The residue obtained
was extracted with 4 M sodium hydroxide and used for bound
polyphenol estimation and analyzed by Folin Ciocalteau's reagent
at 725 nm using gallic acid as standard (Irakli et al., 2012). The
results were expressed as milligrams of gallic acid equivalents per
100 g sample on a dry weight basis (mg GAE/100 g dw).