Pomace and pear fruits were extracted by stirring with aqueous acetone (70%, v/v) for 1 h at ambient temperature. After filtration, acetone was removed in vacuo (280 mbar, 308C). For the determination of catechins and procyanidins, the aqueous solution was adjusted to pH 7.0 and extracted three times with ethyl acetate (50 ml each). The combined extracts were evaporated to dryness in vacuo. The residue was dissolved in methanol (10 ml), membrane filtered (0.2 mm) and used for HPLC. For the isolation of all other polyphenols, the aqueous phase was adjusted to pH 1.5 and extracted as described above.