Trying to assess microbiological risks
Hi everyone,
I have a process with rework and I'm trying to assess microbiological risks.
In general, the overview of the process you can see from the picture enclosed.
About the product. Its major part is potato flakes, on the second place there is potato starch (all the other ingredients form less than 10% from dry blend). Dough humidity is about 30%.
About the process. Dry ingredients blend and mono-glyceride are combined in a dry mixer. This dry mix together with grinded scrap enter the wet mixer, where water is also added. Dough leaves the wet mixer, comes to sheeting and then dough sheet is cut. Semiproduct is conveyed to a fryer, while scrap goes to a grinder. Grinded scrap is then transported back to the wet mixer.
Currently I am concerned about germs proliferation in the wet mixer (cause there water is added) and the grinder (cause there can be dough build-ups). At the same time I don't exactly know which kind of microbes will be the most significant.
Can anyone suggest any other process points to consider and to name germs that can be a concern?
That re-work section scares me the most. The build up constantly recycled waste material will certainly raise micro levels. As you can see a % of re-work could almost constantly be re-worked!!
Yea, your wet mixer and the grinder are the areas I would concentrate on.
Hi everyone,
I have a process with rework and I'm trying to assess microbiological risks.
In general, the overview of the process you can see from the picture enclosed.
About the product. Its major part is potato flakes, on the second place there is potato starch (all the other ingredients form less than 10% from dry blend). Dough humidity is about 30%.
About the process. Dry ingredients blend and mono-glyceride are combined in a dry mixer. This dry mix together with grinded scrap enter the wet mixer, where water is also added. Dough leaves the wet mixer, comes to sheeting and then dough sheet is cut. Semiproduct is conveyed to a fryer, while scrap goes to a grinder. Grinded scrap is then transported back to the wet mixer.
Currently I am concerned about germs proliferation in the wet mixer (cause there water is added) and the grinder (cause there can be dough build-ups). At the same time I don't exactly know which kind of microbes will be the most significant.
Can anyone suggest any other process points to consider and to name germs that can be a concern?
Hi Constantine,
I would personally look hard at the wet mixer, grinder, sheeting, and cutter operations. All of those areas would have rework coming back through, and the way it appears, all of those areas would contain some form of moisture. You should be less concerned (not saying totally unconcerned) with the fryer and the dry mixer, since the fryer is likely to kill off quite a bit of micro, and the dry mixer shouldn't be introducing any moisture. The wet mixer and grinder probably would have the highest micro content, but the micro you get from those areas will be passed along to the sheeting and cutting areas.
As JohnWheat mentioned about the constant rework, do you have some sort of gate system that only allows a certain weight of rework from the grinder to enter the wet mixer during each batch?
QAGB
Thanks guys!
Well, when the line gets aligned and rework is returned to the wet mixer, it is expected that rework will form about 50% of the dough in the wet mixer (so there will be 50% of fresh ingredients and 50% of rework). So you're all right - it may appear that some rework can recirculate for many many times...
I must also specify that the wet mixer is going to be constantly cooled down to 7 C. The grinder won't be cooled, though there are not many possibilities for build-ups.
About sheeting and cutter - I haven't seen any build-ups here, but I'll double check them :smile:
Does anyone have any ideas about the particular germs I need be concerned about?
Thanks guys!
Well, when the line gets aligned and rework is returned to the wet mixer, it is expected that rework will form about 50% of the dough in the wet mixer (so there will be 50% of fresh ingredients and 50% of rework). So you're all right - it may appear that some rework can recirculate for many many times...
I must also specify that the wet mixer is going to be constantly cooled down to 7 C. The grinder won't be cooled, though there are not many possibilities for build-ups.
About sheeting and cutter - I haven't seen any build-ups here, but I'll double check them :smile:
Does anyone have any ideas about the particular germs I need be concerned about?
Hi Constantine,
That's a very high rework percentage. However, if no one has questioned you on it, I won't either. It's good that you are cooling your product, but 7oC is still in what is called "the danger zone" for microbial growth in food. You should ideally be less than 5oC to be outside of the danger zone. Also, you might not visibly see buildups in your sheeting and cutting operations, but biofilms you cannot see can build up and cause micro issues.
Raw potatoes have risk of the numerous pathogens that live in soil: several types of Clostridium, Listeria monocytogenes, Campylobacter, Bacillus cereus, etc. I would assume your potato flakes and potato starch are both being handled (prior to receipt) for pathogen reduction/elimination, so the risk would be less in that case. However, there is still some risk involved since you are rehydrating the product.
QAGB
Ok, thank you!
not related to your question.. but could help someone out there