Developmental changes in the phenol concentrations of 'Golden delicious' apple fruits and leaves

The phenolic content of apple fruit skin and leaves was determined at the developmental stage of each organ. Phenolic levels decreased on a dry weight basis during the seasonal development of fruits and leaves with respect to their ontogenesis but the single compounds did not behave uniformly. A shift in flavanol pools from monomeric to oligomeric structures during fruit growth indicated the biosynthetic tendency towards the formation of procyanidins at the end of the growing period. Among the procyanidins identified epicatechin-(4β,6)-epicatechin-(4β,6)-epicatechin has not been reported previously from apple.