Abstract: Different solvents were added in freeze-dried apple for thinning out the fruit powder, and metal salt were used to deposit apple polyphenol to change the content of polyphenol in high content leach liquor. DPPH·(1,1-Diphenyl-2- picrylhydrazyl)and ABTS·+(2,2-azino-bis-[3-ethyltiazoline-6-sulfonate) were used also to investigate the antioxidant ability of apple polyphenol. The results showed that the magnesium salt can decrease more total polyphenol,but aluminium salt is better for the deposition of flavanol. Scavenging rate of DPPH· is related to the contents of total polyohenol, however the contents of total flavanol(include catechin and polyprocyanidin)affect obviously the scavenging rate of ABTS·+. When the total polyohenol content is low, the aluminium and magnesium salts can promote free radical scavenging.

Key words: apple polyphenol, aluminium and magnesium salt, antioxidant