4.4. Folin–Ciocalteu Method to Measure Total Phenolic Contents

The TPC in the different melon extracts was determined by the F–C assay, as previously described, with slight modifications [44]. To determine the total phenolic content microplate in the melon extracts, standard gallic acid (50 µg mL⁻¹) was pipetted in the first 3 columns of the 96-well in increasing concentrations (10, 20, 30, 40, 50, 75, and 100 µL), then the volume in standard wells was adjusted accordingly with Nanopure water to obtain a total volume of 180 µL. In the sample wells, 20 µL aliquots of extract were pipetted. The volumes in each sample wells were also adjusted to 180 µL with Nanopure water. Then, 20 µL of Folin–Ciocalteu working solution was added to all wells and then incubated the plates in the dark briefly for 10 min followed by addition of 50 µL of sodium carbonate in all wells and further incubated for 20 min in the dark. The absorbance was monitored at 760 nm using the microplate and TPC was expressed as micrograms of ascorbic acid equivalent g⁻¹ of the sample.