100 ll 0.5 M sodium hydroxide to each well and mixed. Absorbance
was measured at 750 nm using automated microplate
reader (Sunrise™-Tecan, Victory, Australia) after standing for
15 min at 25 C. Gallic acid (Sigma–Aldrich, St. Louis, MO, USA)
was used as the standard with concentrations ranging from 0.00
to 80.00 ppm. Data were expressed as in milligram gallic acid
(GAE) equivalents per 100 g of fresh weight (mg GAE/100 g).