Abstract:To explore the distribution of polysaccharides with higher antioxidant activities in lotus root, polysaccharides in edible part, peel, and node (i.e. EP60/75/90, PP60/75/90 and NP60/75/90) were respectively isolated using a precipitation method coupled with gradually increased alcohol concentrations. While the basic components, physicochemical characteristics, and antioxidant activities were further analyzed. Polysaccharides from different parts of lotus root showed obvious differences in composition, and edible part polysaccharides (EPs) had lower purities compared with peel polysaccharides (PPs) and node polysaccharides (NPs). Based on high performance molecular-exclusion chromatography, it was found that lotus root polysaccharides were mainly composed of fractions with low molecular weight (1.30-1.63ku) and less binding protein. The antioxidant evaluations in vitro confirmed that the antioxidant activities of EPs were weaker than those of PPs and NPs, especially DPPH radical scavenging ability and FRAP total antioxidant capacity (p<0.05). The antioxidant activities of PPs could be ordered as PP60>PP75>PP90. Meanwhile, the activities of NP60 and NP90 were matched, which exhibited stronger hydroxyl radical scavenging capacities and weaker FRAP total antioxidant capacities than NP75 (p<0.05). The polysaccharides with higher antioxidant activities mainly exist in the peel and node of lotus root, which might be related to binding protein content and molecular weight.