2.6. Analysis of total flavonoids in cookies
The flavonoid content was determined according to Eberhardt,
Lee, and Liu (2000), and expressed as mg of catechin equivalent
(CE) per kg of d.m. Briefly, 75 mL of 5 g/100 g NaNO2 solution was
mixed with 100 mL of the extract and 1.4 mL of distilled water. After
6 min, 150 mL of 10 g/100 g AlCl3 solution was added to form a
flavanoidealuminum 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.