centrifugation
were repeated. Both methanolic and acetonic extracts were
combined and centrifuged at 3500 g for 15 min. The resulting
supernatant was transferred into tubes and directly used for the
determination of antioxidant capacity and total polyphenol
content.
Residue. Residues were left in a ventilating and heating apparatus
(max temperature 25 C), until dryness. Briefly, 300 mg of the
residue were mixed with 20 mL of methanol and 2 mL of concentrated
sulfuric acid (18 M). The samples were gently stirred for
1 min and were shaken in a water bath at 85 C for 20 h.
The samples were then centrifuged (3000g for 10 min), and the
supernatant was recovered. After two washings with minimum
volumes of distilled water and recentrifuging as necessary, the final
volume was taken up to 50 mL. The tube was centrifugated at
3500g for 20 min and was transferred into tubes and directly used
for the determination of antioxidant capacity and total polyphenol
content.