Process for preparing xanthophyll crystal

Abstract

Disclosed a process for preparing a xanthophyll crystal, comprising: dissolving the plant extract containing a xanthophyll ester in n-hexane, then filtering the mixture; adding acetone to the filtrate, filtering and collecting a filter cake; mixing the filter cake with soybean oil and ethanol uniformly; saponifying the mixed solution with alkaline aqueous solution; then adding an acidic solution thereto until the mixed solution becomes acidic, concentrating under reduced pressure to obtain a pasty substance; adding n-hexane to the pasty saponified product, standing still and then conducting a solid-liquid separation; washing the resulting solid substance with deionized water; adding a mixed solvent to the washed solid substance, dissolving it with stirring; and then adding n-hexane thereto and standing still to recrystallize. According to the application, organic solvents are used to treat the plant extract and remove non-xanthophyll ester compounds in order to improve the efficiency of the saponification reaction; the saponified solution is concentrated under acidic condition at reduced pressure, then extracted with an organic solvent for saving water; purifying a xanthophyll crystal with a mixed solvent in order to significantly increase the purity of a xanthophyll crystal and proportion of trans-xanthophyll.