grade alcohol. The process includes saponifying the plant oleoresin containing xanthophyll diesters, neutralizing the saponified reaction mixture with an acid and washing water-soluble impurities and other fat-soluble oil with warm water and alcohol, respectively. The process can improve purity and yield of products, by which the content and the recovery of xanthophylls are as high as 90% and 80% respectively. And the process is economical and easy to perform in industrial production.

Abstract: A process for isolation and purification of xanthophylls crystals from plant oleoresin is disclosed. The organic solvents involved in the process is no other than food grade alcohol. The process includes saponifying the plant oleoresin containing xanthophyll diesters, neutralizing the saponified reaction mixture with an acid and washing water-soluble impurities and other fat-soluble oil with warm water and alcohol, respectively. The process can improve purity and yield of products, by which the content and the recovery of xanthophylls are as high as 90% and 80% respectively. And the process is economical and easy to perform in industrial production.