2.5. Polyphenolic composition by HPLC–DAD
Musts were analyzed by direct injection (Spanos & Wrolstad, 1990), after filtration through 0.45 lm filter (Durapore membrane filters. Millipore – Ireland). HCA and GRP were detected at 320 nm. Peaks were identified by comparing their retention time and UV– Vis spectra with the pure standard and they were quantified with the external standard method. An Agilent Eclipse XDB-C18, 4.6 150 mm, 5 lm was used for the separation. The column was thermostated at 40 C. All standards were dissolved in methanol, and results are expressed in mg/L of must.