Phenolic compounds in some apple (Malus domestica Borkh) cultivars of organic and integrated production

Eleven organically grown apple cultivars and 11 apple cultivars of integrated production from Austria and Slovenia were analyzed by HPLC for the content of phenolic compounds in peel and pulp. We identified chlorogenic acid, p-cournaric acid, procyanidin B3, protocatechuic acid, (-)-epicatechin, phloridzin, rutin and quercetin-3-rhamnoside in apple peel. In apple pulp, (+)-catechin was also identified in all the cultivars. Some other phenols (procyanidin B3, rutin and quercetin-3-rhamnoside) could not be identified or were not properly separated. With regard to the phenolic content in the apple peel, there were no differences between organically grown apple cultivars and apple cultivars of integrated production. Organically grown apples, however, exhibited a higher content of phenolic substances in the apple pulp compared with the apple cultivars of integrated production. This may be due either to the different genotype source or to the growing technology. Higher concentrations of phenolic compounds in organically grown cultivars could be a result of plant response to stress. The apple peel contained higher concentrations of identified phenols than the pulp. The apple peel represents up to 10% of the whole fruit; therefore the phenolsic compounds in the pulp are of greater importance to the consumer than the phenolic compounds in the peel. (c) 2005 Society of Chemical Industry.