Borda D, Smout C, Van Loey A, Hendrickx M
Department of Food Bioengineering, Faculty of Food Science and Engineering, University Dunarea de Jos, 800201, Galati, Romania.
J Dairy Sci. 2004 Aug;87(8):2351-8. doi: 10.3168/jds.S0022-0302(04)73357-3.
A crude plasmin extract was prepared from milk by ultracentrifugation and was partially purified using ammonium sulfate precipitation. Isothermal and high-pressure inactivation of this plasmin system at pH 6.7 could be described by a first-order kinetic model. As expected, the plasmin system displayed a high thermostability. High-pressure treatments were conducted in the 300- to 800-MPa pressure range, combined with temperatures from 25 to 65 degrees C. The plasmin system was very pressure stable at room temperature, but inactivation occurred with combined high-pressure/temperature-treatments. The influence of temperature at different constant pressures on the inactivation rate constant was quantified using the Arrhenius equation. At all temperatures studied, a synergistic effect of temperature and high pressure was observed in the 300- to 600-MPa pressure range. However, an antagonistic effect of temperature and pressure appeared at pressures above 600 MPa.
通过超速离心从牛奶中制备粗纤溶酶提取物，并使用硫酸铵沉淀进行部分纯化。该纤溶酶系统在pH 6.7时的等温及高压失活可用一级动力学模型描述。正如预期的那样，纤溶酶系统表现出很高的热稳定性。在300至800 MPa的压力范围内进行高压处理，并结合25至65摄氏度的温度。纤溶酶系统在室温下对压力非常稳定，但在高压/温度联合处理时会发生失活。使用阿伦尼乌斯方程量化了不同恒定压力下温度对失活速率常数的影响。在所有研究温度下，在300至600 MPa的压力范围内观察到温度和高压的协同效应。然而，在压力高于600 MPa时出现了温度和压力的拮抗效应。
