Systematic study on polysaccharide gels for the creation of new texture modifiers

通过对系列凝胶样品的静态和动态光散射和粘度的测量，定量地评价了凝胶分子在有序和无序状态下的链刚性，并表征了凝胶结构的基本原理。采用6个钠型结冷胶样品，在40℃时，用光散射法、特性黏度法研究了相对分子质量对25 mM氯化钠水溶液中凝胶螺旋转变的影响。建立了直接显示浸没在盐溶液中的块状凝胶表面的原子力显微镜方法，并成功地应用于含氯化钾或氯化铯的凝胶。含CaCl2颗粒凝胶(PG-CaCl2)的断裂应力和储存杨氏模数随PG-CaCl2含量的增加而增加，而含有PG-CaCl2的MG-CaCl2的断裂应力和储存杨氏模数随PG-CaCl2含量的增加而减小。预计结冷胶可以作为吞咽困难人群的质地修饰剂。

By means of static and dynamic light scattering and viscosity measurements for the series of fractionated gellan samples, chain rigidity of gellan molecules was evaluated quantitatively both at the ordered and disordered states, and the fundamentals of gel structure was characterized.Using 6 sodium-type gellan gum samples, M_w=12x10^4〜1.7x10^4 at 40℃, we investigated the effects of molecular weight on the coil-helix transition in aqueous solutions with 25 mM NaCl by light scattering, intrinsic viscosity, and circular dichroism measurements and differential scanning calorimetry.Atomic force microscopy protocols for directly visualizing a bulk gel surface submerged in an aqueous salt solution have been established and successfully applied to gellan gum gels containing potassium or cesium chloride.Breaking stress and storage Young's modulus of gellan gels (MG) containing particle gellan gels containing CaCl_2 (PG-CaCl_2) increased with increasing PG-CaCl_2 content, while those of MG-CaCl_2 containing PG-CaCl_2 decreased.Gellan gel containing barium sulfate formed bolus with better consistency than that of agar and gelatin gels. It is expected that gellan can be used as a texture modifier for people with difficulty in swallowing.