10 replies to this topic

[a_andhika]

Dear Forum,

Could you help me to provide literature that mention which average temperature (and time) that may kill all pathogenic microorganisms? (e.g. Salmonella, S. aureus, V. cholera, E. coli) I've found some of them at quick search, but not satisfy me enough. Help me please. Thank you.

Regards,


Arya

[moo73steve]

Hi Arya,

I have quite a few different text books that I have utilised, but here is a copy of a document I have come across that you may like. It is from the "World Food Safety Guidlines for the airline catering industry" 2nd Version, September 2006. It includes the CCP limits and the original references used to obtain them.

Hope this helps you.

Thanks
Steve

Attached Files

•  Cook_Temperature_Validation.pdf   94.15KB   530 downloads

[a_andhika]

Dear Steve,

Thank you very much Steve, I am really appreciate it. It's more than just helps me:) Once again, thank you.

Regards,


Arya

[Jean]

Hi Arya,

I have quite a few different text books that I have utilised, but here is a copy of a document I have come across that you may like. It is from the "World Food Safety Guidlines for the airline catering industry" 2nd Version, September 2006. It includes the CCP limits and the original references used to obtain them.

Hope this helps you.

Thanks
Steve

Hi Steve,

A good reference.

[Charles.C]

Dear Arya,

The fact is that yr question is rather unanswerable in a general form as I'm sure you already knew. It is unfortunately also often unanswerable in a specific case unless a regulatory situation exists. Similar problem to the infamous microbiological specifications.

One of the most common general approaches is to take a worst case scenario, eg the most difficult species to destroy within the typical flora for the type of product involved but even here, the criteria for "destroy" will vary and are often not spelled out, eg how many log reductions are required ?

Nonetheless, it's an interesting topic to discuss

Rgds / Charles.C

added - Steve's document is interesting but I am a bit cautious regarding the data, eg V.parahaemolyticus is apparently considered the most difficult species to kill for shellfish/crustaceans. I think this is incorrect, seem to remember that V.para is actually considered relatively easy to kill (in the sense of 1D reduction at a given temperature). Most commonly (but not invariably) in EU, I have seen L.monocytogenes selected with minimum 70degC / 2min or equivalent as a reference cooking parameter. Again, you need the actual matrix / data / basis of comparison. However, I suspect this L.mono criterion is not typically used in USA ( ).

added2 - one interpretational reason for a difference in approach is possibly explained in the uploaded initial document in this thread - http://www.ifsqn.com...?showtopic=1080

[a_andhika]

Dear Charles,

I dont think I was so complicated like that (am I? ).

A very good intuition, how many bacterias must be killed to get a "destroy" criteria? IMO, literature from Steve is very good, indeed, at least it can solve my problem. I think the "destroy" definition much more alike: "How much time and temperature needed to reduce pathogenic bacteria until it reach acceptable limits (which may vary among bacterias)". So the approach I guess not from how many bacterias killed, but from how many bacterias left?

Another opinion, I think the pathogenic microorganisms is not the main problems. Their heat-resistence spore and deadly toxins is the main problems. So, I wouldnt say that a contaminated food would be compeletly safe after treatened on certain time and temperature.

Regards,


Arya

[Charles.C]

Dear Arya,

A very good intuition, how many bacterias must be killed to get a "destroy" criteria?

It's a good question which has generated many books on canning procedures. Hopefully the present recommended methodology is "safe". One approach for some non-canned goods is given in the linked thread above. Unfortunately, words like "completely safe" need rather careful use in the world of probability.

Another opinion, I think the pathogenic microorganisms is not the main problems. Their heat-resistence spore and deadly toxins is the main problems. So, I wouldnt say that a contaminated food would be compeletly safe after treatened on certain time and temperature.

I agree that one needs to "validate' what species is the selected target. This requires defining the exact practical situation / use of worst case scenarios. Generalisations are I fear not that easy and the consequences of an error may be substantial. One example is perhaps the (probably) on-going hamburger story.

Rgds / Charles.C

Added – here is an interesting validation document (2007) for the (stricter) UK time/temp regulations on cooking meat, particularly burgers, as compared to the USA.

 cooking_burgers_et_al_.pdf   178.1KB   157 downloads

[AS NUR]

Another opinion, I think the pathogenic microorganisms is not the main problems. Their heat-resistence spore and deadly toxins is the main problems. So, I wouldnt say that a contaminated food would be compeletly safe after treatened on certain time and temperature.

Regards,


Arya

dear Arya...

Micro interm of Quality and safety decrease is important to control, that the main problems... because spore and toxin can occure when the micro inside of food.. so the best practice is control the micro.

as i know, the micro need water, air, and nutrition to growth.. so dont give them enough water and air especially for the nutritious food like milk, meat etc...... you can do drying process to remove water or pack your food with hermetical package... and the other preservative process..

[a_andhika]

Dear AS Nur,

Yes I agreed with you. Kill the bacteria is the most relevant way, IN ORDER to prevent their growth. But what I mean is we still have to figure out what kind of spore or deadly toxins that may released by them. If the bacteria occurs at significant numbers on a material in a quite long periodic, I think we should consider the toxins too. As far as I am concern, the toxins cannot easily reduced by heating or washing.

Regards,


Arya

[Jean]

To do risk assessment or any challenge tests with micro organisms it is imperative to know about the characteristics of the pathogen being considered for a specific process in a food operations. Among the food pathogenic bacteria only Bacillus and Clostridium form spores and the spores do not cause food poisoning. Therefore controls should be devised to prevent the germination of spores.

Toxin can be heat sensitive or resistant and therefore one has to know which toxin producer has this characteristic. By cooking, using time / temp ratio (based on validated results), can destroy the vegetative cells and heat sensitive toxins. When considering about the heat resistant toxins, the control measures are to avoid germination (in case of spore formers) and rapid multiplication of the vegetative cells due to temperature abuse.



Toxins produced by S.aureus (up to 12 D thermal process) & B .cereus (emetic toxin) are heat resistant.

Cl. botulinum, which produces the potent toxin is heat sensitive and can be inactivated by heating at 80^oC for 10 minutes or boiling for at least 15 minutes.



The toxins produced by Cl.perfringes and C.jejuni are heat sensitive.



Mostly all seafood toxins (DSP, PSP, ASP, NSP, ciguatera) are heat resistant

[a_andhika]

Dear J,

Interesting information. You may also interested to these preference:

FDA's BAD BUG BOOK:
http://www.cfsan.fda...~mow/intro.html

NZFSA's Microbial Pathogen Data Sheets:
http://www.nzfsa.gov...ce/data-sheets/


Regards,

Arya