15 replies to this topic

[Shuster.35]

Hello All, 

 

I'm trying to determine the correct testing in regards to Listeria for my product. We chop and repackage ready for market, ready for retail Brand-Name cookies. I understand Listeria testing can be performed to the following Levels, if you will. 

 

We can simply detect at a "suspect" level if the enzyme is similar to Listeria. 

 

We can further confirm the suspect sample and get a Positive or Negative result. 

 

Further more we can ask to further test the positive result to determine species. 

 

Can someone validate my thoughts are correct and provide input as to most common/acceptable/realistic testing for the industry? 

 

 

Thanks in advance for your help.  

[FSQA]

 

We can simply detect at a "suspect" level if the enzyme is similar to Listeria. 

How are you going to achieve this? would you like to share the method or equipment you are using for detection?

[mgourley]

I guess my question would be why the concern for listeria?

If you are taking RTE cookies, which have, I would assume been baked, and have a sufficiently low moisture percentage that would not allow Listeria to grow, what is the risk?

Your logic as far as testing is correct, but again, why the need to test the finished product for listeria? The only reason I could think for that is if your processing area is surrounded by floor drains full of listeria or you have roof leaks that are dripping on the finished goods. 

 

Marshall

[Shuster.35]

Testing for Listeria is a requirement of our Customer. They are putting the product into a hard pack retail ice cream. 

 

All our our testing is done by an outside lab using the Genus Listeria ELFA Method. 

[Scampi]

I agree with Marshall........finished goods testing for this commodity doesn't make a lot of sense. Better ways to use those resource $$$

[mgourley]

Well, in that case, I hope it's not Blue Bell   
If the customer requires it, and you wish to provide the product to the customer, then I guess you have to do what they want.
Your testing logic is correct. But I bet they will want all product placed on hold, not to be released until actual Listeria testing comes back negative. I doubt if they are requiring Listeria testing for low moisture foods, they will accept a test for an indicator organism.

 

Marshall

[FSQA]

I agree with Marshall in the above post, you should push for Indicator testing only (if they are not testing for Listeria in their finished product).

 

Otherwise, your testing sequence/strategy looks fine.

Edited by FSQA, 06 November 2018 - 10:13 PM.

[Charles.C]

Hello All, 

 

I'm trying to determine the correct testing in regards to Listeria for my product. We chop and repackage ready for market, ready for retail Brand-Name cookies. I understand Listeria testing can be performed to the following Levels, if you will. 

 

We can simply detect at a "suspect" level if the enzyme is similar to Listeria. 

 

We can further confirm the suspect sample and get a Positive or Negative result. 

 

Further more we can ask to further test the positive result to determine species. 

 

Can someone validate my thoughts are correct and provide input as to most common/acceptable/realistic testing for the industry? 

 

 

Thanks in advance for your help.  

 

Enzyme ?? Listeria is a genus of various bacterial species spp ?? Or is this comment somehow related to the specific procedure ?

 

IMEX customer requirements are sadly not always scientifically logical but suppliers may have no choice but to comply. A fact of business.

[moskito]

Hello,

 

what is said before - I agree. But in most cases you can not argue against customer requirements.

If you have to test you have to test for pathogenic Listeria.

We are producing biscuits and we do not test for Listeria (acc. regulation 2073/2005) on regular basis. Nevertheless we have done a program with biscuits having milk product containing, non baked fat based filling., which does not allow any micro growth. All specification of raw materials at risk used are delivered with CoA for e.g. Listeria and are prepared from pasteurized milk.

 

Rgds

moskito

[Gerard H.]

Hello,

 

I agree with the above. Seen the product characteristics, it's not even likely that a Listeria will survive on the cookies.

 

It looks like the situation, in which your customer has Listeria problems. As they can't find the cause, all raw materials are suspect to be the contamination source.

 

At least, by testing, you will have due diligence that the Listeria isn't coming from your cookies.

 

Furthermore, if you have a good contact with your customer, it could be valuable to have a conversation to pass the message very, very, carefully. But in general, it's very hard to convince the customer, as said above.

 

Kind regards,

 

Gerard Heerkens

[CBMQA]

Likewise we have definitely seen a trend for customer requirements for finished product testing of Listeria in RTE bakery products especially biscuits, bars etc. Main reasoning appears to be if there is an introduction of moisture (water) based cleaning in both the production and packaging areas of the plant hence there might be a risk of environmental contamination of the product post bake with Listeria. For cold set bars with no lethal kill step we generally had felt that this would be correct but with products undergoing a thermal treatment such as baking temperatures generally required in the production of biscuits and bars  there would be limited opportunity for the growth of this organism due to the water activity and product composition providing you don't contamination post bake.

 

In the end we have added Listeria to our standard panel of micro testing for finished product but have been debating the environmental swabbing requirements for minimum ten swabs taken during production off the line pre-baking.

[mgourley]

I had a sales guy come in and wanted to sell me on the fantastic belt cleaner for the product conveyors in the post bake areas of our facility. It was this really great recirculating high pressure water system.
I told him "absolutely not, thanks for coming".

 

We do not do Listeria testing on finished product, but we do swab every drain in the post bake areas of our facility.

 

Marshall

 

[Charles.C]

I had a sales guy come in and wanted to sell me on the fantastic belt cleaner for the product conveyors in the post bake areas of our facility. It was this really great recirculating high pressure water system.
I told him "absolutely not, thanks for coming".

 

We do not do Listeria testing on finished product, but we do swab every drain in the post bake areas of our facility.

 

Marshall

 

 

Hi Marshall,

 

I deduce none of yr customers have requested testing for Listeria ?

 

Yet.

[mgourley]

Charles,

 

Correct. This was one of the reasons for FSMA. Instituting proactive controls for possible food safety hazards. I simply cannot fathom a requirement for listeria testing of finished product cookies with a moisture level of around 3%.

 

Marshall

[Charles.C]

Charles,

 

Correct. This was one of the reasons for FSMA. Instituting proactive controls for possible food safety hazards. I simply cannot fathom a requirement for listeria testing of finished product cookies with a moisture level of around 3%.

 

Marshall

 

IMEX some Customers ask for any species they can find mentioned in the Literature which may have potential safety implications Including the kitchen sink. !

 

For example one notable UK customer required a guarantee of raw seafood being free of Listeria,  a naturally occurring marine species/genus.

(The USFDA at one time also regarded L.mono as a zero-tolerant species in raw seafood, but not for long!)

[012117]

Hi, Shuster.

 

Agree with the posts above regarding challenging testing listeria in cookies. I would, however consider (and would like to understand the enzyme) the following scenario since it is required by customer:

 

What is the limit to be used? How many samples to be analyzed?

 

Is the use of "enzyme" correspond (or more sensitive) to the detection limit for L.Mono analysis? A scenario may arise that for example, you have low level of contamination, which turned to be positive on the "enzymatic test." Will you re analyze the same sample? or you take another sample from the same batch? If you have low level contamination, due to non-homogeneous of microbial distribution, the risk of not obtaining of Listeria would be higher on the re-sample. If this happen, what would be the basis of decision? This can be eliminated if the confirmation of L. Mono is based on the colony obtained from "enzymatic test".

 

It might be better to go with the indicator organism then confirm the colony.