Composition and antimalarial activity of extracts of Curcuma longa L. obtained by a combination of extraction processes using supercritical CO2, ethanol and water as solvents

Rhizome of Curcuma longa L. is rich in curcumin which is also an important natural pigment and has important biological activity. In order to obtain curcumin concentrated extracts, one-step and two-step processes were employed. The one step process involves supercritical carbon dioxide (scCO(2)) at 60 degrees C and 400 bar, ethanol at 25 degrees C and water at 60 degrees C, both at atmospheric pressure. Ethanol and/or water were used as solvents. In the two-step process, sequential extraction, using scCO(2), was performed followed by ethanol or water extraction. All the extracts obtained were analyzed and results were reported for global extraction yield, the total phenolic content, total flavonoids, curcumin, antimalarial activity and antioxidant activity. The two-step process showed the highest global yield (23.4%) when water is used as solvent in the second step. However, high concentrations of curcumin and high antioxidant activity were obtained when ethanol is used as solvent The supercritical extract presents low concentration of curcumin and high antimalarial activity; which shows that extracts of different compositions and functionality can be obtained from a sequential extraction. (C) 2016 Elsevier B.V. All rights reserved.