单环刺螠体壁多糖的组成分析及基于MCM-41的吸附富集研究

本文通过胃蛋白酶酶解法提取了单环刺螠体壁多糖，进行了组成分析，并从吸附动力学、吸附热力学的角度，研究了介孔材料MCM-41对多糖的吸附。组成分析结果显示，多糖中总糖含量为（78.82%±1.40%），蛋白含量为（10.5%±1.07%），硫酸根含量为（0.52%±0.06%）；单糖组成分析结果显示，多糖主要由葡萄糖、甘露糖、半乳糖和木糖等单糖组成。红外光谱分析结果显示，多糖中含有O-H、C-O-C、C=O、S=O等特征基团，说明单环刺螠体壁多糖中含有糖醛酸组分，且存在硫酸基的取代。利用平均孔径为3.85 nm、孔容1.25 cm3/g的介孔材料MCM-41对单环刺螠体壁多糖进行富集，吸附量达到350 mg/g，吸附动力学符合准二级吸附动力学（pseudo second order adsorption kinetics，PSO）模型，吸附过程由外部扩散和颗粒内扩散控制。Langmuir和Freundlich模型均能够较好拟合吸附热力学，说明MCM-41的吸附过程主要为单分子层并伴随着多分子层的吸附。研究了不同洗脱剂的洗脱效果，发现10% SDS具有相对较强的洗脱能力。单环刺螠体壁多糖在介孔材料上的吸附研究有望为食品产业中含糖物质的富集分离提供指导。

Composition Analysis of Urechis unicinctus Body Wall Polysaccharide and Its Enrichment and Adsorption Based on MCM-41

In this paper, the polysaccharides from the body wall of Urechis unicinctus was extracted by pepsin, and the composition of the extracted polysaccharides were analyzed. The adsorption of polysaccharides on MCM-41 was studied by the adsorption kinetics, adsorption thermodynamics. The results of composition analysis showed that the content of the total sugar was (78.82%±1.4%), the content of total protein was (10.5%±1.07%), and the content of sulfate radical was (0.52%±0.06%). The monosaccharide mainly contained glucose, mannose, galactose and xylose. The results of infrared spectrum analysis showed that the polysaccharide contained characteristic groups such as O-H, C-O-C, C=O, S=O, which indicated that there were uronic acid in the polysaccharide, and there was substitution of sulfate group. The mesoporous material MCM-41, with the average pore diameter 3.85 nm and the pore volume 1.25 cm3/g, was used to enrich the polysaccharide. It was found that the adsorption kinetics of the polysaccharide on MCM-41 conformed to the pseudo second order adsorption kinetics (PSO) model, in which the external diffusion and intra particle diffusion controlled the adsorption process. The adsorption thermodynamics of the polysaccharide on MCM-41 was consistent with both the Langmuir model and Freundlich model, indicating that the adsorption process of MCM-41 was mainly monolayer and accompanied by the adsorption of multi-layer. It was found that 10% SDS had stronger elution ability, which was caused by the destruction of hydrogen bond interaction between polysaccharide and water. The study on the adsorption mechanism of polysaccharides from the Urechis unicinctus on mesoporous material MCM-41 is expected to provide theoretical guidance for the enrichment and separation of polysaccharides, oligosaccharides, glycoproteins and glycopeptides in food industry.