High pressure thermal inactivation kinetics of a plasmin system.
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.
Department of Food Bioengineering, Faculty of Food Science and Engineering, University Dunarea de Jos, 800201, Galati, Romania. Daniela.Borda@ugal.ro
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Smout
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Van Loey
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Hendrickx
D000818:Animals; D004789:Enzyme Activation; D004795:Enzyme Stability; D005341:Fibrinolysin / Q000302:isolation & purification / Q000378:metabolism*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008892:Milk / Q000201:enzymology; D011312:Pressure; D013816:Thermodynamics
D005341:Fibrinolysin