Cur@starwas added to ethanol at the concentration of 0.2 mg/mL
and treated in a bath type sonicator for 30 min to extract the curcumin.
After that, the ethanol solution was centrifuged at 3000 rpm
for 10min and the residue in the centrifuge tubewas extracted again
under the same conditions. Ethanol solution that contained curcumin
was removed from the supernatant and combined. Curcumin
concentration was determined on a UVevis spectrophotometer at
419 nm according to the following calibration curve: