| Lotus-Seed (Nelumbo nucifera Gaertn), is a special economical resource in China, which has rich nutrition and special health value. Extraction technology, purified technology, Level structure, the anti-oxidantive effect and the multiplier effect of Bifidobacterium of lotus-seed polysaccharide were studied. Therefore, basic data for development of natural lotus-seed polysaccharide were offered.(1) The best extraction technology of soluble polysaccharide in Jianning lotus-seed was studied. On the basis of single-factor experiments, the optimum extraction technology was determined through orthogonal experiments: the solidliquid ratio 1:15, extracting time 3hr, extracting temperature 100℃, the extraction rate reached to 0．82%. In addition, ultrasonic and microwave on the extraction rate of lotus-seed polysaccharides were studied, the result showed ultrasonic could improve the extraction rate of polysaccharide.(2) The crude polysaccharide of lotus-seed was extracted in water, removed proteins by Sevag's methods, and was isolated and purified by DEAE-SephadexA-25．White powder State objects was obtained after freeze-drying, and the pure lotus-seed polysaccharide was identified by sephrose CL-4B gelatin chromatographic analysis and polyacrylamide gel electrophoresis analysis. The result showed that pure polysaccharide is soluble in water, insoluble in alcohol, ether, acetone and other organic solvents and has thermal stability. The polysaccharide liquid is pH 7．0 and the polysaccharide would degradate under acid alkali condition, the lotus-seed polysaccharide is a bioactive glycoprotein which contains protein 39．29% and total sugar 37．78% respectively, the percentage of SO42- is 3．61%.(3) According to the analysis of IR fingerprint characteristics absorption, the result showed that the lotus-seed polysaccharide is an acidic polysaccharide containing a carboxyl. In addition, the results of 833．14cm-1 department absorption peak and 1H-NMR. showed that the configuration of polysaccharide isα-glycosidic, HPLC analysis showed that glyconeutral sugars consist of L-rhamnose, D-arabinose, D-mannose and D-glucose. Lotus-seed polysaccharide has a molecular weight of 4484, [α]D20 =+97．4o (0．095, H2O) )and [η]=0．381． (4) The effect on scavenging·OH and·O2- of lotus-seed polysaccharide were studied by Fcnton system and Pyorgallol Autoxidation Method respectively, which was compared with the effect of tea polyphenols. The result showed that the lotus-seed polysaccharide could effectively scavenge ?OH and ?O2ˉin the experimental range, and the polysaccharide had stronger scavenging ability on·OH and lower ability on·O2ˉcompared with tea polyphenols. Moreover, the crude polysaccharide had stronger scavenging ability than the purified polysaccharide.(5) The effect on promoting the proliferation of Bifidobacterium of lotus-seed polysaccharide was studied. The result showed that lotus-seed polysaccharide could obviously promote the multiplication of B.adolescentis, The amount of living bifidobacterium appears increase as the density of the polysaccharide increases. The growing rate of mycelium(R) was increased by 100% and the generation time (G) was reduced by 35% in logarithmic phase. Furthermore, the polysaccharide had stronger multiplication ability on the B.adolescentis compared with isomalto holoside. The result indicated that lotus-seeds polysaccharide is an effective bifidus factor proliferation, which can be further developed as a growth factor of Bifidobacterium.
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