Validated Kill Step for Cereal
Hello! I recently started working for a company that produces RTE cereal crisps (similar to Rice Krispies). We do not have a validated kill step but I have a customer requesting one. Our process is fairly simple, dry powders are mixed with a small amount of water, extruded, cut, and dried in an oven/toaster. Our product is below 5.5% moisture and aW of 0.40. We do not have an in-house water activity meter, only a moisture meter. I have sent out a few samples to prove the correlation between moisture and aW for my own peace of mind. I have a few questions:
- Where would I find information on how many samples I would need to test to prove that X% moisture is equal to X aW?
- Does validation require a Process Authority or certifying body?
- Once I establish the correlation between moisture and water activity, I would send out finished product monthly to continue to verify, would this be sufficient?
Thank you in advance for your help!
Hello! I recently started working for a company that produces RTE cereal crisps (similar to Rice Krispies). We do not have a validated kill step but I have a customer requesting one. Our process is fairly simple, dry powders are mixed with a small amount of water, extruded, cut, and dried in an oven/toaster. Our product is below 5.5% moisture and aW of 0.40. We do not have an in-house water activity meter, only a moisture meter. I have sent out a few samples to prove the correlation between moisture and aW for my own peace of mind. I have a few questions:
- Where would I find information on how many samples I would need to test to prove that X% moisture is equal to X aW?
- Does validation require a Process Authority or certifying body?
- Once I establish the correlation between moisture and water activity, I would send out finished product monthly to continue to verify, would this be sufficient?
Thank you in advance for your help!
There may be some confusion.
afaik a "kill" step typically relates to reduction of a target microbial species ?
I was in a cereal company in MN that did mixing, a small amount of water and then extrusion, over to the oven/toaster and done.
There was no KILL step involved.
If I may, I would suggest going back to the company and asking what KILL step they are speaking off.
Sometimes (ok, a lot of times) customers get stuck on what they hear or certain key words etc and all of a sudden they want everybody to lockstep - sometimes good, many times bad - I think this may be one of those BADs.
Just ask them.
Hi,
As they ask for a kill step validation, you will need to know what is your micro of concern (what you want to kill), worst case initial micro loading and what is your safe final product micro as you will want your validation to prove that you are able to achieve X log reduction of that bacterium (e.g. b.cereus?). You'll need to know heat resistance of your targeted micro. Then, I would measure time / temperature in the oven (or whichever step you decide to be a kill step) if this is possible, depending on the size of your product potentially internal temperate (?) - you could potential make up something bigger than the actual piece of your cereal which could also work as another worst case scenario to prove that even larger than std will get required heat treatment. Knowing time/temp parameters of your process and resistance of mentioned micro you will be able to calculate what level of Kill / reduction you are able to achieve.
On the other hand.. this should come down to your HACCP analysis. I assume your oven roasting is not a CCP? If it isn't, are you able to justify why not - no micro risk? If it is a CCP then in fact should have been validated and see the above ;)
Hope that makes sense
thanks
DM
I agree with Charles that there seems to be a conflation of controls here - your aw is almost certainly primarily about stability rather than a kill step?
It might be the case that the toaster oven process achieves a specific log reduction of a target organism such that it could be validated, but I definitely think Glenn's suggestion is the way to proceed initially, and indeed I've encountered many similar cases of people asking for something because it's on a list of things to ask for, rather than stopping to actually think about whether it's sensible/necessary ;)