The HPLC-analysis was performed on an Agilent LC series 1200
HPLC system (Agilent Technologies, Urdorf, Switzerland) equipped
with a quaternary gradient pump, a membrane degasser, a rheodyne
injection valve with a 20 mL loop and a diode array detector.
Separations were conducted on a Nucleosil 100 C18 column
(250 mm 4.6 mm, 5 mm). The mobile phase consisted of 1%
aqueous acetic acid (eluent A) and methanol (eluent B), and was
based in the method described by Irakli et al. (2012). The linear
gradient started with 90% A, reaching 80% A at 10 min, 75% A at
20 min, 65% A at 30 min and finally 35% A at 40 min. Detection was
carried out at 320 nm. Phenolic acids in the samples were identified
by comparing their relative retention times and the respective UV
spectra with those of authentic compounds.