2.4.2. Determination of total phenolic compounds The quantification of total phenolic compounds with the Foline Ciocalteau colorimetric reaction employed the method of Spanos and Wrolstad (1990).To50 mL of the sample (1 mg/mL dissolved in distilled water), 2.5mL of the FolineCiocalteu reagent (diluted 1/ 10) and 2 mL of Na2CO3 (75% p/v) were added and the mixture incubated at 45 C for 15min.