Chemical composition and biological activities of peels and flesh from ten pear cultivars ( Pyrus ussuriensis )

This study aimed to determine the chemical composition (sugars, organic acids, and phenolics) and biological activities (in-vitro antioxidant, anti-inflammatory and antibacterial activities) of peel and flesh tissues from 10 Pyrus ussuriensis cultivars. Four sugars and eight organic acids were identified by HPLC. The phenolic profile determined by UPLC-MS resulted in the quantification of six groups of phenolic compounds. The total phenolic contents ranged from 453.53 to 1502.04 mg/kg FW in the peels and from 51.80 to 153.98 mg/kg FW in the flesh. Antioxidant activity, determined by DPPH and FRAP, reached 35.11 and 41.63 µmol TE/g FW, respectively. The anti-inflammatory activity of the fruit extract was significant and comparable with the standard anti-inflammatory drug, diclofenac sodium. Further antibacterial assays showed that the fruit extracts displayed intriguing biological activity. Among all cultivars, ‘Pingdingxiang’ and ‘Jinxiangshui’ presented the highest concentrations of phenolic compounds and the most significant antioxidant properties, whereas the flesh of ‘Honghuagai’ showed optimal anti-inflammatory and antibacterial activities in the flesh. The results shown here may be of interest for a breeding program aimed at enhancing nutritional value and, therefore, meeting the expectations of consumers for fruit with many health benefits and a specific taste.