Measurement of milk clotting activity by rotational viscometry.
Measurement of milk clotting activity by rotational viscometry.
复制标题
通过旋转粘度测定法测量乳汁凝固活性。
作者：
Mandy Jacob;Martin Schmidt;D. Jaros;H. Rohm
测定乳凝剂活性的标准方法是旋转瓶法，其中凝结时间定义为目视可观察到的絮凝开始的时间。本研究的目的是验证是否可以通过旋转粘度测定法确定乳汁凝固时间。使用三种不同的混凝剂和不同pH和温度的复原奶，测定了稳态剪切下的絮凝时间和粘度，并通过小振幅振荡剪切流变仪监测了牛奶凝胶化。结果表明，与pH和温度无关，乳汁凝固时间与表观粘度7.24±0.45 mPa.s有关，表明旋转粘度法可用于絮凝时间的筛选，准确度约为6%。
Standard method for the determination of the activity of milk coagulants is the rotating bottle method, where clotting time is defined as the time when visually observable flocculation starts. Aim of this study was to verify whether it is possible to determine milk clotting time by rotational viscometry. Using three different coagulants and reconstituted milk of different pH and temperature, flocculation time and viscosity in steady shear was determined, and milk gelation was monitored by small amplitude oscillating shear rheometry. The results show that, independent of pH and temperature, milk clotting time is related to an apparent viscosity of 7.24±0.45 mPa.s, indicating that rotational viscometry can be used for the screening of flocculation time with an accuracy of approximately 6%.