.3. Total phenolic content (TPC)
A serial dilution (5 - 30 mg/ml) of standard gallic acid purchased from Fluka (USA) was prepared in H_2O to generate a calibration curve (r > 0.999). The sample was mixed with water, FolinCiocalteu reagent (Carlo erba, Italy) and 2% Na_2 CO_3 (Fisher, UK) prior to incubation for 1h at ambient conditions. Absorbencies were recorded at 750 nm using a microplate reader. The TPC was calculated and expressed as g of gallic acid equivalents per 100 g of extract(gGAE/100gextract).All measurements were performed in triplicate (Tepe and Sokmen, 2007).