【摘要】 研究了浓度、温度、剪切速率、pH和离子浓度对低酰基结冷胶流变行为的影响。结果表明,低酰基结冷胶为典型的切力变稀流体,其表观黏度和剪切速率的关系符合幂律方程。在同一剪切速率下,表观黏度随温度的升高而降低。在同一温度下,结冷胶溶液的表观黏度则随着剪切速率的增加而减小。低酰基结冷胶凝胶强度随着Ca2+和Na+浓度的增加出现先增大后减小的趋势,相对于Na+而言,Ca2+形成的凝胶强度更高,且用量更少。更多还原

【Abstract】 The effects of concentration,temperature,shear rate,pH and cation concentration on rheological behavior of low acyl gellan gum were investigated using rotational rheometer and texture analyzer.Results showed that gellan gum solutions under steady shear possess a shear-thinning fluid(n=0.12～0.49),and the apparent viscosity and shear rate can be expressed in a power-law equation.At the same shear rate,the apparent viscosity was reduced when the temperature increased.At the same temperature,the apparent viscosity was reduced while the shear rate increased.The failure stresses of gellan gels were tested using large compressive deformation until fracture.Maximal true shear stresses represented gel strength.The strength of low acyl gellan gels initially increased with cation concentration,and then decreased with further added cation.It appeared that addition of Ca2+ at low levels results in an increase in gel strength compared to gels with Na+.At same cation levels,gellan gels with Ca2+were stronger than with Na+.更多还原