3.4. Total Phenolic Content (TPC) Determination

TPC was assessed through a variation of the Folin-Ciocalteu method [79]. Hence, 50 µL of the phenolic extracts were mixed with 430 µL of distilled water and 20 µL of the Folin-Ciocalteu reagent. After stirring, 50 µL of a 20% w/v solution of Na₂CO₃ were mixed and left 10 min to rest. The mixture was then diluted with 450 µL of distilled water, and its absorbance was read at a wavelength of 725 nm using a ThermoScientific Genesys 10S UV-Vis spectrophotometer (Waltham, MA, USA) at room temperature. A calibration curve was prepared by dissolving gallic acid in distilled water in known concentrations ranging from 0 to 200 ppm. Phenolic concentration from analyzed samples was expressed as Gallic Acid Equivalents (GAE). Measurements were performed in triplicate.