Abstract: To investigate the difference of bioactive compounds and antioxidant activity in flowers and stems of pitaya,the bioactive compounds and antioxidant activity in flowers and stems of pitaya with red flesh,both self pollination and artificial pollination,were determined.The results showed that the polysaccharide content in petal,the ascorbic acid and total polyphenols content in stem of Pitaya were significantly higher than those in other parts and artificial pollination (P＜0.05).The titratable acid in stems of self pollination was significantly higher than that of flowers (P＜0.05).The titratable acid,polysaccharide,soluble protein and ABTS free radical scavenging capacity in calyx of artificial pollination were significantly higher than that in other parts (P＜0.05).The ascorbic acid,total flavonoids,total phenolics,total reducing power,of FRAP and DPPH free radical scavenging capacity in pistil of artificial pollination were significantly higher than those of other parts (P＜0.05).Correlation analysis showed that total flavonoids content was significantly positively correlated with total reducing power,FRAP and DPPH free radical scavenging capacity.All parts of pitaya with red flesh,both self pollination and artificial pollination,have high bioactive compounds and antioxidant activity.However,there is a significant difference between pollination methods and sites,and it is suggested to be targeted for rational development and utilization.

Key words: pitaya, flowers, stems, bioactive compounds, antioxidant activity
pitaya, flowers, stems, bioactive compounds, antioxidant activity