Seeking advice on validation of a frying process. We deal in fried products. Basically, thin chips made from dough (flour, eggs, palm oil & other ingredients) are fried at temperatures above 325 degrees F for 2-3 minutes. Internal temperature readings are usually 215 degrees F and water activity less than 0.5. We annually send samples to an independent Lab for APC analysis and the results are always great.
A potential big customer wants us to validate the fry step. We use it as a CCP. We monitor Oil temperature (> 325 F) and dwell time (2-3 minutes). Speed of conveyor belt determines the time the product spends within the oil.
How would you design an experiment to validate this step? Please, anybody with links to scientific literature linking product internal temperature, low water activity to reduced microbial loads in fried products?
Experimental design thoughts: Different sizes of chips, different frying temperature & time combinations. Get results for internal temp, water activity and microbiological analysis.