Phenolic profiles and antioxidant activities of exocarp, endocarp, and hypanthium of three pear cultivars grown in China

The phenolic composition of the exocarp, hypanthium, and endocarp from three pear cultivars: Jingbai, Korla and Crystal were measured by high-performance liquid chromatography method with diode array detection (HPLC-DAD), while antioxidant activities were investigated using DPPH radical andABTS radical cation scavenging activity, and FRAP. Ferulic acid, chlorogenic acid, and caffeic acid were detected as major components. The exocarp of the Jingbai pear had a relatively high chlorogenic acid content (0.691 mg kg-1) while the hypanthium and endocarp had the high chlorogenic acid content of the three pear varieties. The exocarp of the Korla pear had the highest ferulic acid and rutin content. The exocarp, hypanthium, and endocarp of the Crystal pear had the highest content of chlorogenic acid of the three pear varieties. The Crystal pear presented the highest total phenolic and flavonoid contents and had the highest antioxidant activities in terms of FRAP. The Jingbai pear exocarp presented the highest ABTS value, 83.62 ± 0.08%. The endocarp of the Crystal pear had the highest DPPH value, 87.30 ± 0.03%. Positive correlations were detected among chlorogenic acid, TPC, TFC, and FRAP. The results reveal that the different parts of Pyrus communis L. have effective antioxidant activity for the pharmaceutical application.