Method for purifying lutein esters

Abstract

The invention discloses a method for purifying lutein esters and in particular relates to a method for extracting high-purity lutein esters from marigold ointment. The method is characterized by dissolving the marigold ointment into ethyl acetate at 25-80 DEG C and stirring the mixture for 1-6h; adding absolute ethyl alcohol to the liquid obtained through heat filtration and stirring the mixture at 20-70 DEG C for 0.5-5.0h to form uniform solution and then filtering the solution after cooling the solution at minus 5-30 DEG C for 5-20h; and then washing filter cakes with lower alcohol and drying the solid under vacuum to remove the solvent residues, thus obtaining the required high-purity lutein esters. The content of the lutein esters is 70-80%. The method is high in product yield, simple and convenient to operate and easy to realize large-scale industrial production.

Description

Technical field [0001] The present invention relates to a method for purifying lutein esters. More specifically, the present invention relates to a method for extracting high-purity lutein esters from marigold ointment. Background technique [0002] So far, there have been many reports on the extraction of lutein esters from marigold oleoresin. For example, US 4,048,203 uses hot alkanol containing no more than 4 carbon atoms to dissolve marigold oleoresin. The lutein ester is precipitated by cooling the solution, filtered to remove the alkanol and then vacuum dried, but the lutein obtained by this method The ester content is only 51%, which does not meet the high content requirement. In US6,191,293, the marigold flower is extracted with a hydrocarbon solvent and then with alcohol precipitation to obtain an extract, but the purity of the lutein ester obtained by this method varies greatly due to the quality of the raw materials, and it is difficult to control in industrial produc...

AI Technical Summary

Problems solved by technology

For example, US4,048,203 dissolves marigold oleoresin with hot alkanol containing no more than 4 carbon atoms, precipitates lutein esters by cooling the solution, filters and removes the alkanol and then vacuum-dries, but the lutein obtained by this method The ester content is only 51%, which does not meet the high content requirement

In US6,191,293, marigold flowers are leached with hydrocarbon solvents, and then alcoholic precipitation is used to obtain extracts, but the purity of lutein esters obtained by this method varies greatly due to the difference in raw material quality, and it is difficult to control in industrial production

In CN1,120,565A, the marigold treated with petroleum ether is extracted to obtain partially saponified oleoresin, the purity of which is only about 12.0%, and the yield is low

[0003] CN1432567A discloses first extracting lutein oleoresin with acetone, and then using butanol or isopropanol and other concentrated mother liquors of crystallized acetone, thereby obtaining a higher lutein fatty acid ester concentrate, but this method yields On the other hand, due to the use of butanol with a higher boiling point, it is difficult for the solvent residue in the product to meet the requirements of food applications. Such products will bring safety problems when used in food ingredients, and the product The ratio of cis-trans isomers of lutein fatty acid esters is greatly affected by raw materials. If the content of cis-lutein in raw materials is high, the biological activity of the product will be affected

[0004] On the whole, the prior art all has the following deficiencies: the product yield is not high; the organic solvent used in the method has a high boiling point, which is difficult to completely remove during subsequent treatment; there is a relatively high solvent residue, which is difficult to realize industrial production

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