| abstract |
A practical and effective process for isolating and purifying mixed carotenoids containing higher concentrations of specific compounds, such as all-trans lutein, without the use of harmful organic solvents, is disclosed. The process employs hydrolysis of carotenoid esters in a mixture of isopropanol, water, and alkali to separate the carotenoids from other impurities. The carotenoids are purified further using aqueous precipitation, followed by centrifugation and drying under vacuum. The product is a fine crystalline powder with very low residual solvents (hexane 0.22 ppm; isopropanol 0.53 ppm) suitable for human consumption, either in nutritional supplements or as a food additive. |