热凝胶在碱溶过程的流变学和质构学行为分析

Rheological and texture behavior analysis of curdlan during alkaline dissolution process

碱溶过程是影响热凝胶提取工艺效率和产品质量的关键因素。为探寻适合工业化提取热凝胶的工艺条件,研究了碱处理时间、碱溶温度和碱浓度对热凝胶溶胶流变学和提取后凝胶产品质构的影响。结果表明,(1)随着碱处理时间的延长,溶胶黏度降低,稠度系数下降,流变指数增加,溶胶接近于牛顿型流体,凝胶强度基本不变;(2)热凝胶凝胶强度和溶胶黏度均随碱溶温度升高而下降,较高的温度处理会降低热凝胶的品质,室温或水冷环境下可以满足工业要求;(3)随着碱浓度的增加,流体流变行为从宾汉塑性流体向牛顿流体接近。碱浓度低于0. 3 mol/L时碱浓度明显影响溶胶流体性质,碱浓度高于0. 5 mol/L时碱浓度明显影响热凝胶品质。

Alkaline dissolution is a key factor affecting the curdlan separation efficiency and product quality.In order to explore the optimal conditions for commercial production of curdlan,the effects of alkaline dissolution time,alkaline dissolution temperature and concentration of alkali solution on the rheological properties of curdlan colloidal sol and gel texture were studied.The results showed that,(1)With the prolongation of alkaline treatment time,the viscosity of the colloidal sol decreased,consistency coefficient decreased,rheological index increased.The colloidal sol is closed to Newtonian fluid,and gel strength remains unchanged.(2)Both gel strength and colloidal sol viscosity of curdlan decreased as the increase of alkaline dissolution temperature,and higher temperature treatments reduced the quality of curdlan.Room temperature or water-cool condition can meet industrial requirements.(3)As alkaline concentration increased,fluid rheological behavior of curdlan changed from Binham plastic fluid to Newtonian fluid.When alkaline concentration was lower than 0.3 mol/L,it significantly influenced colloidal sol properties.When higher than 0.5 mol/L,alkaline concentration significantly affected quality of curdlan.