3.2.1. Determination of Total Phenolic Contents (TPC)

The total phenolic content was determined using Folin–Ciocalteu reagent according to the method described by [115]. As follows: 20 μL of the sample was mixed with 100 μL of Folin–Ciocalteu reagent (10%), and 75 μL of aqueous sodium carbonate solution (7.5%, w/v), then the mixture was incubated at room temperature and in the dark for 2 h. The absorbance was measured at 765 nm using a microplate reader of type PerkinElmer (Enspire). Gallic acid was used as a standard for plotting the calibration curve. The total phenolic content was expressed as milligrams of gallic acid equivalents (GAE) per gram of dry weight.