After 6 min, 150 mL of 10 g/100 g AlCl3 solution was added to form a flavanoide aluminum complex.
After 7 min, 500 mL of 1 mol/L NaOH was added, and after 10 min the mixture was centrifuged at 9000g for 5 min. Absorbance of the supernatant was measured at 510 nm.
aluminum complex