Deep Frying Oil | Vector to Allergen Cross Contamination?
Hello to all members,
Our company produces deep frozen: ready to eat meals, savouries and desserts. In the big roll of products we produce pre-fried savouries but we only have one industrial deep fryer. As we produce pre-fried products with fish, crusteceans and meat, my question is: do I have cross a contamination issue during the frying process?... I´ve read some literature and mostly say that cross contamination is a reality, same don´t…Same say "oil may contain allergens of older products"...
I´ve made laboratory analysis to the frying oil for search of Fish with Real Time PCR but the laboratory couldn’t extract DNA because they said oil is an hard sample to extract DNA (I made analysis to oil because it is the main “vector” of cross-contamination). They suggested to analyse a product, so I send to analysis one meat product fried after a fish production and the result was negative for fish detection (Real Time PCR with detection limit of 0,1%).
As we talk about protein, is it possible that high temperatures we run during frying process (175-180ºC) can cause the protein denaturation?... If this happens, are we talking about “false negatives” because the allergen still there? Can I run other type of analysis to get reliable results?
Please help because i'm going crazy with literature with "may contain".... "Avoid"... The allergens stay in oil oil, or not?
Thank you in advance for your precious time and hope to hear from you soon.
Regards,
João
P.S. If you have reliable literature please attch.
Most retailers in the UK prefer you to use ELISA rather than PCR. I would say if I were you I'd set up an experiment and do something which is "worst case scenario". I'd then test the original product for the allergen (to check it's detectable in the first place) and then the oil. The other thing to check is whether you are filtering the oil between uses. If you're not, then the risk is still there IMO from particulates from previous product fried in the oil rather than protein. Don't forget the "yuck factor" as well as although meat is not an allergen, many people exclude it for ethical or religious reasons but still eat fish. Some crustaceans are also prohibited in some religious dietary laws so it's worth considering these factors too.
As for whether it can survive the heat? I'm not sure. Logically your point makes sense, however, I'm not sure I'd want to rely on it. I have read baking processes often don't achieve the temperatures required for sufficient protein denaturation but frying is much more aggressive. Gut feel is you're probably right but difficult to prove.
I would be interested in knowing the results of these tests. I'm severely allergic to fish/seafood (not determined exactly which elements yet) and even have to find vegetarian/vegan wine and beer as the isinglass residue is enough to set me off. It's really annoying as it's happened this year and I've spent 60 years enjoying all sorts of food I can no longer eat!
I haven't seen a risk assessment for protein denaturation for allergens that allowed "allergen removal" in that way. It might exist but my suspicion is that the numbers are really high (to the point of making charcoal/ash). I assume temperatures low enough to not burn your oil would likewise permit allergen proteins to remain intact.
I agree with GMO that the risk will probably be low, but it's not something you can test your way out of. You need some kind of systemic tool to say that all particulates from previous runs have been removed, for that I would recommend some kind of filtration setup for your oil, and verify the process with periodic eliza testing.
As always, don't test anything without an action plan for "unpleasant" results. You can't unlearn information. :)
I´ve seen by your comments that filtration is a key point. Our industrial deep fryer have scrapers running with the conveyor for particules removal and the filtration is running / working constantly. At the end of day the filters are removed and cleaned.
Thank you for your comments.
As always, don't test anything without an action plan for "unpleasant" results. You can't unlearn information. :)
That's a really good point.