Should I continue micro testing for E. Coli, Salmonella, and Listeria Species on a product with a PH under 4?
There are no customer requirements to perform the testing. We have done the testing so far as a means of verifying the quality. PH was 3.7 when tested recently.
Thanks in advance for any ideas, help, or advice.
Might be useful if you can provide a bit more detail about the product and process to which your query relates, as it is difficult to give any sort of informed advice otherwise!
Some of these certainly could be an issue in some products at pH<4 in some circumstances - e.g. cases of Salmonella, E. coli and Cryptosporidium linked to unpasteurised fruit juices.
The bacteria you mentioned may "survive" in that pH and not really "grow". If you are pasteurizing, them then they will be destroyed with the exception of spore forming bacteria like Bacillus and spoilage Lactobacillus. I agree with pHruit, need more detail..
Thank you for the feedback so far.
The product is dehydrated fruit and there is a small amount of water used in the processing. There is no pasteurization. The finished product has citric acid added to it in addition to it already being in the raw ingredient (dehydrated fruit).
Thank you.
The bacteria you mentioned may "survive" in that pH and not really "grow". If you are pasteurizing, them then they will be destroyed with the exception of spore forming bacteria like Bacillus and spoilage Lactobacillus. I agree with pHruit, need more detail..
Thank you for the feedback so far.
The product is dehydrated fruit and there is a small amount of water used in the processing. There is no pasteurization. The finished product has citric acid added to it in addition to it already being in the raw ingredient (dehydrated fruit).
Thank you.
So this is a finished RTE product, with no kill step in the process?
You mention dehydrated fruit, so is aw also a control for the product?
Either way it seems like the primary control is going to be via the raw materials - what is the micro specification for these, how well do you suppliers control this and is it actually achieved routinely, do you have the data to substantiate this etc.
Possibly another significant consideration is the impact of your own process through hygiene status, so how well validated is your cleaning process, how are you verifying it etc.
The other way to look at is perhaps to ask if there is a reason to *not* do some analysis for ongoing verification?
It's not normally overly expensive, so are these e.g. very short shelf life products such that turnaround for micro is a delay that wastes a significant proportion of life?
I wonder if a pathogen challenge study wouldn't be your best option. You could challenge your product with the pathogens you are listing, and then see if the process is good enough to kill (reduce by over 5 logs) those pathogens. If you have data to show that your process eliminates the pathogens, then you don't need to keep testing finished product (as long as the pH and aW are monitored and are the same for each batch, per CCPs). You could contact your lab about this and see if they can do it, or send me a private message and I can also point you in the right direction.