US Patent 7297803 Process for the preparation of lutein ester concentrate

A method for concentrating trans-lutein 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-lutein esters at a temperature of above 22° C. The recovery of the trans-lutein esters is greater using the alkanol blend than when using only a lower alkanol in the said blend. The 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.