Simulating Temperature versus Time Relationships in the Thermal Preservation of Foods
The purpose of this set of five Demonstrations is to simulate the lethality of thermal food preservation processes using nonlinear inactivation kinetics. This first Demonstration allows you to choose and change the process's temperature history ("temperature profile") at the coldest point in the treated container. By setting and changing the eight control parameters, you can simulate various thermal processes. Once a temperature profile is created, you can examine the corresponding survival pattern of the targeted organism whose heat resistance parameters can also be manipulated in the other Demonstrations. Notice the automatic scaling of the axis; it is different in each example.
This is the first of five Demonstrations of functions used to model thermal processing of foods for the purpose of eliminating the presence of pathogenic and spoilage microorganisms. The five Demonstrations allow slider-control manipulation of the plots of:
1) an 8-parameter nonlinear "temperature profile", temperature (in degrees C) versus time (in minutes)
2) a 2-parameter nonlinear Weibullian rate, , as a function of temperature (in degrees C)
3) a 10-parameter nonlinear Weibullian rate, , as a function of time (in minutes)
4) an 11-parameter dynamic microbial log survival, , as a function of time (in minutes)
5) a 12-parameter equivalent isothermal time as a function of time (in minutes)
Please note that not all possible parameter combinations yield a realistic temperature profile.
Snapshot 1: fast pasteurization
Snapshot 2: slow pasteurization
Snapshot 3: long sterilization