Phenolic compounds and antioxidant activity of Kuerlexiangli pear fruit during the growth period

Abstract:【Objective】To investigate the dynamic changes of phenolic content and antioxidant activity of different parts of the fruits of Kuerlexiangli pear during the development.【Methods】In this paper,the content of total phenols, total flavonoids, phenolic substances and their ability to scavenge ABTS+free radicals, DPPH free radical scavenging ability and iron reducing ability (FRAP) were measured in different tissue parts during the growth and development of the Kuerlexiangli pear fruits, and the corre-lations between phenolic substances and antioxidant capacity were analyzed.【Results】The total flavo-noids, total phenols, DPPH radical scavenging capacity, FRAP iron-reducing capacity and ABTS+ radi-cal scavenging capacity in the peel, flesh and extra-kernel flesh of the Kuerlexiangli pear showed an in-creasing and then decreasing trend during the growth and development of the fruits. The arbutin, chloro-genic acid, catechin, epicatechin, isorhamnose-3-O-rutinoside and isorhamnose-3-O-glucoside were de-tected in the flesh and extra-kernel flesh, the content of the arbutin was highest in the peel. The total fla-vonoids, total phenols and FRAP iron reduction capacity showed a decreasing trend in the heart of the Kuerlexiangli pear, while DPPH radical scavenging capacity and ABTS+ radical scavenging capacity showed an increasing and then decreasing trend, and the content of chlorogenic acid was highest. The antioxidant activity of phenolic substances in the fruits of the Kuerlexiangli pear was extremely high,and it was significantly positively correlated with FRAP iron reduction capacity (p < 0.01).【Conclusion】The fruits of the Kuerlexiangli pear were rich in phenolic substances, which showed a gradual de-crease with the development of the fruits. The peel and kernel had a higher content of phenolic substances and a stronger antioxidant capacity.