Peter Howgate is right. It certainly sounds like Geosmin and
2-Methylisoborneol which are mouldy earthy flavours that are commonly found
in farmed freshwater fish.
Purging prior to harvest is the only practice to remove the flaour. There is
some anecdotal evidence that purging in slightly salty water also helps.
Alan Snow
Alan Snow Konsulting
44 Marie Street
MURARRIE Qld 4172 Australia
Check out my new redeveloped web site at http://www.askonsulting.com.au/
Phone 07 0418 199 516
07 3390 6220
e-mail ask@askonsulting.com.au
web www.askonsulting.com.au
skype alansnow
-----Original Message-----
From: owner-seafood@ucdavis.edu [mailto:owner-seafood@ucdavis.edu] On Behalf
Of P Howgate
Sent: Monday, 11 December 2006 9:26 PM
To: export@tilapiathai.com; seafood@ucdavis.edu
Subject: Re: off flavor problem
Dear Angus
I assume from your address that you are referring to the muddy flavour that
occurs in farmed freshwater fish. It is not possible to remove it by post
harvest processing. Prolonged washing will ultimately remove it, but with
considerable trouble and detriment to the eating quality of the product.
Masking the flavour by smoking or flavourous additives is not successful
unless the flavour is only very mild. The off flavour is picked up from the
water in which the fish is raised and the only process that has been shown
to be successful in practice is to purge the flavour from the fish by
transferring them to clean water for a few days before harvesting. The
purging time depends on the size of fish and the temperature of the water,
but I would think somewhere in the range of two to six days would be
required. The big problem is how to get clean water without any of the muddy
flavour. It is unlikely that surface water would be pure enough and you
would have to use an artesian source.
Peter Howgate
----- Original Message -----
From: "Angus MacNiven" <export@tilapiathai.com>
To: <seafood@ucdavis.edu>
Sent: Monday, December 11, 2006 9:35 AM
Subject: off flavor problem
> Hi,
>
>
>
> I am looking for any information on the removal of off-flavor
> (off-flavour)
> in processing or pre-processing mainly of fish but information from any
> other aquatic products might be useful.
>
>
>
> Thanks for your time, regards
>
>
>
> Angus MacNiven
>
>
>
> Nam Sai Farms Co. Ltd - www.tilapiathai.com
>
>
>
>
> --
> No virus found in this outgoing message.
> Checked by AVG Free Edition.
> Version: 7.1.409 / Virus Database: 268.15.15/581 - Release Date:
> 09/12/2006
>
>
This archive was generated by hypermail 2b29 : Mon Dec 11 2006 - 13:25:23 PST