Composition and antioxidant activity of apple polyphenols in apple tissue zones

Apple polyphenols were separated in apple different tissue zones by column chromatography for apple products deveoplement. The antioxidant activities were studied by DPPH,FRAP and β- carrotene linolenic acid system. The results showed that apple polyphenols were separated into four groups: monomeric catechins,procyanidins,hydroxycinnamci acids,dihydrochalcones by Sephadex LH- 20 and p H shift technique. The most abundant compounds of apple tissue zones were procyanidins,accounting for 93.7%,79.1% and 72.3% of the total polyphenols in peel,flesh and core,respectively. Hydrocycinnamci acids accounted for 16.7% and 15.7% of the total polyphenols in flesh and core,Hidydrochalcones concertrations were the highest in core zones accounting for9.4% of total polyphenols. The top contributors to the antioxidant activity were found to be procyanidins and hydroxycinnamci acids and dihydrochalcones was the second contribution to the flesh and core,respectively.