Abstract: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.
