Hi everyone,
I am looking for resources to understand time/temperature processing and how it relates to pathogen growth and inactivation. I understand it depends on the medium (e.g., water activity), but wanted to get a general sense.
FDA has their HARPC Draft Guidance which includes Appendix 3: Bacterial Pathogen Growth and Inactivation. The only thing is... I'm not sure if my understanding of the tables is correct!
Table 3A - the guidance states it "contains information on the minimum water activity (aw), minimum and maximum pH, and minimum and maximum temperatures that limit growth for the bacterial pathogens that are of greatest concern in food processing". Am I correct to understand that these are the conditions that the pathogens listed can grow at? For example, Bacillus cereus cannot grow when water activity < 0.92, outside the pH of 4.3 - 9.3, or outside the temperatures of 39.2 - 131F?
Table 3B - Time and Temperature Guidance for Controlling Pathogen Growth and Toxin Formation in Food Products - the guidance states it "contains information on maximum cumulative exposure time at internal product temperature ranges for exposure of foods that, under ordinary circumstances, will be safe for the bacterial pathogens that are of greatest concern in food processing. These maximum, cumulative exposure times are derived from published scientific information". This table confuses me because the highest product temperature listed is above 70F. But I would expect the exposure time would differ if it's 90F vs. 170F? But they don't account for that.
Some context - I'm trying to look for literature concerning dehydration of fruits that would constitute a kill step. The process I'm looking at dehydrates at 80C for several hours. I know a validation study should be carried out to, but I'm curious if there's already literature that shows general time/temperature inactivation dynamics of pathogens. So if you have any to share, please do!