Validation of Thermal Processes

I listened to a webinar by Adam Borger of the University of Wisconsin-Madison’s Food Research Institute on calculating thermal lethality of microorganisms in foods. In one hour, he did an excellent job of reviewing what I learned in Food Engineering class at the UW (OK, I learned more than that) and applied the information to show how industry can do the math. Have you ever had a process fail, but want to know if the heat was enough to kill? There are spreadsheets publicly available to do the math.

At the end of the talk, Adam referred to validation studies. Is your company one where validation of the kill step has yet to be done? Maybe you do baking, roasting or frying. Under FSMA, companies must have validation of process preventive controls. Our own Matthew Botos here at ConnectFood is a process authority for acidified foods. A process authority is someone who will work with you to validate your process with your product. Legally, manufacturers of acidified and low-acid canned food must use a process authority to validate the thermal process. Process authorities can be found among extension professors, contract labs, and consultants. While writing this blog, I did a search and found listings of process authorities by AFDO by state:

and the Department of Health and Human Services lists four universities in this document:

Only if you are hermetically sealing your product are you required to work with a process authority, internally or externally. Otherwise, validation of your process can be done in many ways. If you can find processing time and temperatures in the scientific literature for your product, you may cite that source. For example, milk pasteurization times and temperatures are published by FDA in the Pasteurized Milk Ordinance. Similar published data may be available for your product. One way to do this search in on Google Scholar; ask a young person about that. After doing a search, you may still need to measure the temperature profile of your product through your process. BEWARE, Peanut Corporation of America, responsible for nine deaths from Salmonella-contaminated peanut butter, had a perfectly good roasting operation that WAS NOT VALIDATED. This is a great example for the need for validation of your process preventive controls.

Get that validation study in your food safety plan. Your FDA inspector will ask to see it.

Dr. Kathy Knutson has food safety expertise in microbiology, hazard analysis, and risk assessment. As a recovering academic, she resides in Green Bay home-of-the-Packers, Wisconsin with her brilliant husband and two handsome sons. Learn more about her consulting services at