Determination of phenolic acids and flavonoids of apple and pear by high-performance liquid chromatography

A new HPLC stationary phase has been applied to the analysis of phenolic ac ids and flavonoids with diode array and mass spectrometric detection. The s eparation of 26 standard compounds was achieved within 1 h. The stationary phase displayed excellent resolution especially of flavonol glycosides. The analytical system has been used for the determination of phenolic compound s in apple pomace and apple juice, and in extracts of pear fruits of differ ent cultivars. Apple pomace was found to be a promising source of phenolics . However, yields are affected by the drying conditions applied. Furthermor e, the applicability of the analytical system for the authenticity control of apple and pear juice was demonstrated by determination of characteristic quercetin and isorhamnetin glycosides, and dihydrochalcones, respectively. Since isorhamnetin-3-glucoside was present in all pear cultivars investiga ted, the usefulness of arbutin as a specific marker of pear products appear s to be doubtful. (C) 2001 Elsevier Science B.V. All rights reserved.