文献类型： 外文期刊

作者： Zhang, LN ¹ ; Xu, XJ ² ; Zhang, M ² ; Chen, JH ² ; Meng, DY ² ; Ren, LW ² ; Iijima, H ² ;

作者机构： 1.Wuhan Univ, Dept Chem, Wuhan 430072, Peoples R China

2.Wuhan Univ, Dept Chem, Wuhan 430072, Peoples R China; Hubei Acad Agr Sci, Agr Testing Ctr, Wuhan 430064, Peoples R China; Asahi Chem Ind Co Ltd, Chem Technol Dept 4, Miyazaki 8820847, Japan

关键词： Erwinia gum;molecular weight;aggregation;GPC;light scattering

期刊名称：JOURNAL OF APPLIED POLYMER SCIENCE （ 影响因子：3.125； 五年影响因子：2.754 ）

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收录情况： SCI

摘要： Erwinia (E) gum, a stabilizer and thickening agent of food, is composed of glucoes, fucose, galactose, and glucuronic acid (1 : 0.1 : 0.05 : 0.3 by molar ratio). The apparent weight-average molecular weight M_w and intrinsic viscosity [#eta#] in 0.2 M NaCl aqueous solution were measured to be 7.83×10~5 and 268 mL g~(-1), respectively, but light scattering and viscometry. The aggregation behavior of E gum in aqueous solution was investigated by gel permeation chromatography (GPC) and dynamic light scattering. The results showed that 7.5% E gum exists as an aggregate, whose diameter is 12 times greater than single-stranded chain, in aqueous solution at 25degC, and the aggregates' content decreased with increasing temperature of decreasing polymer concentration. The aggregates at higher temperature were more readily broken than in exceeding dilute solution. GPC analysis proved that a significant shoulder, corresponding to a fraction of higher molecular weight due to chain aggregation, appeared in the chromatogram of E gum in 0.05 M KH_2PO_4/5.7×10~(-3) M NaOH aqueous solution (pH 6.0 at 35degC, and decreased with increasing temperature, finally disappeared at 90degC. The disaggregation process of E gum in aqueous solution can be described as follows: with increasing temperature, large aggregates first were changed into the middle, then disrupted step by into single-stranded chains.