Some developing countrys' problem regarding fish preservation is employing formaldehyde to prolong the freshness of fish during catching. A high amount of formaldehyde is found in fresh fish sold in market. I'm curious how to cut the methylene bridge formed by formaldehyde in fish. Anybody have a paper or explanation?
Thank you
When there are adjacent -OH group connected to a molecule & H- connected to a molecule , formaldehyde H2C=O comes to join them by a condensation reaction which eliminates water molecule each time the 2 molecules react:
R-OH + H-R' ---H2C=O----> R-CH2-R' + H2O with methylene -CH2- acting as a bridge or "adhering" the molecules together. You know that phenol-formaldehyde resin is a good adhesive for sandwich wood.
The above reaction is unusual ; it can be catalyzed by acid or by base (the 2 opposites). The connecting bridges increase as long as formaldehyde is present & this leads to a tough thermoset product similar to the one used in cooking utensils' handles "the usually black in color". Breaking them is not easy but these materials can undergo thermal degradation at high temperature forming different "fragmented" products.
I think formaldehyde ought to be replaced by another preservative.
I agree with the Nizar's conclusion.
IARC Monographs Vol 88, regarding formaldehyde:
5.5 Evaluation
There is sufficient evidence in humans for the carcinogenicity of formaldehyde.
There is sufficient evidence in experimental animals for the carcinogenicity of
formaldehyde.
Overall evaluation
Formaldehyde is carcinogenic to humans (Group 1).
I also agree with your conclusion, but in the other hand, we facing problem in the fish market they employ formaldehyde could you give any suggestion to break the bridge in lab or processing method?
Thanks Heru. Just to understand the scenario: is there a maximum use level permitted of formaldehyde as fish preservative?
Yup, actually for fish preservative it restricted in our country, we considering that the fisherman sometime facing problem to preserve the fish so they employ formaldehyde but we are trying to make some method to overcome formaldehyde that already produce methylene bridge in fish body, is it still possible?
I am not aware of methods to break those bridges, however the first question is the health of the fishermen and the consumers.
off course their health is our priority, so when we discuss about formaldehyde, it will affect their live and health, indeed. that's why we are trying to overcome the problem of usage formaldehyde in fish. and also, we trying to reduce the content of formaldehyde in fish sold in the market
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