Extraction of Lutein from Okra Leaves by Ethanol-Ammonium Sulfate Aqueous Two-Phase System

In this study,an aqueous two-phase system composed of ethanol and ammonium sulfate was selected to extract lutein from freeze-dried okra leaf powder. On the basis of single factor test,the response surface of ethanol mass fraction,ammonium sulfate mass fraction and crude extract mass fraction were optimized with three factors and three levels. The results showed that the optimized extraction process conditions were 6% of crude extract,14.5% of ethanol and 27.5% of ammonium sulfate. The yield was 1.99 mg/g under this condition.The kinetic study of the crude extract of lutein from ultrasonic assisted extraction showed that the extraction conforms to the second order kinetic equation. The lutein extracted by this method was compared by V_C,and the IC₅₀ value of lutein on ABTS free radical and DPPH free radical were 0.2841 and 0.7633 mg/mL,respectively,which had certain antioxidant activity.