EU regulation no 2074/2005 gave the maximum level of TVB for fish in 3 categories as 25, 30 and 35 mgN/100 g.
I need to know what are the basic to set this level. Is that only organoleptic rejection level or any other parameter involved it?
I agree completely with Peter Howgate words. Perhaps he is the main living expert on TVBN in fish. But it is not a problem of authority and/or expertise. TVBN depends on a number of factors very difficult to handle in practice:
(i) On the methodology utilized (distillation methods yield in general higher values than diffusion methods, but it does not means that distillation methods give similar values).
(ii) Each fish specie has an "initial" TVBN (it is not zero). However, this initial TVBN° could change with the season (spawning influence) and capture method.
(iii) On the type of fish. White lean fish (like cod) and lean flat fish show the lowest TVBN°, fatty fish like sardines and tuna have higher initial values, and elasmobranch like rays and sharks usually have the highest.
(iv) In general each fish specie, during a given season (and for a capture method) has a TVBN dynamics. During a initial phase after capture TVBN° remains more or less constant, but after certain point (depending on the fish specie, but also on storage temperature and fish handling) star to increase exponentially.
(v) In theory regulatory limits provide for an allowance te decide between "spoiled" and "non spoiled" fresh fish (only fresh fish!). After the limits the regulator has assumed that the fish is spoiled and unfit for consumption as such in the EC.
(vi) In the very old literature it was the justification that after certain level of TVBN (say 50 mg) started (even in white lean fish) the production of non-volatile amines (like putrescin and cadaverin) that could be considered toxic. But I have not seen recent confirmation on that; and there is a long discussion about this, because without this justification the limits are based on quality reasons and not on safety reasons.
I do not think this is a type of regulation that will change any soon. TVBN assay it is relatively easy and inexpensive to perform, all fish technologists know about it (at a certain time it was said that you could not consider a fish technologist without publishing a TVBN paper at international level - I did). I think that all serious fish technologists know about the problems with TVBN, but a method to suit regulators in the EU has not been found yet.
My best advice is that you have to search and know about your fish TVBN dynamics and TVBN° to identify conditions and seasons for your fish to be exported to the EU.
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