Improved high-performance liquid chromatography-diode array detection method for the determination of phenolic compounds in leaves and peels from different apple varieties

Hydroxycinnamic acids derivatives, monomeric and oligomeric flavan-3-ols, flavonols, and dihydrocalcones are four of the major polyphenolic groups found in apples leaves and peels. A simple extraction with minimal pre-treatment and a high-performance liquid chromatography-diode array detection determination are optimized and validated, in order to identify and quantitate the polyphenolic profile of leaves and peels of four apples varieties (Gala, Topaz, Golden Delicious, and Florina). The improved chromatographic method has led to better separation of some known polyphenols in a single course, and diode-array detection has been used for the previsional identification of some polyphenolic compounds not available as standards. Because the mobile phase and the chromatographic column are compatible with a mass spectrometer, this method could investigate the unknown flavanols, flavonols, hydrocinnamic acid derivatives, and chalcone-related compounds found in apple leaves and peel extracts analyzed.