The Dairy Science and Food Technology website contains several free, On Line calculators, for determining the cumulative lethality (F, B*, P or PU) of thermal processes, the concentration of Thermal Process Indicators (TTI) following UHT treatment of milk and several other process indicators.
These calculators are listed on the Calculators and Models page under Thermal Processing e.g.
- Calculator for determining the lethality (F, value) of a thermal process using the Trapezoid and Simpson's rules. This unique calculator works with thousands of pasted values e.g. from a data logger.
- Calculator for determining the lethality (F, B* values) and chemical changes (C* value, formation of HMF, Lactulose, Furosine, and destruction of thiamine) in heated milk integrated using the Trapezoid and Simpson's rules.
- Calculator for determining the lethality (F, B* values) and chemical changes (C* value) for generic high-temperature processes using the Trapezoid and Simpson's rules.
- Determine the accuracy of 3 algorithms for predicting the concentration of lactulose in milk after defined heat treatment.
The lethality calculators convert temperature readings to lethal rates, plot the lethal rates against time, and determine appropriate lethality values or chemical indicators for a heat process whether using hot water, saturated steam or dry heat. The area under the time-lethality curve is determined by numerical integration using the industry standard method, the trapezoid rule or the more accurate Simpson's rules or both for comparative purposes. In general, the more values, the more accurate the value for F or P will be. One of the calculators will also upload CSV files of a thermal process and provides a facility for free, independent validation of a thermal process.