Monitoring of a critical limit - cooking

Hi

We monitor a CCP of cooking by taking the core temperature at the end of the cooking process. We define in our HACCP what the critical limit is for the core temperature not the cooking process.

When auditors look at our HACCP CCP summary, they appear to have differing views on how the limits should be stated. Some like to see a time limit, some don't.

My question is if we take the core temperature and the limit is > 90 degrees C should we be stating a time that that this 90 degrees should be maintained or not - bearing in mind that it takes a short period for the thermometer probe to stabilise to take a reading.

The process used is a heat treatment to achieve a 90 degrees for 10 mins equivalent to control Clostridium Botulinum.

I have looked at some other HACCP plans which do and don't and need some help to decide which is correct.

Thanks

Hi classic,

 

A little more  info on the overall product / process might be helpful.

How has your process been validated? If it is validated to a 90°C for 10 min Equivalent then as I would see it , once your core temperature reaches 90°C then your limit has been reached and there is no requirement for a time. 

 

I have similar processes and we state a minimum x°C for a minimum of y min. and this has been validated by an external validation consultant. 

 

Now.... as Charles has more or less pointed out, it will depend on the process, is it batch cooking or continuous flow. 

 

My advice is to go back to your validation and see what the cooker is actually validated for, if it not clear then go back to whoever did it and ask the question.

 

Once you find out write it the way that makes sense to you and take your auditors remarks into account. Make sure you understand the validation so you can explain it to someone who doesn't know your process, like an auditor.

Hi classic -

     while we wait for more feeback on your process...you state that you are cooking 'to achieve a 90 degrees for 10 mins equivalent to control Clostridium Botulinum'. If that is the case, it would appear that you should be verifying >90C for 10 minutes in order to meet the standard you are targeting...

 

KTD

Hi

 

If you want to cook the product for a certain time and temp then first you have to wait for your desire temp (CCP) and then time any (CCP)

 

OR send the complete process procedure including all requirements if would be good to review it

 

Thank You 

Hi Classic,

 

Just to put some numbers on the situations detailed in previous posts.

I assume target reduction is 6D and the assumptions as shown in attached table are appropriate to yr product/process.

I will take the simplest case where product core temperature is validatably  constant through the cooking process.

I assume the temperaure monitor display has zero error and = product "core" temperature. (IMEX unlikely in practice in which case validation is involved).

Temperatures (“core”)  in table are for worst case, ie slowest heating unit (eg largest size) / least accessible internal location.

For 6D the equivalent T vs t values to 90degC/10min  are shown in the Table, eg 91 degC requires a  minimum time of  7.9 min.

So the critical limit would be >=91degC @ 7.9min (usually easiest to fix the time)

(IMEX assuming for example a constant 7.9 min conveyor system in/out time,  it is customary to set an operational minimum temperature limit at, say, 92 degC to avoid failing the critical limit and therefore triggering corrective actions).

 

The core temperature such that  a time value would be “instantaneous” and therefore redundant  is  >> 100degC (off the chart).

 

If product "core" temperature is not uniform through the cooking process, some more complicated validations will likely be necessary. Excel spreadsheets are available for this as detailed elsewhere on this forum.

 

lethal rates C.botulinum.pdf   167.46KB   73 downloads

Unfortunately I can't give full details of the product as this would identify the company and I can't do that.

However, I can tell you that the process is batch, a rack of product all uniform in size is placed in a steamer cooker. Once the air temperature in the steamer is up to the required temperature a timer starts and the product remains in the steamer until this time has elapsed. The process has been validated by placing data loggers in the product and the data downloaded from the data logger is a 90/10 equivalent. The steamer has probes linked into an electronic monitoring system so we have a graph of the air temperature at 4 points in the steamer. This has also been validated using data loggers in product. Once the product has been removed we then check core temperature of the product with a verified probe and must be > than 90 C.

All I want to know is what to record in the HACCP documentation

Thanks

Unfortunately I can't give full details of the product as this would identify the company and I can't do that.

However, I can tell you that the process is batch, a rack of product all uniform in size is placed in a steamer cooker.

Once the air temperature in the steamer is up to the required temperature a timer starts and the product remains in the steamer until this time has elapsed.

The process has been validated by placing data loggers in the product and the data downloaded from the data logger is a 90/10 equivalent.

The steamer has probes linked into an electronic monitoring system so we have a graph of the air temperature at 4 points in the steamer. This has also been validated using data loggers in product.

Once the product has been removed we then check core temperature of the product with a verified probe and must be > than 90 C.

All I want to know is what to record in the HACCP documentation

Thanks

 

Hi Classic,

 

Once the product has been removed we then check core temperature of the product with a verified probe and must be > than 90 C.

This only proves that the exit temperature is > 90degC

 

The key items to validate in the context of previous post are (1) The product core temperature/time profile  for the cooking process  and  (2) the correlation between monitored temperature and product core temperature.

 

The critical limits must include a temperature and a time unless the time is acceptably close to zero.

 

i don't quite understand yr problem. Perhaps you can give an alternative example to explain.

All I want to know is what to record in the HACCP documentation

Thanks

 

It's all Greek to me. :headhurts:

 

 

It's all Greek to me. :headhurts:

 

If classic is happy with the process can somebody please just answer her HACCP documentation query.

 

Thanks,
Simon

 

 

Hi Simon,

 

I thought i just gave that info.

 

But admittedly not in Greek.

Hi simon

Assuming with "HACCP documentation" you mean the HACCP plan then proceed as follows in the procedure column; state "place the product in the steamer and heat. When temperature reaches 100^oC Hold for 10 min. Remove and confirm product core temperature at exit is >90^oC"

It is ultimately a question of target bacterial reduction and the necessary thermal lethality to achieve that reduction.

So for a given reduction, eg 6D, and assuming that the temperature is constant, the critical limits are simply the T/t combinations given in a 6D Lethality table.

The temperatures given are assumed to be those at the slowest heated location.

If the temperature is varying with time, an integrated calculation for total lethality will be required to fix the critical limits unless the next line applies.

It is common to assume that when the time in the table reaches a few seconds, it can be equated to "instantaneous".

Soooo, the answer to the OP is YES.

Hi there, Are there any thermal equivalents above 100°C?

In some European countries there are ''industry HACCP plans''. Which are generally accepted by auditors and authorities.
You could check if the UK also has these standards for the product type you are making.

 

I used to work in the ready meal industry. And there was a industry standard that a core temperature of 75°C should be reached during cooking.
We would also record the product temperature at the end of cooking, if it was >75°C it was good to go.

We could always refer back to the industry HACCP standard and this was always accepted.

Of course the above mentioned is correct. The reduction 6 log (6D) should be desired, and that could mean a whole slew of time/temperature variants.
I am pretty sure that the time for 6 log reduction at 90°C is quite short. So you can also validate your process that way.
 

Hi Marloes,

Thank you. Unfortunately I work in milk/ dairy and its an incidental MAP there are no standard ones.

As Nitrogen is used to aid when forming cartons and as such there is a potential for an anaerobic environment.

Therefore, we need to achieve the equivalent of 90°C for 10 minutes.

 

I have found a further equivalent at 100°C for 1 minuet. 

 

I was hoping someone may know of higher thermal equivalents to achieve the 6 log reduction?

Are you treating liquid milk or another dairy product?