Then, 40 mL of acetone/water
(70:30, v/v) was added to the residue at room temperature. The
samples were extracted for 60 min and centrifuged. To determine
the antioxidant activity as well as total flavonoid, total monomeric
anthocyanin and phenolic contents, the methanol and acetone extracts
were combined and brought to a final volume of 100 mL
with distilled water.