Polyphenolic composition and antioxidative activity of apple flesh extracts

The polyphenolic composition and the antioxidative activity of an apple flesh extract and its fractions toward linoleic acid peroxidation in micelles of sodium dodecyl sulfate in buffer solution was studied. 1. The main phenolic compounds in fraction B extracted with ethylacetate from aqueous sample solution were chlorogenic acid, (+)-catechin, (-)-epicatechin, oligomeric procyanidins and phloridzin, and in fraction A, which remained in the aqueous phase, polymeric procyanidin was predominant. 2. Catechins (monomeric forms) and procyanidins (oligomeric and polymeric forms), especially polymeric procyanidin, were predominant polyphenolic compounds in apple flesh. 3. The relationship between polyphenolic concentration and antioxidative activity of apple flesh extract was almost same as that of standard (-)-epicatechin solution. In comparison between fraction A and B, the antioxidative activity of fraction B was slightly superior to that of fraction A. 4. The free radical scavenging activity of dimeric and trimeric procyanidins measured with a diphenyl-p-picryl hydrazyl (DPPH) method was stronger than that of monomeric catechins, the same as the result of antioxidative activity in the SDS micellar system. The antioxidative activity of the fraction including polymeric procyanidin was lesser than that of catechins or dimeric and trimeric procyanidins, whereas the DPPH radical scavenging activity of this fraction was superior to catechins or dimeric and trimeric forms.