摘要
以酸乳为研究对象,建立了通过稳态剪切应力扫描评价酸乳特性的测试方法。对9种市面上流行的酸乳(包括7种类固体酸乳与2种饮用型酸乳)进行稳态剪切应力扫描,结果表明:酸乳具有明显的剪切稀化现象,另外,通过黏度曲线上极低剪切速率下的黏度可以用来评价酸乳的零剪切黏度,形变-剪切应力曲线中形变发生明显变化时所对应的剪切应力可以表征酸乳的屈服应力,对于饮用型酸乳则无屈服应力的存在。对方法的试验参数也进行了优化,研究了上样后不同平衡时间对黏度测定的影响,以及试验测试时达到稳态条件所需的最长时间。
In this paper, a method for determination of evaluation of yoghurt properties by shear stress sweep under the steady state was established. The experiments of shear stress sweep on the 9 kinds of popular yogurts on the market including 7 solid-like yoghurts and 2 drinking-type yoghurts were tested. The results showed that yoghurt had obvious phenomenon of shear thinning, in addition, the viscosity at the extremely low shear rate on the viscosity curve could be used to evaluate the zero-shearing viscosity and the shear stress where strain was changed obviously on the strain-stress curve could be used to characterize the yield stress of yoghurt, while for drinking-type yoghurt there existed no yield stress. Meanwhile the experimental parameters of the method were optimized in this paper. The effect of different equilibrium time after loading the sample before test on the viscosity as well as the maximum time needed for steady state were studied.
作者
吴伟都
朱慧
欧凯
王雅琼
李言郡
WU Wei-du;ZHU Hui;OU Kai;WANG Ya-qiong;LI Yan-jun(Hangzhou Wahaha Group Company Limited and Key Laboratory of Food and Biologica Engineering of Zhejiang Province,Hangzhou 310018)
出处
《食品科技》
CAS
北大核心
2018年第9期100-103,共4页
Food Science and Technology
基金
2018年浙江省分析测试科技计划项目(2018C37040)
关键词
酸乳
稳态
流变特性
剪切应力扫描
yoghurt
steady state
rheological properties
shear stress sweep