Polyphenols were extracted from the lyophilized samples (1 g)
following the procedure of Bravo and Saura-Calixto (1998). The
Folin–Ciocalteau method was used to quantify the extractable
polyphenols by spectrophotometry at 750 nm (UV/Vis Lambda
EZ210, Perkin–Elmer, Jügesheim, Germany). Results were
expressed as equivalents of gallic acid