Log Survival Ratio as a Function of Time
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This fourth of five Demonstrations depicts the microbial log survival ratio, LS, as a function of time (in minutes) for a chosen temperature history. This is done by setting eight temperature profile and three Weibullian heat resistance parameters. Notice the automatic scaling of the axis; it is different in each example.
Contributed by: Mark D. Normand and Micha Peleg (March 2011)
Open content licensed under CC BY-NC-SA
This is the fourth 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 and/or survival curve.
Snapshot 1: pasteurization
Snapshot 2: low temperature sterilization
Snapshot 3: insufficient heat process