Dear Jiwa
You do not describe the circumstances in which you want to ice your fish -
on board a fishing vessel and what sort, during distribution on land and
what type of vehicle, and such like - to give relevant advice. I suggest you
go to the FAO Fisheries Department site:
http://www.fao.org/fi/struct/fiiu.asp. From there go to publications and
work down to T331, 'Ice in Fisheries', and consult that. However it does not
cover 'ice slurry' systems. The file is in HTM format and you can download
it.
Generally, packing the fish in flake ice in boxes is by far the simplest
method of chilling fin fish and holding it for storage and transport, and it
is very effective. Boxes should have holes to allow melt water to drain away
and the ice should be topped up as its melts. Ice slurry is good for rapid
cooling of fish, but is not all that convenient for storing and transporting
fish. More ice is required to cool the fish than direct cooling with ice as
the water making up the slurry has to be cooled as well as the fish, and
there is extra weight to transport. We need to be careful with terms here. I
am using 'slurry ice' to mean a mixture of crushed or flake ice with a small
amount of water in a container just enough to make the mixture mobile, and
the fish is put into that. The system is intended for cooling fish rapidly,
but not as a means of storage of fish. You should not allow too much melt
water to collect in the container so that there is a layer of water with ice
floating on top. When the fish is cooled the water should be drained off and
the fish stowed in ice. A variant of this is to cool seawater or dilute
brine rapidly so that ice forms as very small crystals. This slurry is
pumpable and because of this has advantages in icing fish in fish rooms. It
is possible you have in mind CSW, Chilled Seawater, which is a mixture of
ice and seawater used on pelagic fishing vessels. Tanks on the vessel are
charged with ice at the port and just before the catch comes aboard seawater
is put into the tanks to forma slurry and the fish is added. The water must
be circulated. This system does not require refrigeration machinery so is
simpler than RSW, refrigerated seawater, which does. Again, RSW is mainly
used on pelagic fishing vessels, and on tuna boats, to effect rapid cooling
of bulk catches. Air chillers are not to be recommended; heat transfer is
much slower than using ice, and the surface of the fish dries out.
Peter Howgate
----- Original Message -----
From: "SALES" <sales@tafish.com>
To: "Seafood research and extension information exchange"
<seafood@ucdavis.edu>
Sent: Saturday, January 06, 2007 5:43 AM
Subject: Re: ice slurry
> Dear All,
> Best Wishes for 2007
> Can any one guide me on methods of chilling sea fish,how to prepare ice
> slurry ,which is best method ,Ice slurry ,RSW
> or refrigerated Air chillers,primary product to chill is fin fish.
> Thanks
> Best Regards
> Jiwa
> Transafrica fisheries
>
>
>
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