High TPC in products

Hi,

We are a newly built company that produces dried algae biomass. We use a spray dryer to dry the slurry into fine powder. The temperature set is 200 degree celcius. The production area and the spray dryer as well as other equipment are cleaned with water and sodium hypochlorite. 70% ethanol is used as disinfectant.

The TPC results are out of specification and keep on increasing. Limit is <1 x10^7. 

 The slurry was tested before each spray dry and the result we found was around 1x 10^4. However, once it is spray dried, the powder contains more than 1 x 10^7 cfu/g. We did swabs the spray dryer parts and the swab results were >10cfu/10cm2. 

I need to decide on the corrective actions and please advice on how to find the source of contamination. I need your help to guide me on this issues ( what should I do? and any solution that can be done to encounter this issue)

I really appreciate your help.

Thanks

Hi,

just brainstorming here  - maybe something conected with cooling air supply. Would need to see process diagramm to give some conclusions. You can contact me on xxx (my bussiness partner just got doctoral degree about spry drying systems - maybe we can help).

BR,

Ivars 

Sorry but I don't understand the system, surely 200degC should give much, much less than 10⁷ cfu/gram ??

Surely will be time / temperature dependant?

What is the temperature of the room your spray dryer is in?  If the room is too cold, product on the outsides of the dryer may not get to the 200 degrees and cause a problem.  What type of spray dryer are you using?  Is there a baghouse?  If so, when was the last time you changed the bags?  Sometimes product can also accumulate there and chunks of old/bad product can contaminate your good product.