Abstract In this study, we extracted polysaccharide from Sporophyll of Undaria pinnatifida Suringar and performed it to reveal the effect of dehydration mode on polysaccharide free radical scavenging ability. The polysaccharide extract was dried by vacuum freeze-drying, vacuum drying and hot-air drying methods, respectively. The result elucidated that these products by three kinds of drying methods showed different clearance abilities in DPPH , OH and ABTS scavenging free radicals tests, with the following order: vacuum freeze-drying > vacuum drying > hot-air drying. They showed similar characteristic in Infrared Spectroscopy and X-ray Diffraction spectrum, but have different interaction patterns with water in Low Field Nuclear Magnetic Resonance. The scavenging ability difference may due to the amount of bound water and immobilized water in dried status. The absence of immobilized water on polysaccharide would facilitate the functional groups to reach to the free water molecule and help for the polysaccharide to form triple helix stereo-configuration in solution.

中文翻译：

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干燥多糖上的水分子附着方式影响其自由基清除能力

摘要 本研究从裙带菜的孢子叶中提取多糖并进行提取，以揭示脱水方式对多糖自由基清除能力的影响。多糖提取物分别采用真空冷冻干燥、真空干燥和热风干燥方法进行干燥。结果表明，三种干燥方式的产物在DPPH、OH和ABTS清除自由基试验中表现出不同的清除能力，顺序为：真空冷冻干燥>真空干燥>热风干燥。它们在红外光谱和 X 射线衍射光谱中表现出相似的特性，但在低场核磁共振中与水的相互作用模式不同。清除能力的差异可能是由于干燥状态下结合水和固定水的含量不同。多糖上不存在固定水将促进官能团到达游离水分子并有助于多糖在溶液中形成三螺旋立体构型。