International journal of food science and technology vol:27 issue:1 pages:21-31
In this work, a general theory for the development of a Time Temperature Integrator, TTI-system, is outlined. A z-value (or activation energy) of the TTI-system equal to that of target index is crucial for the usefulness of a system to monitor the impact of thermal processes on foods. The proposed TTI, namely the heat-stable fraction of peroxidase covalently immobilized on porous glass beads in dodecane, can be used to indicate the intensity of a delivered pasteurization process when a z-value of 10-degrees-C is used for calculating the lethality. Lethalities read from the bio-indicator showed excellent agreement with those integrated from the measured time-temperature data.