利用超滤技术将甜菜果胶分为相对分子质量不同的4个级分，并采用高效液相色谱（HPLC）、傅里叶变化红外光谱（FT-IR）和气相色谱（GC）等技术研究了不同级分果胶分子的结构组成及其乳化特性。结果表明：甜菜果胶中截留相对分子量（MWCO）大于100,000的含量最大，达到64.86%；果胶相对分子量与其性质直接相关，随着相对分子量的增大，果胶中半乳糖醛酸、阿魏酸和酯化度均增大，单糖种类增多，而单糖的含量却减少，其分布亦有差异；相对分子量不同的果胶乳化性有很大不同，其中分子量为4.64×104Da组分的果胶乳化活性和乳化稳定最好。

Pectin extracted from sugar beet was fractionated into four fractions by filtration. The structure and emulsifying properties of pectin from the fractios were characterized by HPLC, FT-IR and GC. The results showed that the content of pectin was the highest (64.86%) when the MWCO size membrane was above 100000. Molecular weight of beet pectin was related to its physicochemical properties. And the galacturonic acid content, the ferulic acid content and degree of esterification increased with the increase of the molecular weight. The pectin emulsifying properties depended on the molecular weight. The pectin with the molecular weight of 4.64×104 Da showed the highest emulsifying activity and stability.

广东省科技计划项目（2009B040600001）；广东省国际科技合作项目（2012B050500003）； 新疆生产建设兵团重大科技专项计划—科技援疆专项（2011AB026）