IMPROVEMENT OF THE ISOLATION AND PURIFICATION OF LUTEIN FROM MARIGOLD FLOWER (TAGETES ERECTA L.) AND ITS ANTIOXIDANT ACTIVITY

Abstract

ABSTRACT Lutein is associated with the prevention of many chronic diseases, like age‐related macular degeneration, cancer and cardiovascular diseases. Lutein is found in many plants, but the purest and richest source is the petals of marigold flowers (Tagetes erecta L.). Commercially prepared T. erecta extract (oleoresin) was used during the experiment. Saponification reaction was carried out using alcoholic potassium hydroxide solution and tetrahydrofuran at room temperature for 4 h to saponify the xanthophyll esters. The purity and recovery of lutein after saponification were 89 and 63.05%, respectively. Different solvents were used for recrystallization to get a high purity of lutein. Among them, purity and recovery of lutein reached >98 and 72% in ethyl alcohol, which were higher than reported earlier. The scavenging efficacy of lutein against peroxide, superoxide anion, hydroxyl radical and lipid free radicals was measured by chemiluminescence. Peroxide, superoxide anions and hydroxyl and lipid free radicals were generated by hydrogen peroxide, pyrogallol, Fenton reaction system and 2,2′‐azobis (2‐amidino‐propane) dihydrochloride‐induced γ‐linolenic acid peroxidation system, respectively. Lutein exhibited strong antioxidant activity against superoxide anion, peroxide and hydroxyl and lipid free radicals. Among all tested reactive oxygen species, lipid free radicals showed the lowest effective concentration. A reaction time of 6 s was enough to scavenge superoxide and hydroxyl radicals, while it was 60 and 120 s for peroxide and lipid free radicals, respectively. PRACTICAL APPLICATIONSThis work was performed to demonstrate that high purity of lutein can be recovered using tertrahydrofuran and alcoholic potassium hydroxide at room temperature. Ethyl alcohol can be used as a recrystallizing solvent for lutein. Dissolved impurities from the lutein can be removed by washing during filtration. The scavenging activity of lutein against peroxide, superoxide anions and hydroxyl and lipid free radicals in the chemiluminescence meter enhanced the nutraceutical value of lutein.