高酰基结冷胶/酪蛋白酸钠复合凝胶粘弹行为的研究

本文研究了酪蛋白酸钠浓度、结冷胶浓度、离子和测试条件对高酰基结冷胶/酪蛋白酸钠复合凝胶粘弹性的影响。结果表明:高酰基结冷胶/酪蛋白酸钠共混体系为典型的切力变稀流体,表观粘度随着酪蛋白酸钠浓度的升高而降低,而随着阳离子浓度的增大出现先增大后减小的变化趋势。压缩速度对复合凝胶硬度几乎无影响,而内聚性和弹性则随着压缩速度的增加而增大。内聚性随着压缩应变的增大出现先增大后减小的变化趋势。复合凝胶的硬度和弹性随着酪蛋白酸钠浓度的增加而下降,但复合凝胶的内聚性对酪蛋白酸钠浓度不敏感。高酰基结冷胶浓度越高,复合凝胶的硬度和弹性越大。相对于一价离子而言,二价离子形成的凝胶更强且用量更少。钾离子的添加对复合凝胶保水性影响较弱,而钙离子的添加则可以提高复合凝胶的保水性。

Viscoelastic Behavior of High Acyl Gellan/Sodium Caseinate Mixed Gel

The effects of sodium caseinate concentration, high acyl gellan concentration, ion valence (potassium and calcium ions), cation concentration, and test conditions (compression speed and compression strain) on the viscoelasticity of high acyl gellan/sodium caseinate mixed gels were evaluated. The results suggested that high acyl gellan/sodium caseinate mixtures were typical shear-thinning fluids, and the apparent viscosity decreased with increasing high acyl gellan concentration. With increasing cation concentration, the apparent viscosity of mixtures first increased and then decreased. Compression speed had almost no influence on the hardness of mixed gels. Cohesiveness and springiness of mixed gels increased with increased compression speed. The cohesiveness of mixed gels increased to a maximum and then decreased with increasing compression strain. The hardness and springiness of mixed gels decreased with increasing sodium caseinate concentration. The concentration of sodium caseinate had almost no effect on the cohesiveness of mixed gels. The higher the concentration of high acyl gellan, the greater hardness and springiness of mixed gels. The gel formed with divalent ions was stronger and required less material compared with that formed with monovalent ions. The addition of potassium ions had a weak effect on the water-holding capacity of mixed gels, while the addition of calcium ions enhanced the water holding capacity.