2.3. Determination of total phenolic content (TPC) in Senjed
peel aqueous extracts
Total phenolic compounds in the extracts were determined, using
Folin–Ciocalteau reagent, by the method of Hussain et al. (2018) and
expressed as mg/g of Gallic acid equivalents (GAE) as a standard. 0.5 mL
of extracts (at a concentration of 1–10 mg/mL extracts in water) was
mixed with 2.5 mL of 10% Folin-Ciocalteu reagent and 2 mL of 7.5%
sodium carbonate solution. After the samples were kept for 30 min at
room temperature for incubation, the absorbance was measured at 760 nm
in a UV/visible spectrophotometer (Ultrospec 2000; Pharmacia Biotech
Ltd., Cambridge, UK).