Process for extraction and purification of lutein, zeaxanthin and rare carotenoids from marigold flowers and plants
AssigneeUniversity of Maryland, College Park
InventorFrederick Khachik
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Abstract
A process for extracting and isolating carotenoid esters or carotenoids in high purity from plants without the use of harmful organic solvents. Zeaxanthin esters were isolatd and purified from the berries of Lycium Chinese Mill (LCM berries). The esters isolated according to the invention contain substantially no isomerized double bonds. The purified carotenoid esters or carotenoids isolated by this process are free from impurities and serve as a safe source of nutritional supplement for human consumption as well as providing a suitable and effective color additive for human foods.
Claims38
A method for the extraction of carotenoid esters, with substantially no isomerization of the double bonds, from a plant source containing carotenoid esters, comprising extracting carotenoid esters from said plant source by contacting the plant source with one or more solvents to obtain a mixture;
- removing undissolved solids to obtain a liquids portion;
- removing the one or more solvents from the mixture under conditions which result in substantially no double bond isomerization to obtain a residue;
- and isolating the carotenoid esters.
A method for saponifying carotenoid esters, with substantially no isomerization of the double bonds, comprising contacting said esters with a solution comprising tetrahydrofuran and an alcohol at an elevated pH to obtain a mixture comprising hydrolyzed carotenoid;
- neutralizing the base with a dilute acid;
- removing the tetrahydrofuran and alcohol under conditions which result in substantially no double bond isomerization to obtain a residue comprising carotenoids free from esters;
- washing the residue with an aqueous solution to give carotenoid crystals;
- and collecting the carotenoid crystals.
A method for the simultaneous extraction and hydrolysis of lutein esters or zeaxanthin esters, with substantially no isomerization of the double bonds, from at least one of marigold petals and Chinese Wolfberries, comprising extracting and saponifying said lutein esters and/or zeaxanthin esters from said petals or said berries by contacting said petals and/or said berries with a solution comprising tetrahydrofuran and an alcohol at an elevated pH to obtain a mixture comprising hydrolyzed lutein or zeaxanthin;
- removing solids from the mixture to obtain a liquids portion;
- stirring at room temperature;
- neutralizing the solution with a dilute acid;
- removing the tetrahydrofuran and alcohol from the liquids portion under conditions which result in substantially no double bond isomerization to obtain a residue comprising lutein free from esters and/or zeaxanthin free from esters;
- washing the residue with an aqueous mixture to give lutein and/or zeaxanthin crystals;
- and collecting lutein and/or zeaxanthin crystals.
A method for the extraction of zeaxanthin esters with substantially no isomerization of the double bonds from Chinese Wolfberries containing zeaxanthin esters, comprising contacting the Chinese Wolfberries with one or more solvents to obtain a mixture;
- removing undissolved solids to obtain a solution of the zeaxanthin esters;
- adding water to the solution;
- removing the one or more solvents from the solution under conditions which result in substantially no double bond isomerization;
- adding one or more solvents to the residue;
- and isolating zeaxanthin esters.
A method for saponifying zeaxanthin esters, with substantially no isomerization of the double bonds, comprising contacting said esters with a solution comprising tetrahydrofuran and methanol or ethanol at pH about 12 to obtain a mixture comprising hydrolyzed zeaxanthin;
- contacting the mixture with an acid such that the pH of the mixture is about 7.0-7.5;
- removing the tetrahydrofuran and methanol or ethanol under conditions which result in substantially no double bond isomerization, to obtain a residue comprising zeaxanthin free from esters;
- contacting the residue with a solvent to give zeaxanthin crystals;
- and collecting the zeaxanthin crystals.
Dependencies are inferred from the claim text.