Determination of total phenolic content
Total phenolic content (TPC) was determined
using Folin–Ciocalteu reagent as followed by Bakar
et al. (2009). Briefly, 300 μl of extract was mixed
with 2.25 ml of Folin–Ciocalteu reagent (previously
diluted 10-fold with distilled water) and allowed
to stand at room temperature for 5 min; 2.25 ml of
sodium carbonate (60 g/l) solution was added to
the mixture. After incubation for 90 min at room
temperature, absorbance was measured at 725 nm
using spectrophotometer. Results were expressed as
mg gallic acid equivalents in 1 g of dried sample (mg
GAE/g).