What measure defines the temperature increase needed for a 10-fold decrease in microorganism death time?

The measure that defines the temperature increase needed for a 10-fold decrease in microorganism death time is the Z-value. This parameter is essential in thermal processing as it quantifies the sensitivity of a microorganism to temperature changes. Specifically, a Z-value indicates the temperature change required to reduce the D-value, which is the time necessary at a specific temperature to achieve a one-log reduction in microbial populations, by a factor of ten.

For instance, if a particular microorganism has a D-value of 5 minutes at 60°C, increasing the temperature to 65°C might reduce the D-value to 0.5 minutes if the Z-value is 5°C. This illustrates how the Z-value is critical in determining how effectively heat can be used to control pathogens in food products. Understanding Z-values aids in designing thermal processes to ensure food safety by achieving adequate heat treatment.