Oil Roasting Validation Study
When receiving validation for an oil roasting process. The validation study mentions a time and a temperature for a 5 log reduction of pathogens, would I be wrong to interpret that as an accumulation of time at a given temperature rather than a continuous amount of time at that temperature?
Say the study states that to achieve the 5 log reduction, I must roast the product for 240 seconds at 200 degrees F, meeting all other criteria, to be considered a successful roast.
If I am taking temperature measurements every second and recording that information digitally, do I need to reset the timer anytime that temperature drops below 200 degrees, or can I justify an accumulation of time over 200 degrees?
ex.
#1. I drop the basket and the temperature drops below 200 (not recording time 0.00). Once it hits 200 my timer begins recording (75 seconds). It dips below 200 and my timer turns off (75 seconds). Once it heats back up to 200 the timer begins recording the time from where it was (75 seconds). Once I record a total of 240 seconds above 200 degrees my timer sounds to notify me I have completed the process.
#2. I drop the basket and the temperature drops below 200 (not recording time 0.00). Once it hits 200 my timer begins recording (75 seconds). It dips below 200 and my timer turns off and resets (0 seconds). Once it heat back up to 200 the timer now starts recording again (1. 2. 3. 4.) Once I record 240 continuous seconds above 200 degrees my timer sounds to notify me I have completed the process.
When receiving validation for an oil roasting process. The validation study mentions a time and a temperature for a 5 log reduction of pathogens, would I be wrong to interpret that as an accumulation of time at a given temperature rather than a continuous amount of time at that temperature?
Say the study states that to achieve the 5 log reduction, I must roast the product for 240 seconds at 200 degrees F, meeting all other criteria, to be considered a successful roast.
If I am taking temperature measurements every second and recording that information digitally, do I need to reset the timer anytime that temperature drops below 200 degrees, or can I justify an accumulation of time over 200 degrees?
ex.
#1. I drop the basket and the temperature drops below 200 (not recording time 0.00). Once it hits 200 my timer begins recording (75 seconds). It dips below 200 and my timer turns off (75 seconds). Once it heats back up to 200 the timer begins recording the time from where it was (75 seconds). Once I record a total of 240 seconds above 200 degrees my timer sounds to notify me I have completed the process.
#2. I drop the basket and the temperature drops below 200 (not recording time 0.00). Once it hits 200 my timer begins recording (75 seconds). It dips below 200 and my timer turns off and resets (0 seconds). Once it heat back up to 200 the timer now starts recording again (1. 2. 3. 4.) Once I record 240 continuous seconds above 200 degrees my timer sounds to notify me I have completed the process.
Hi CCC,
This topic (lethality) is discussed in text books and previous posts here.
You basically need to estimate the lethality of the process by integrating the area under the plot of temperature versus time. The result enables calculation of log reduction. Programs are available, eg see -