Patent ID: 8871984

Claim:
A method for preparing xanthophyll crystals containing a high content of zeaxanthin from plant oleoresin comprising the following steps: a) mix a xanthophyll diester-containing plant oleoresin and food grade alcohol solvents through stirring to form a uniform mixed liquor, add an alkali solution to soap-dissolve the mixed liquor for 3-5 hours at a temperature range between 40° C. and 85° C.; b) add organic solvent and emulsifier to the mixed liquor obtained from step a) and stir the mixture of the mixed liquor, organic solvent and emulsifier to form a well distributed mixed liquor; c) add drop-wise an alkali solution into the mixed liquor obtained from step b) to result in the epimerization of partially gained xanthophyll crystals to transform them to zeaxanthin; d) add deionized water and alcohol solvents to dilute the reaction solution obtained from step c) to lower the concentration of the solute in the solution to a range of 10-50%, heat the mixture to a temperature range of 60-75° C. and stir the mixture for 0.5-2.0 hours to separate out carotenoid granular crystals, wherein the dosage of deionized water and alcohol solvents are 2-10 times and 0.5-2 times the weight of the raw material plant oleoresin, respectively; e) subject said granular crystals to centrifugation or filtration; f) use water heated to a temperature range of 60-85° C. to rinse the crystals obtained from step e) 2-3 times; g) use absolute ethanol to wash the crystals obtained from step f) and vacuum dry or freeze dry the crystals to obtain xanthophyll crystals containing a high content of zeaxanthin with less than 5% moisture content.