Polyphenol composition and total antioxidant capacity of selected apple genotypes for processing

The phenolic composition, concentration and total antioxidant capacity (TAC) were determined in the flesh and peel of eight advanced cider apple breeding lines and cultivars to be used for cider production in Canada. The total phenolic content (TPC) assayed by the Folin–Ciocalteu method, the individual phenolics determined by HPLC/DAD and TAC measured using ferric reducing antioxidant power (FRAP) differed significantly among the advanced apple lines and cultivars studied. Higher concentrations of the measured parameters were found in the peel of all tested lines compared to the flesh. "McIntosh Summerland" and "Spartan" had the highest concentrations of polyphenols and TAC and "SJCA16R5A15" had the lowest. There was a positive correlation between TPC and TAC in both flesh and peel (R2=0.74 and 0.51, respectively). However, a weak correlation was found between total phenolics determined by HPLC and TAC (R2=0.29 and 0.43 in flesh and peel, respectively). Results showed that procyanidins are the most predominant phenolic group in both flesh and peel, followed by hydroxycinnamic acids in the flesh and flavonols in the peel, and all are of great interest in cider making.