10 replies to this topic

[hello.fizz]

Hi,

 

We have an oil based sauce that has been getting very high TPC and yeast counts. Our company team, the food safety consultant and the microbiologist at the third party lab have been unable to determine the root cause as of yet.

 

Background

• sauce is made up of herb and oil paste, more oil , raw cashews, garlic powder, preservatives (200), acids (300, 330), sugar, salt and powdered flavours.
• product is not heated and is mixed in blender, dispensed through volumetric dispenser and packed in plastic trays with a heat seal plastic film on top. Some MAP gases used (I cannot recall the exact amount as I write this). Volumetric dispenser is not used for other products due to the presence of cashews. Equipment is all washed and sanitised after use. It is not fully automated- each step involves labour.
• high TPC and yeast discovered during routine testing. A large range of pathogenic and spoilage organisms were tested for and everything else came back at 0. Previous routine testing of this product had no issues.
• retention sample sent and had similar elevated results.
• cashews, herb and oil paste and garlic powder sent for testing and all came back at 0 or <100 cfu/g. 
• I swabbed the hardest to clean part of the volumetric dispenser after cleaning and the results were unacceptable for cleaning, but many decimal places away from the final product TPC and yeast. (It will now be bleached after every use) 
• two more production runs have occurred and the final product results for TPC and yeast are still very high. One sample was sent to the lab a week after production and one was sent literally 2 hours after production. 
• Further samples sent this week which were taken before packing (to rule out the trays/gas). Results have not been received yet.

We have never seen results like this before and so I wanted to ask if anyone had experienced something like this before? Or if anyone can see a gap we might be missing? 

 

Thank you!

[Evans X.]

Greetings fizz,

 

You have been thorough with your investigation, but there are a few more things you can check starting with the plastic tray and the film. There are cases mentioned that microbiological problems were attributed to the packaging. Furthermore there are cases that the packaging was ok, but it was very poorly made that it allowed microorganisms to pass through after the product came into contact, due to deterioration (maybe even not suitable for oil-based products?).

You could also check for poor sealing, due to mechanical problem with the packaging machine(?)!

Also swab and check air quality at the packaging machine, maybe it is not being well cleaned and have cross-contamination when the trays are loaded and are open up to the point they are sealed.

You can check general air quality too in the facilities and the quality of the MAP gases you use. Could be a problem with them or their filters etc.

 

I know it's a pain, but your case is interesting!

 

Regards!

Edited by Evans X., 18 October 2022 - 08:34 AM.

[Scampi]

walk me through the cleaning process for the filling machine?   

[Charles.C]

Hi,

 

We have an oil based sauce that has been getting very high TPC and yeast counts. Our company team, the food safety consultant and the microbiologist at the third party lab have been unable to determine the root cause as of yet.

 

Background

• sauce is made up of herb and oil paste, more oil , raw cashews, garlic powder, preservatives (200), acids (300, 330), sugar, salt and powdered flavours.
• product is not heated and is mixed in blender, dispensed through volumetric dispenser and packed in plastic trays with a heat seal plastic film on top. Some MAP gases used (I cannot recall the exact amount as I write this). Volumetric dispenser is not used for other products due to the presence of cashews. Equipment is all washed and sanitised after use. It is not fully automated- each step involves labour.
• high TPC and yeast discovered during routine testing. A large range of pathogenic and spoilage organisms were tested for and everything else came back at 0. Previous routine testing of this product had no issues.
• retention sample sent and had similar elevated results.
• cashews, herb and oil paste and garlic powder sent for testing and all came back at 0 or <100 cfu/g. 
• I swabbed the hardest to clean part of the volumetric dispenser after cleaning and the results were unacceptable for cleaning, but many decimal places away from the final product TPC and yeast. (It will now be bleached after every use) 
• two more production runs have occurred and the final product results for TPC and yeast are still very high. One sample was sent to the lab a week after production and one was sent literally 2 hours after production. 
• Further samples sent this week which were taken before packing (to rule out the trays/gas). Results have not been received yet.

We have never seen results like this before and so I wanted to ask if anyone had experienced something like this before? Or if anyone can see a gap we might be missing? 

 

Thank you!

Hi fizz,

 

^^^^(red) - TBH, need to know the  Product's target  micro. Standard and some actual numbers for typical/unusual Production and Cleaning-Sanitising.

Otherwise it"s difficult to offer meaningful suggestions.

.

[Tony-C]

Hi hello.fizz,

 

Are these high levels consistent throughout the batch? – S/M/E

Why didn’t you test the sugar and powdered flavours?

 

Kind regards,

 

Tony

[hello.fizz]

walk me through the cleaning process for the filling machine?   

 

I am not 100% sure but believe it is dismantled and washed with hot water and detergent. The pipe is soaked in hot water and detergent, rinsed and soaked in bleach. The other parts may also be soaked in bleach after washing. All our equipment is washed in the sink or for large equipment, washed next to the sink, no CIP.

[hello.fizz]

Hi fizz,

 

^^^^(red) - TBH, need to know the  Product's target  micro. Standard and some actual numbers for typical/unusual Production and Cleaning-Sanitising.

Otherwise it"s difficult to offer meaningful suggestions.

.

 

Sorry for not including that info. The TPC swab was ~2000, and final product TPC is 2-20 million. Yeast swab ~500 and final product 7k-10k. I am not in the office to check the target micro, but I know this is well above the number. The highest TPC I have seen previously would have to be about 2000 cfu/g for a final product and we test 2-3 items per month, including environmental, equipment, water, ingredients, product end of shelf life and product start of shelf life. Previous swabbing in very difficult to clean areas was <500 cfu/g for yeast/mould. We have had up to 1000 cfu/g yeast in some products but they have a consumer cooking step. his product does not specify a consumer cooking step.

[hello.fizz]

Hi hello.fizz,

 

Are these high levels consistent throughout the batch? – S/M/E

Why didn’t you test the sugar and powdered flavours?

 

Kind regards,

 

Tony

 

We have sent these for testing this week, along with a fresh sample that has not gone through the packing machine. I honestly didn't expect to get elevated results again so didn't test throughout the packing process and as it is over multiple dates/batches, the problem seems to be there regardless of start/middle/end. 

[Charles.C]

Sorry for not including that info. The TPC swab was ~2000, and final product TPC is 2-20 million. Yeast swab ~500 and final product 7k-10k. I am not in the office to check the target micro, but I know this is well above the number. The highest TPC I have seen previously would have to be about 2000 cfu/g for a final product and we test 2-3 items per month, including environmental, equipment, water, ingredients, product end of shelf life and product start of shelf life. Previous swabbing in very difficult to clean areas was <500 cfu/g for yeast/mould. We have had up to 1000 cfu/g yeast in some products but they have a consumer cooking step. his product does not specify a consumer cooking step.

Hi fizz,

 

Thks for data.

 

Yr OP has -

"Previous routine testing of this product had no issues"

So what were the typical TPC, Yeast values then ? eg <1M cfu/g, <100cfu/g

 

I note the final product is not heat-treated but are any of the ingredients previously heat treated ?

Yr post OP had -

"cashews, herb and oil paste and garlic powder sent for testing and all came back at 0 or <100 cfu/g."

Is this TPC or Yeast ? If TPC, unless heat treated or similar, <100 cfu/g looks improbable to me.

 

Do you have any earlier swab data for when the product TPC, Yeast results were better, ie in-spec ?

 

The TPC  range 2-20M is rather staggering and also the absolutes although the yeast values maybe less so (but depending on Target and whether heat treated)

 

A little more clarity needed on data - I assume the unit for (2-20M), (7k-10k) is cfu/gram.

But what is the unit for TPC swab 2000 and Yeast swab 500 ? (needs to be in cfu/cm2 or similar for inferential purposes, Z/swab would be sort of meaningless).

 

Do you ever send (a) reference samples, (b) (anon.) duplicate samples for testing ? (this enables an idea of lab reliability)

 

Sorry all the queries but one needs to know the history and whether the C/S is effective.

[hello.fizz]

Hi fizz,

 

Thks for data.

 

Yr OP has -

"Previous routine testing of this product had no issues"

So what were the typical TPC, Yeast values then ? eg <1M cfu/g, <100cfu/g

 

I note the final product is not heat-treated but are any of the ingredients previously heat treated ?

Yr post OP had -

"cashews, herb and oil paste and garlic powder sent for testing and all came back at 0 or <100 cfu/g."

Is this TPC or Yeast ? If TPC, unless heat treated or similar, <100 cfu/g looks improbable to me.

 

Do you have any earlier swab data for when the product TPC, Yeast results were better, ie in-spec ?

 

The TPC  range 2-20M is rather staggering and also the absolutes although the yeast values maybe less so (but depending on Target and whether heat treated)

 

A little more clarity needed on data - I assume the unit for (2-20M), (7k-10k) is cfu/gram.

But what is the unit for TPC swab 2000 and Yeast swab 500 ? (needs to be in cfu/cm2 or similar for inferential purposes, Z/swab would be sort of meaningless).

 

Do you ever send (a) reference samples, (b) (anon.) duplicate samples for testing ? (this enables an idea of lab reliability)

 

Sorry all the queries but one needs to know the history and whether the C/S is effective.

 

Hi Charles, 

The previous tests had 500-900 cfu/g of yeast and same for TPC. We don't have lots of previous testing as the testing was much more scattered (and filed poorly) before I started just over a year ago..

 

I am unsure if the ingredients are heat treated off the top of my head. These results are for yeast and TPC. the garlic is powder, the paste is oil/basil and preservatives and the cashews are not heat treated after shell removal (heat required to remove the shell I have learnt- I posted about these in a different topic as I learnt the spec for TPC is huge as it is not heat treated, but our results were <500 cfu/g for yeast and TPC).

 

We have swab data from other (mostly non food contact) surfaces and never detected yeast. We did have a few TPC detections of about 15 cfu/g (going from memory). I have focused the TPC and Y&M swabs on environmental surfaces over food contact and have used the protein swabs and listeria for food contact surfaces, so the data is not comparing the same type of surface. 

 

Yes, all units are cfu/g. Sorry for not noting that. This includes swabs. I swabbed as close to 100cm2 as I could. 

 

I have spoken to the lab and they did acknowledge they could get incorrect results, but she assured me all their control samples have come out correct. Also, as it has occurred over multiple batches our team feels even if the lab messed up one, it is unlikely they would mess them all up. 

 

I hope this is helpful and I really appreciate your thoughts/advice. 

[Charles.C]

Hi Charles, 

The previous tests had 500-900 cfu/g of yeast and same for TPC. We don't have lots of previous testing as the testing was much more scattered (and filed poorly) before I started just over a year ago..

 

I am unsure if the ingredients are heat treated off the top of my head. These results are for yeast and TPC. the garlic is powder, the paste is oil/basil and preservatives and the cashews are not heat treated after shell removal (heat required to remove the shell I have learnt- I posted about these in a different topic as I learnt the spec for TPC is huge as it is not heat treated, but our results were <500 cfu/g for yeast and TPC).

 

We have swab data from other (mostly non food contact) surfaces and never detected yeast. We did have a few TPC detections of about 15 cfu/g (going from memory). I have focused the TPC and Y&M swabs on environmental surfaces over food contact and have used the protein swabs and listeria for food contact surfaces, so the data is not comparing the same type of surface. 

 

Yes, all units are cfu/g. Sorry for not noting that. This includes swabs. I swabbed as close to 100cm2 as I could. 

 

I have spoken to the lab and they did acknowledge they could get incorrect results, but she assured me all their control samples have come out correct. Also, as it has occurred over multiple batches our team feels even if the lab messed up one, it is unlikely they would mess them all up. 

 

I hope this is helpful and I really appreciate your thoughts/advice. 

Hi fizz,

 

Seems nobody has asked if the finished Product is classified as RTE ?.  (Seemingly, [hopefully], not ?)

 

Re^^^(blue x 2) - this is unlikely to be the correct unit. Need some care in using swab results from an external Lab since many of them  quotie a result equivalent to "1 Swab" (semi-unavoidable if the area is unknown to Lab). (Significantly "overestimates" of course).

 

Personally in such situations my usual approach is (briefly) something like -

 

(1) Locate the Micro Standards for Ingredients/Finished Product and examine for "Realism" based (preferably) on one's own analyses. Critical if RTE.

(2) Similarly for Environmental FCS. ( I would hope that Yeast  is undetectable/Very Low). (I don't understand why you avoid TPC testing fcs after cleaning/sanitising ?).

(3) Compare micro results on finished product to ingredients and Standard.

 

(4) If (1) hopelessly OOS (Out of Standard) > likely problem.

(5) Similarly for (2)

 

(6) If (1,2) OK but (3) mismatched (eg 3 >>1,2) I suggest initially looking for any temperature/time lack of controls in Process.

 

JFI Previous data where Y&M = TPC seems a bit odd to me although may obviously relate to product. . How many days do lab incubate for yeast (see lab report) ?