Salmonella how does it get there?

Hi All

I am due to do a HACCP 4 course  whih includes microbiology, Micro is something i am not too good with!

I have been asked to do some pre course work about diced chicken (which is not my area as i deal with low risk foods).

Short scenario:

Frozen raw chicken is bought in and stored at -18oC. It is then defrosed in a temper chill over 24 hours with a core temp of no more than 5oC. The chicken is then minced and and placed into a mixer with dextrose, salt and modified starch and mixed for 1 hour (there is more to the process but this is the section i am struggling with).

We have been given the following answers:

A hazard for intake of the chicken is - salmonella present on intake and the control would be a C of A, reputable suppliers etc.

A hazard in the temper chill is - salmonella growth due to incorrect defrost temperature and the control would be effective temperature control.

A hazard on mixing is - salmonella growth due to too long in the mixer and the control is correct time control when mixing

I understand the controls for these but i dont understand how some of the hazards get there in the first place! If your product is bought in free from salmonella and you have a C of A to prove it, how then would you get salmonella growth in the chiller or at the mixing stage?

Hope someone can help!

Many thanks

Whitney

Salmonella is a naturally occurring organism on poultry and, as such, needs to be considered probable to occur on raw chicken even in light of the COA and testing process.  While the testing program can help build your confidence in the supplier's control methods the only way to guarantee all the product is free from the pathogen would be to test all the product - then there would be nothing to manufacture. I am not as familiar with regulatory requirements in the UK but would note that raw poultry testing standards in the US requires < 10% to prevent regulatory action.  Until 2011this level was 21%.

From a HACCP standpoint you would want to identify the risk on incoming materials but would note both the materials testing program as well as the further control measures further down the line.  The COA program would affect your rating in the reasonably likely to occur.  You could use the past history of the supplier to rate this and, if results are consistent, you might consider it less likely to occur.

You would also use your existing internal programs to rate the hazard as less likely to occur in subsequent steps.  The important exercise is that you are documenting that you have considered the hazard.

Hope this helps.

Susan Ranck

Dear whitney,

Your question illustrates a popular characteristic of microbiological CoAs - the terms free, absent, not detected are frequently used as synonyms for zero occurrence of the pathogen in the batch. The particular choice may be dictated by local legislatory requirements  but, as noted in previous post, all such "tags" are numerically limited by statistical (and analytical) considerations in respect to sampling and measurement.

I think you will find that the UK tolerance situation for Salmonella in, for example, frozen retail raw chicken portions is comparable to USA. And similarly for eggs.

Rgds / Charles.C

Dear Whitney,

Even COA would be given from a reputable supplier would not gurantee that all the checken has zero count, terms used as free, absent is in certain prespective of an approved method with certian confidence level 9mostly 95%). Secondly it is based on results collected from samples. It is not 100% testing of every piece. So there is a probability that certain number of chicken contain some units of salmonella which can grow at later stages. 

As mentioned by susan, you should list this hazard as it is probable. Then you can rank it as per history and confidence level to the supplier. You can even crosscheck the COA by testing at your site and make analysis for ranking the risk.

THANKS SO MUCH EVERYONE X