干燥方式对牛蒡多糖理化性质及抗氧化活性的影响

分别研究热风干燥、真空干燥和冷冻干燥3种方式对牛蒡粗多糖理化性质和抗氧化活性的影响。结果表明:3种干燥方式所得牛蒡多糖均为灰白色固体、是无多酚类物质的非淀粉类多糖;冷冻干燥牛蒡粗多糖的多糖含量和蛋白质含量最高,分别为(90.72±1.45)%和(2.41±0.17)%;真空干燥牛蒡粗多糖的糖醛酸含量最高,为(2.66±0.09)%;热风干燥牛蒡粗多糖的相对分子量最大,为46.74×10~4 Da。同时,冷冻干燥牛蒡粗多糖的抗氧化活性高于热风和真空干燥,其DPPH自由基和羟自由基清除率以及还原力的IC_(50)分别为2.11,2.44,3.68mg/mL。综上,考虑到多糖含量最高及抗氧化能力最好,可选用冷冻干燥方式干燥牛蒡粗多糖。

Effects of drying methods on physiochemical properties and antioxidant activities of polysaccharides from roots of Arctium lappa L.

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.