In the EU farmed Atlantic salmon need not be frozen before consumption in
the raw or lightly processed states because surveys have shown that such
salmon are free from nematode parasites. Nematode parasites are transmitted
to the host fish through consumption of parasitised prey fish, and likewise
other species of farmed fish should also be free of nematode parasites, but
only provided they have been fed on processed feeds, as distinct from
unprocessed, raw, feeds or, presumably, previously frozen raw feeds. I would
still be wary of such derogations from the best practice of prior freezing
of fish destined for raw or lightly processed products unless the specific
combination species and cultural practices had been demonstrated to be safe.
I would agree that the texture of fish frozen according to the requirements
to inactivate trematode parasites - holding at -18 or below for 24 hours -
would be little changed compared with the unfrozen counterpart, and any
change would anyway be well within the natural variation in texture of the
species in question. This observation is based on my experience of
attempting to measure the effects of the freeing/thawing cycle alone, as
distinct from the from the effects of storage in the frozen state, on
texture of fish. If the fish is frozen and thawed under good practices -
frozen rapidly and thawed rapidly - any affects of the freeze/thaw cycle is
difficult to detect even by an experience laboratory panel, and only then
when data are pooled over several samples.
Peter Howgate
This archive was generated by hypermail 2b29 : Tue Jul 26 2005 - 07:48:40 PDT