低酰基结冷胶-乳清蛋白混合凝胶的凝胶特性

Gelation Properties of Low Acyl Gellan-Whey Protein Mixed Gels

研究了离子种类、离子浓度和基体浓度对低酰基结冷胶/乳清蛋白混合凝胶力学性质、保水性质、光学性质和网络孔径的影响。研究发现,乳清蛋白浓度对混合凝胶凝胶特性影响较小。混合凝胶的断裂应力、断裂应变、不透明性和保水性随着低酰基结冷胶浓度的增大而增大,混合凝胶网络孔径则随着低酰基结冷胶浓度的增大而减小。离子种类和离子浓度对混合凝胶凝胶特性影响显著,混合凝胶的断裂应力和孔径随着离子浓度的增加出现了先增大后降低的变化趋势,断裂应变和保水性则随着离子浓度的增大而减小。离子浓度增大,混合凝胶的不透明指数随之升高,当离子浓度超过某一定值后,不透明指数则基本保持恒定。相对于钠离子而言,钙离子形成的凝胶更强且用量更少。钠离子和钙离子在诱导凝胶形成上不存在协同效应。

The effects of ion type, ion concentration and polymer concentration on the mechanical properties, water-holding capacities, optical properties and pore size of low acyl geUan-whey protein mixed gels were investigated. The results showed that whey protein concentrations had little effect on the gelation properties of mixed gels. With the increase of low acyl gellan concenwations, the fracture stress, fracture strain, opacity index and water holding capacity increased, while the pore size decreased. Moreover, ion type and ion concentration affected the gelation properties of mixed gels significantly. Furthermore, the fracture stress and pore size increased with the increasing ion concentrations tmtil ions reached a critical level, and then decreased after the concentration exceeded the critical level. The fracture strain and water holding capacity decreased with the increase of ion concentration. The opacity index of the mixed gel increased with the increase of the ion concentration, and the opacity index remained constant when the ion concentration exceeded a certain value. At optimum cation levels, gels with Ca^2＋ were stronger and firmer than gels with Na＋. No synergistic effect between Na^＋ and Ca^2 was found ＋ in inducing gel formation.