Why Would APC Count Be Higher in Newer Products? Shelf-Life Spec Clarification

Hi everyone,

Can anyone explain to me why an APC count would be higher on a finished product that was manufactured long after the same product that was manufacturing many, many months before? Same storage conditions, etc. 

Also, can I get verification that my specs for APC from the FDA should be between 25-250, or <10. I'm a little confused by the 25-250 range.

Thanks! 

It could be any number of reasons.

APC measures aerobic bacteria.

Is your product stored in an anaerobic package? Like a vacuum bag or a gas-flushed package?

If it is, it would make sense that your older product shows lower APC.
The reduced oxygen would kill off the aerobic bacteria since they need oxygen to survive.

If your "new" product was packaged today, opened, and sampled, it's possible there was not enough time (inside the package) to kill off the aerobic and facultative bacteria.

As for the FDA, it depends on your product, process, and many other things.

Can you link the FDA document you got the 25-250 range from?

It could be any number of reasons.

 

APC measures aerobic bacteria.

Is your product stored in an anaerobic package? Like a vacuum bag or a gas-flushed package?

If it is, it would make sense that your older product shows lower APC.
The reduced oxygen would kill off the aerobic bacteria since they need oxygen to survive.

 

If your "new" product was packaged today, opened, and sampled, it's possible there was not enough time (inside the package) to kill off the aerobic and facultative bacteria.

 

As for the FDA, it depends on your product, process, and many other things.

Can you link the FDA document you got the 25-250 range from?

Hi,

Thanks for your response!

The product is not flushed but is packaged in a sealed plastic (we're talking about individual chocolate covered fortune cookies). These are the specs that I'm confused about:

Batch info                                                                              Testing Date    Shelf life at date of testing   APC (cfu/g)                                                             

If you go down to Section © Guidelines for calculating and reporting APCs in uncommon cases

They mention the 25-250 range because plates within that range are considered usable.

If the count is above 250 on a single plate, the colonies are too crowded to count and may prevent others from growing.

You would need a dilution factor until you get plates within the 25-250 range.

You would then create an estimated value (of total APC) as outlined in that guide.

For your product, I don't know what the acceptable range would be. 

Hopefully someone in the chocolate or baked goods industry can provide some help.

I have APC levels as follows for commercially baked goods and confections with a aW of <0.70.  

<100 cfu/g Acceptable

>100-500 cfu/g Marginally Acceptable (meaning I would then be looking into what is causing the higher APC in the process)

>500 cfu/g Unacceptable (There is a breakdown somewhere in sanitation or the formulation)

My results are generally <50 cfu/g in a chocolate item with minimal additions, and <100 cfu/g with a baked component.  In a prior tortilla and wraps plant <1000 cfu/g was a general result as the aW was >0.91.  So really depends on the formulation and components added, as well as aW, and moisture content.  

You're concerned at results of 40 compared with older results at <10?  Is that correct?  I'd say the differences between those two values are negligible.  Remember that even without the potential that bacteria can die off as mentioned above, microbiological contamination is not necessarily evenly distributed within a sample and in fact, would normally not be.  That's not a result of 1500 then <10 which would be more confusing.