Study on optimization of extraction process for curcuminoids by response surface method and its antioxidant activity

Response surface methodology was used to optimize the extraction process for curcuminoids. The antioxidant activity of curcuminoids was evaluated using superoxide anion(O2-·),hydroxyl(·OH),DPPH and ABTS+radical scavenging. The results indicated that the optimal extraction conditions were ethanol concentration(V/V) 85%,ultrasonic time 50 min,and material-to-liquid ratio 20∶1(m L/g). Under these extraction conditions,maximum yield of curcuminoids of 1.538% was obtained. The antioxidant experiment in vitro demonstated that the antioxidant activity of three curcumin standards were strong and different. Meanwhile the curcuminoids extract also have a better ability to scavenge superoxide anion(O2-·),hydroxyl(·OH),DPPH and ABTS+radical.