The lower the storage temperature the slower the speed of chemical reactions
and that may have a linear relationship for ordinary compounds (drop in half
over 10C difference) but on the other hand may be exponential for enzymes.
Besides, with the lower temperature we have less unfrozen water in the
product. Moreover, the partial water pressure above the product is also
going down therefore slowing down the speed of ice sublimation and
consequently product dehydration. That in turn leaves a much smaller
exchange surface for oxygen penetration into the product and consequent slow
down the process of rancidity.
Any PE film is not the best barrier to oxygen also helps with controlling
the surface dehydration therefore, as discussed, while reducing the exchange
area and in that sense helps a bit to mitigate the rancidity issue. But in
order to prevent it, a near total exclusion of oxygen from the product and
its vicinity is require that may be accomplished through application of
barrier type of packaging under tight vacuum conditions.
Andrew Strak
-----Original Message-----
From: Saleh [mailto:saleh_puc@yahoo.com]
Sent: Thursday, July 19, 2001 6:04 PM
To: manimon123@usa.net
Cc: seafood@ucdavis.edu
Subject: Re: Frozen Tuna Loins
I am not sure I got your point. Anyway, that the lower the temperature of
storage it means the slower the speed of sensory quality and it also depends
on your primer plastic packaging. Besides try to keep your product in the
freezer as short as possible, except if you have very low temperature
(minimum -30C) and you may store it for a year. It might be worthful if
using Polyethylene (PE) as primer packaging and store the tuna at very low
temperature.
-----Original Message-----
From: eacharan balachandran <manimon123@usa.net>
To: seafood@ucdavis.edu <seafood@ucdavis.edu>
Date: Thursday, July 19, 2001 3:46 PM
Subject: Frozen Tuna Loins
>
> Dear Members,
> Most welcome for suggestions for prevention of yellow
>discoloration and dehydration in frozen yellowfin tuna loins.
>
> Regards
> Binoy
This archive was generated by hypermail 2b29 : Fri Jul 20 2001 - 09:25:44 PDT