Abstract:Using the roots of Arctium lappa L. as materials to extract polysaccharides from the roots of Arctium lappa L. The influences of different drying methods were studied, including hot air drying, vacuum drying and freeze drying, on the physiochemical properties and antioxidant activities of polysaccharides from roots of Arctium lappa L.. Hot air drying, vacuum drying and freeze drying methods polysaccharides from roots of Arctium lappa L. were all gray solid, non-starch polysaccharides and no polyphenols content. Freezing drying Arctium lappa polysaccharides had higher total sugar and protein. And the contents of total sugar and protein were (90.72±1.45)% and (2.41±0.17)%. Vacuum drying Arctium lappa polysaccharides had higher uronic acid. And the content of uronic acid was (2.66±0.09)%. Three different drying methods have a certain influence on molecular weight and antioxidant activities of ALP. It was clearly demonstrated that the IC50 of hot air drying Arctium lappa polysaccharides and vacuuming drying Arctium lappa polysaccharides removing DPPH, ·OH and reducing power were higher than that of freezing drying Arctium lappa polysaccharides. The IC50 of freezing drying Arctium lappa polysaccharides on DPPH, ·OH, and reducing power were 2.11, 2.44 and 3.68 mg/mL, respecitively. Freezing drying Arctium lappa polysaccharides had higher antioxidant activities than hot air drying Arctium lappa polysaccharides and vacuuming drying Arctium lappa polysaccharides.