Abstract: Three polysaccharides (CAP-H,CAP-M and CAP-U) were extracted from Camptotheca acuminate fruit by hot water extraction,microwave-assisted extraction and ultrasonic-assisted extraction methods.Their physiochemical properties were analyzed by Fourier transform infrared spectroscopy (FTIR) analyses and differential scanning colorimeter (DSC).In additon,their antioxidant activities were evaluated by scavenging capability of DPPH free radical,hydroxyl free radical,total reducing power test and iron ion chelating ability in vitro.The results showed that the polysaccharide yield of microwave-assisted extraction was significantly higher than the other two methods.But there was no significant difference of physiochemical properties between the three polysaccharides.The hydroxyl free radicals and DPPH radical scavenging abilities of CAP-H were higher than CAP-M and CAP-U,and the IC₅₀ value were 0.775 mg/mL and 0.648 mg/mL,respectively.And CAP-H also showed significantly higher reducing power than CAP-M and CAP-U.But CAP-M showed the best iron ion chelating ability with IC₅₀value 1.745 mg/mL.

Key words: Camptotheca acuminata fruit, polysaccharides, physiochemical properties, antioxidant ability