Jump to content

  • Quick Navigation
Photo
  • You cannot start a new topic
  • Please log in to reply
3 replies to this topic

#1 clover

clover

    Grade - MIFSQN

  • IFSQN Member
  • 77 posts
  • 5 thanks
2
Neutral

  • Earth
    Earth

Posted 04 May 2016 - 07:18 AM

Hi all,

 

I’m not a microbiologist and establishing micro test parameters + specs is a new thing for me.......hence, could someone from this area of expertise or experience kindly refer to the table below and let me know how could the test parameters + specifications be made more comprehensive enough to accurately reflect the microbiological safety of finished product (mainly cooked food) such as soups, dressings, sauces, pastries, pastas, risottos, cheeses, confit, meat..?

 

Also, would be great if someone could highlight the difference and the significance of “Total Coliform Count vs Faecal Coliform Count" . 

 

Food Test

Total Aerobic Plate Count

Not more than 100 000 CFU/g

Total Coliform Count

No guideline

Faecal Coliform Count

< 3.0 MPN/g

Staph. Aureus

Not detected per g

 

Ice & Water Test

Total Aerobic Plate Count

Not more than 100 000 CFU/g

Total Coliform Count

<1 per 100ml

Total E.Coli Count

<1 per 100ml

 

Equipment Swab

Total Aerobic Plate Count

Not more than 100 CFU/ml

Total Coliform Count

<1 CFU/ml

Total E.Coli Count

Absent per swab

 

Hand Swab

Total Aerobic Plate Count

Not more than 100 CFU/ml

Staph. Aureus

Absent per swab

 

Thank you in advance.

 



#2 Charles.C

Charles.C

    Grade - FIFSQN

  • IFSQN Moderator
  • 17,393 posts
  • 4841 thanks
945
Excellent

  • Earth
    Earth
  • Gender:Male
  • Interests:SF
    TV
    Movies

Posted 04 May 2016 - 08:37 AM

Hi all,

 

I’m not a microbiologist and establishing micro test parameters + specs is a new thing for me.......hence, could someone from this area of expertise or experience kindly refer to the table below and let me know how could the test parameters + specifications be made more comprehensive enough to accurately reflect the microbiological safety of finished product (mainly cooked food) such as soups, dressings, sauces, pastries, pastas, risottos, cheeses, confit, meat..?

 

Also, would be great if someone could highlight the difference and the significance of “Total Coliform Count vs Faecal Coliform Count" . 

 

Food Test

Total Aerobic Plate Count

Not more than 100 000 CFU/g Not unusual

Total Coliform Count

No guideline < 100 cfu/g

Faecal Coliform Count Unreliable, best avoided IMO. Use E.coli instead, <10cfu/g

< 3.0 MPN/g

Staph. Aureus

Not detected per g <10cfu/g

 

Ice & Water Test

Total Aerobic Plate Count

Not more than 100 000 CFU/g High

Total Coliform Count

<1 per 100ml Typical, usually means undetected

Total E.Coli Count

<1 per 100ml Typical, usually means undetected

 

Equipment Swab Need knowledge of area swabbed/dilution procedure for further interpretation of data

Total Aerobic Plate Count

Not more than 100 CFU/ml

Total Coliform Count

<1 CFU/ml

Total E.Coli Count

Absent per swab

 

Hand Swab Need knowledge of area swabbed/dilution procedure for further interpretation of data

Total Aerobic Plate Count

Not more than 100 CFU/ml

Staph. Aureus

Absent per swab

 

Thank you in advance.

 

Hi Clover,

 

Some comments above. I have added a few typical levels but note that limits for all the above can vary widely (up and down) with source, product etc Micro.data is notoriously inaccurate/variable.

 

None of the terms TAPC, TCC, E.coli are directly associated with safety.

S.aureus coag. positive is safety-related.

Faecal Coliform count is sort of obsolete although some people still use it. From memory, was intended to offer a  fast method to estimate E.coli. IMO unreliable and not recommended to use, better to use E.coli.


Kind Regards,

 

Charles.C


Thanked by 1 Member:

#3 clover

clover

    Grade - MIFSQN

  • IFSQN Member
  • 77 posts
  • 5 thanks
2
Neutral

  • Earth
    Earth

Posted 04 May 2016 - 10:21 AM

Hi Charles, 

 

I'm so sorry that the table didn't turn out nicely! I'm not sure why but I actually used the "Paste From Word" button to copy paste the table so that viewers are able to view it with ease. Apologize for that glitch and thank you so very much. I'm happy to get some insight on the typical levels. 

 

I agree with Faecal Coliform being obsolete but I need to provide some justification as to why it's unreliable and hence should be replaced with E.coli count. Any journal/book/article more info on this would be good. 

 

Need knowledge of area swabbed/dilution procedure for further interpretation of data

 

Equipment swab (e.g meat slicer, onion dicer, knifes, table tops preparation area, chopping board, spoon..anything in contact with cooked/raw food) 

Hand swab (Swabbing is done on-site, inside kitchen right after workers washed w soap, wipe with tissue and sanitize their hands - no drying..swab only a hand, not a pair of hands, in between fingers, inside and on top of palms)

 

Sorry, I'm not sure what do you mean by dilution procedure as our samples will then be sent to external third party lab to conduct the test. We basically use a sterile swab tube to do both eq and hand swab. I presume that the lab would then pour & spread the liquid in the swab tube on an agar and incubate. Is it appropriate for me to ask how they interpret their data? Cos the numbers don't mean anything to me unless I know what it represents....

 

 

Hi Clover,

 

Some comments above. I have added a few typical levels but note that limits for all the above can vary widely (up and down) with source, product etc Micro.data is notoriously inaccurate/variable.

 

None of the terms TAPC, TCC, E.coli are directly associated with safety.

S.aureus coag. positive is safety-related.

Faecal Coliform count is sort of obsolete although some people still use it. From memory, was intended to offer a  fast method to estimate E.coli. IMO unreliable and not recommended to use, better to use E.coli.



#4 Charles.C

Charles.C

    Grade - FIFSQN

  • IFSQN Moderator
  • 17,393 posts
  • 4841 thanks
945
Excellent

  • Earth
    Earth
  • Gender:Male
  • Interests:SF
    TV
    Movies

Posted 04 May 2016 - 11:36 AM

Hi Clover,

 

For equipment swab counts, the usual procedure is to swab a defined area Acm2, eg 10cm x 10cm (ie 100cm2)

 

The swab is usually immersed in X ml of a liquid that comes with the test kit and then sent to ext. lab.

 

The external lab usually (but not always) take 1ml of  X, plate it and report the plate count. But occasionally they dilute a portion first and report the result for this diluted portion, or use a volume other than 1ml. They should internally calculate/report a  result (Wcfu) which would be equivalent to the total  initial received volume Xml. But labs sometimes only report the result for 1ml of X without noting it. Or other strange numbers.

 

Assuming you know A and W, the result  is then W/A cfu/cm2.

 

If you don’t know A (and/or sometimes X/W) it’s not possible to compare yr  result to general published limits and the result is only useful for internal comparisons.

 

Can see these 2 threads if you wish to see more practical  details -

 

http://www.ifsqn.com...equipment-swab/

 

http://www.ifsqn.com...other-surfaces/

 

Regarding Faecal Coliform, try these refs –

 

Attached File  fc1 - The Fallacious Fecal Coliform (IAFP's 12th European Symposium on Food Safety).pdf   222.45KB   39 downloads

Attached File  fc2 - Comparison of thermotolerant coliforms and Escherichia coli densities in freshwater bodies.pdf   147.69KB   29 downloads

 

Regarding interpretation of swabbed surfaces -

 

http://www.ifsqn.com...ces/#entry60958


Kind Regards,

 

Charles.C






Also tagged with one or more of these keywords: microbiological, test parameters, pathogens, total aerobic plate count, total coliform count, faecal coliform, vibrio, cholera, salmonella, clostridium

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

EV SSL Certificate