The volume was made up to 5 or 50 ml, respectively,
with solvents to obtain a final composition near to the
mobile phase (see below).
These extracts were injected in the
HPLC system.
Fruit extracts (2 ml) were saponified with 5%
potassium hydroxide for 1 h at room temperature, under nitrogen
in the dark, in a pyrogallol antioxidant medium.
After
extraction with petroleum ether and washing with water, the
solvent was evaporated and the residue dissolved in mobile
phase for analysis.