2.6.1. Total soluble polyphenol (TSP) profile HPLC analysis
Partial identification of PPs was performed using a chromatograph (Dionex, ICS-5000, DC-5 USA) HPLC-DAD (diode array detector) system. The separation was achieved with a reverse phase column Acclaim C18 (300 × 3.0 mm i.d., 5 μm particle size, Thermo Scientific, USA). The mobile phases were: acidified water with 0.1% trifluoroacetic acid (TFA) and 85% acetonitrile with 0.085% TFA acidified in a gradient program with 1 mL/min of flow rate, and injection volume of 50 μL. Detection was carried out in a wavelength scan from 214 to 520 nm. The compounds were identified by comparison of retention time and spectrum of the major compounds present in the samples.