US Patent 7390914 Process for the preparation of lutein ester concentrate

A method for concentrating trans-xanthophyll esters from marigold oleoresin, which includes blending the oleoresin with a solvent and a co-solvent of lower alkanols and recovering a precipitate enriched with trans-xanthophyll esters at a temperature of above 22° C. The recovery of the trans-xanthophyll esters is greater when using the alkanol blend than when using only a lower alkanol from the said blend. The said process is most useful using a lower-grade, commercially available oleoresin, thereby helping small producers, who do not have access to higher-grade oleoresin made through backward integration to marigold cultivation and harvest.