Isolation and purification of cartenoids from marigold flowers

摘要

A process for isolation of carotenoids crystals having lutein and zeaxanthin in a weight ratio of about 10:1, 5:1 or 1:1. The process comprises contacting a plant source rich in lutein with hexane and extracting at a temperature of about 40° C. to 60° C. to obtain an oleoresin rich in lutein; contacting a plant source rich in zeaxanthin with hexane and extracting at a temperature of about 40° C. to 60° C. to obtain an oleoresin rich in zeaxanthin. The oleoresin rich in lutein and the oleoresin rich in zeaxanthin are mixed separately in a ratios ranging from about 80:20 (w/w) to 90:10 (w/w) or about 70:30 (w/w) to 30:70 (w/w) or about 10:90 (w/w) to 20:80 (w/w) and homogenized to obtain a mixed oleoresin. The mixed oleoresin is hydrolyzed with an alcoholic alkali at a temperature of about 70° C. to 80° C. to obtain a reaction mixture. The carotenoids crystals are precipitated by adding hot water to the reaction mixture to form a precipitate. Carotenoids crystals having lutein and zeaxanthin in a ratio of about 10:1 or 5:1 or 1:1 respectively are obtained by filtering, washing and drying the precipitate.