Adam,
Although ammonia is amongst the common products of fish spoilage, in
particular for shrimp and elasmobranchs, but for most of other sea finfish
it is actually a compound called TMA or trimethylamine derived from the
reduction of TMAO or trimethylamnine oxide during fish decomposition. And if
the odor threshhold value for ammonia in fish is 110 ppm, for TMA is only
0.6 ppm, therefore it is most often the TMA level that determines if the
product is being considered spoiled or not. Apart from those two pretty
sharp smelling substances, there is also a gamut of others, some of them
being typical to specific species and others to the spoilage stages and
substrates involved. What all of them have in common, it is their extremely
obnoxious sensory properties but not any risk of burning anybody's mouth at
their predominant concentration levels.
Regards,
Andrew Strak
----- Original Message -----
From: "Adam Simpson" <AdamS@ahsl.co.nz>
To: <seafood@ucdavis.edu>
Sent: Tuesday, May 16, 2000 11:24 PM
> Hi List
>
> I have received several complaints relating to a very strong ammonia smell
> associated with fillets from various different types of fish. I believe
> this is an indication of spoilage and have also been made aware it relates
> to the gutting of the fish. Is there any literature or comments out there
> to provide me with further explaination/clarification? Could this smell
> ever reach the stage of causing a physical reaction such a burns to the
> mouth?
>
> Much appreciated
>
> Adam Simpson
> Health Protection Officer
> Public Health, Auckland Healthcare Services
>
>
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