Ultrasound-assisted Extraction of Curcuminoids from Turmeric (Curcuma longa L.)

Three main curcuminoids including bisdemethoxycurcumin (Cur I), demethoxycurcumin (Cur II) and curcumin from turmeric (Curcuma longa L.) were extracted with the assistance of single or dual frequency ultrasound (CA E) and compared with the conventional solvent extraction (CSE). Effects of ultrasound frequency, ratio of solvent to material, temperature and ethanol concentration on the extraction yields of three curcumonoids were investigated The optimal extraction parameters are as follows: ethanol concentration of 65%, ratio of solvent to material of 100:1, temperature of 65 degrees C, ultrasound frequency of 28+40 kHz and extraction time of 100 min. Under these conditions, the extraction yields of three curcuminoids are 9.31, 11.39 and 21.52 mg/g, respectively The efficiency and the yields of ultrasound-assisted extraction are higher than conventional solvent extraction. The kinetic and thermodynamic parameters of two extraction methods were also compared in the study.