Optimization of microwave, ultra-sonic and supercritical carbon dioxide assisted
extraction techniques for curcumin from Curcuma longa
Ultra-sonic assisted extraction (UAE)
The UAE was performed at the fixed power of 150 W using identical experimental conditions as described for MAE. Under the first
condition, dry powder (20 g) was placed in a 500 ml glass beaker
and exposed to ultrasonic waves for pre-defined time periods (1,
3, 5 or 7 min). The irradiated powder was suspended in ethanol
or acetone (mass:solvent ratio 1:3 w/v) and sonicated for 5 min
at 21 ± 2 ◦C. The samples were collected, filtered and analyzed for
curcumin content by HPLC.
In the second experimental condition, the dry powder of C. longa
(20 g) was soaked in water or ethanol (mass:solvent ratio 1:2 w/v)
for a period of 24 h at 20 ◦C. Before irradiation, the excess solvent
was removed and the wet powder was exposed to ultrasonic waves,
suspended in solvents and after extraction, samples were analyzed
as described in the first experimental condition.