MTG酶诱导大豆11S球蛋白透明冷致水凝胶的制备

水凝胶的制备逐步朝向安全无毒、高生物相容性的方向发展。本工作着重探究一种大豆球蛋白透明冷致水凝胶的制备方法。首先利用葡聚糖硫酸盐（dextran sulphate, DS）与大豆11S球蛋白（glycinin, 11S）在加热过程中形成多阴离子复合物，继而采用微生物转谷氨酰胺酶（microbial transglutaminase, MTG酶）在pH 7.0、一定离子强度条件下，通过分子间ε-（γ-谷氨酰胺基）赖氨酸共价键交联，制备了透明冷致水凝胶，并对其流变学、质构特性、持水性及微结构进行研究。结果表明：葡聚糖硫酸盐（DS）的添加赋予大豆11S球蛋白溶液较高的荷电量，在中性条件下，MTG酶具有交联此高荷电多阴离子复合物的能力，从而在较低温度下形成透明冷致水凝胶。通过控制

Preparation of microbial transglutaminase-induced soybean glycinin transparent cold-set hydrogels

A novel method of preparing transparent cold-set hydrogels by soybean glycinin (11S）was developed.Addition of dextran sulphate (DS）to soybean glycinin (11S）in the first step induced the 11S/DS solution to form soluble complexes with higher negatively charged, which had a significant effect on improving transmittance after the preheat process.Cross-linking with microbial transglutaminase (MTGase）was used in the second step, and transparent gels were formed by ε-(γ-glutamyl）lysine isopeptide bonds at pH 7.0 with low ionic strength.The result indicated that transparency markedly increased at DS/11S (mass ratio）of 0.005 or more and decreased when NaCl was involved and much better hardness was achieved by covalent bond crosslinked with MTGase.Scanning electron microscopy showed finer and more intensive networks of gels were formed by addition of DS.Water holding capacity (WHC）increased when more DS was added.The combined effects of DS concentration and ionic strength influenced the rheological properties, and determined texture properties of gels.The inhibitory effect of DS would be ascribed to the formation of firmer and transparent soybean glycinin gels with better characteristics.