9 replies to this topic

[Beveragequestions44]

Hi there. We manufacture margarita mixes and after manufacturing runs we send product to a local lab for testing. We have always received results of 0 CFU/mL for Bacteria, Yeasts, and Molds when we test out products due to the process. Our last batch was the first time a colony count was found, it’s was 0.1 CFU/mL of mold. The HACCP plan we have sets the upper limit for mold at 10 CFU/mL as per the advise of the HACCP consultant that we hired, and the FDA regulations. We are looking at testing more bottles to see if this is present in more of the batch and confirm the contamination levels. My question is, at the level of 0.1 CFU/mL, will the batch need to be discarded? How worried do we need to be about contamination at these levels? Is mold growth over the 12 month shelf life possible from starting at these levels? In practice how do large juice/beverage manufacturers handle results like this? Some additional product information: The pH is 3.05 The process is hot fill and hold at a temperature of 190 F There is 500 ppm Potassium Sorbate added Degrees Brix is 18 Thanks for any information!

[Charles.C]

Hi there

We manufacture margarita mixes and after manufacturing runs we send product to a local lab for testing. We have always received results of 0 CFU/mL for Bacteria, Yeasts, and Molds when we test out products due to the process.

Our last batch was the first time a colony count was found, it’s was 0.1 CFU/mL of mold.

The HACCP plan we have sets the upper limit for mold at 10 CFU/mL as per the advise of the HACCP consultant that we hired, and the FDA regulations.

We are looking at testing more bottles to see if this is present in more of the batch and confirm the contamination levels.

My question is, at the level of 0.1 CFU/mL, will the batch need to be discarded? How worried do we need to be about contamination at these levels? Is mold growth over the 12 month shelf life possible from starting at these levels? In practice how do large juice/beverage manufacturers handle results like this?

Some additional product information:

The pH is 3.05
The process is hot fill and hold at a temperature of 190 F
There is 500 ppm Potassium Sorbate added
Degrees Brix is 18

Thanks for any information!

 

Hi BQ,

 

I have 2 queries -

 

(1) afaik, 0.1 is < 10 so result is acceptable ?

 

(2) Assuming that mould is measured by plating 1ml of liquid, how can you achieve a result of 0.1cfu/ml ?

[Beveragequestions44]

Hi BQ,

I have 2 queries -

(1) afaik, 0.1 is < 10 so result is acceptable ?

(2) Assuming that mould is measured by plating 1ml of liquid, how can you achieve a result of 0.1cfu/ml ?

Hi Charles,

I believe 100mL was plated, 1 mL/plate, 10 produced 1 colony, and 90 produced nothing.

I know that the result falls in the acceptable range, but am still concerned about outgrowth in the long term as we haven’t had a result like this in the past

[Charles.C]

Hi Charles,

I believe 100mL was plated, 1 mL/plate, 10 produced 1 colony, and 90 produced nothing.

I know that the result falls in the acceptable range, but am still concerned about outgrowth in the long term as we haven’t had a result like this in the past

 

Hi BQ,

 

^^^(red)

 

IMEX no commercial micro lab could routinely do this level of pour plate repeats since they would likely go bankrupt.

 

It is possible that the "0.1" is "some kind" of an average,

 

I suggest you request more information regarding the specific procedure and method of calculation.

 

It is also conceivable that some contamination might have occurred.

[Beveragequestions44]

Hi BQ,

^^^(red)


IMEX no commercial micro lab could routinely do this level of pour plate repeats since they would likely go bankrupt.



It is possible that the "0.1" is "some kind" of an average,


I suggest you request more information regarding the specific procedure and method of calculation.


It is also conceivable that some contamination might have occurred.

Hi Charles,

Makes sense, I’ll reach out to confirm the exact number plated.

Do you mean that it may be possible that a small amount of contamination happened in the lab or during the plating process?

Thanks

[Charles.C]

Hi Charles,

Makes sense, I’ll reach out to confirm the exact number plated.

Do you mean that it may be possible that a small amount of contamination happened in the lab or during the plating process?

Thanks

 

Hi BQ,

 

^^^(red)

 

I am not directly familiar this measurement (or working with beverages) but IMEX counting methods are difficult to interpret at these low levels (this is why MPN methods are used for items like generic E.coli). As I understand this is also a lengthy incubation.

(IIRC iso offer some specific formulae for "analysing" low counts like this but normally the level is of limited interest compared to Standard so not used very much)

Hopefully the lab did a negative control  to eliminate possibility of (lab) contamination.

 

PS - it is possible the lab used a membrane filtration technique which could enable larger volumes.

Edited by Charles.C, 23 August 2021 - 04:08 AM.
added PS

[Charles.C]

Hi BQ,

 

^^^(red)

 

I am not directly familiar this measurement (or working with beverages) but IMEX counting methods are difficult to interpret at these low levels (this is why MPN methods are used for items like generic E.coli). As I understand this is also a lengthy incubation.

(IIRC iso offer some specific formulae for "analysing" low counts like this but normally the level is of limited interest compared to Standard so not used very much)

Hopefully the lab did a negative control  to eliminate possibility of (lab) contamination.

 

PS - it is possible the lab used a membrane filtration technique which could enable larger volumes.

 

Hi BQ,

 

addendum, here is an example of MF procedure for evaluation Y&M in ice cubes (thawed sample size 100ml, measurements in duplicate )

 

 yeasts and moulds in ice cubes and their survival in various drinks.pdf   147.4KB   31 downloads

 

Y&M Specs for "beverages" seem to vary substantially. I enclose some examples below.

 

 micro. specs beverages.pdf   78.25KB   65 downloads

 

Offhand (not my area) yr result seems rather "unremarkable" to me (assuming mould not toxic) but clearly depends on growth potential within 12 month shelf-life. Do you have any shelf-life validation runs/data ?

 

Hopefully any "drinks" person(s) here can elaborate further.

[Scampi]

I would doubt that a general mold spore could multiply given your product and process

 

And as Charles has pointed out, that appears to be a red herring and not an actual result. OR the lab put the decimal in the wrong place

 

Your product is an acidified food, the pH should negate the high Brix value

 

does it contain alcohol or is it just the mix?

[pHruit]

I've worked with a lot of beverages and seen a lot of results. Some types of result now scare me, as I've seen the end result of what they can mean, and the novelty of mouldy/exploding drinks products really does wear off very quickly...

Thankfully I don't think you're in such a position, and I wouldn't expect to need to discard the batch based on the limited information we have here.

 

False low-level positives aren't unheard of for very low count figures in this type of product, but even assuming that the result is correct and there is a very small amount of viable mould in the product, the preservative should be able to deal with it. I presume you're actually using the sorbate to help with the shelf life after opening? Bars / foodservice outlets can be a bit patchy on storage/stock rotation for this type of thing. The sorbate level you've got in there is more than the legal limit for a ready-to-drink product here in Europe, so it should be more than enough to deal with such a low count!

 

It's worth bearing in mind that your process is very much pasteurisation rather than sterilisation - you should readily achieve a safe product in terms of viable pathogen survival (or lack thereof), but there are things that you may find in beverages that would survive 190°F for a typical hold time, so you may occasionally see non-zero counts.

[Ryan M.]

Even if there was low level mold the potassium sorbate will prevent outgrowth.  It should be fine.