Is Yeast and Mould good enough for Ambient Air Testing?
Hello everyone! I am currently working on a non-conformance dealing with annual ambient air testing. I have several years of lab work both food safety testing that focused on cheeses and working in two cheese plants. Currently I work in an ice cream factory. We were told our facility was considered high risk and needed to perform ambient air testing.
I know from my previous experience in the independent lab, factories would buy DRBC plates and use them to test for yeast and mold. A plant I worked at tested air quality with PDA agar plates. Another one used petrifilm Y&M and petrifilm APC that we tapped to the walls for 15 minutes and read the plates later. I ordered PDA plates from an outside lab to use for ambient air testing as we don't have Y&M and APC petrifilm at my location.
Speaking to the auditor, I told him of my experience with ambient air testing and how DRBC and PDA were the standard that I had experienced and he suggested that would be a good way to go.
As it stands now, it appears for the non-conformity will require APC testing, however the lab we go through only had PDA plates for this ambient air. Are there any alternatives to testing APC or do you guys think Yeast and Mold is good enough? My past experiences lead me to believe this can be the case, but since I have transitioned from cheese to ice cream, maybe it's a bit different since Y&M isn't as much of a concern for frozen products. Does anyone have suggestions on how to test APC that doesn't require APC petrifilm since this will just be annual.
Thank you for your time!
Greetings Verdy,
Since PDA and DRBC are Y&M specific, there could be problems for APC to grow on them. There is quite a variety though on which you can grow them. Most common and easy to find or make are Plate count agar (PCA), Nutrient agar (NA), Tryptone - soya agar (TSA), Tryptone - soya - yeast extact agar (TSYEA). This means a medium in a plate, there is no need to be a petrifilm.
Also, since your topic is about environmental air testing, Y&M are a concern and you should perform a test once in a while, no matter the product.
Regards!
Hi Verdy, I'm working for ice cream factory too. I'm testing air for Y&M, once a month, using PDA plates. Then, I send plates to the accredited lab for testing. Y&M is quite sufficient, at least CFIA never objected that.
Hi Verdy, I'm working for ice cream factory too. I'm testing air for Y&M, once a month, using PDA plates. Then, I send plates to the accredited lab for testing. Y&M is quite sufficient, at least CFIA never objected that.
Hi Olena,
IMO you have a kind auditor(s).
It seems (to me) microbiologically illogical to monitor the quality of air without measuring APC (or an equivalent characteristic).
After consideration, I am going to be testing aerobic plate count using SMA plates. Looks like our outside lab does carry them!
Now another question: What is a good limit for that? The only plate I tested APC (using petrifilm) had a limit of 100. We do test our product routinely for APC as well and haven't had any issues, so I feel like 100 is a decent limit. In ice cream the limit for APC is 50,000!
Thanks, y'all. :)
After consideration, I am going to be testing aerobic plate count using SMA plates. Looks like our outside lab does carry them!
Now another question: What is a good limit for that? The only plate I tested APC (using petrifilm) had a limit of 100. We do test our product routinely for APC as well and haven't had any issues, so I feel like 100 is a decent limit. In ice cream the limit for APC is 50,000!
Thanks, y'all. :)
100 what ? etc, etc
Ambient air testing is required or mandatory for small industry /cottage industry dealing in cosmetics.
100 what ? etc, etc
For my old plant, it was a count of 100 colonies on the aerobic plates that would signal us to alert maintenance. I was going to use that as my limit here as well, unless others thought it should be less than that. :)
We do Y&M every month. We don't typically have Yeast or Mold problems with the products, but it can happen just given the nature of the industry. I feel that it's more likely to come from the raw materials (vendor) at this stage than the inside of the packaging facility, so we haven't given Y&M testing much though. It's just something our auditors apparently wanted us to do.
So far I haven't seen values exceeding 200 CFU/hr in active areas. Most of the values though are around 40 CFU/hr. Should these be a cause for concern ?