The ideal storage temperature for seafood is 20
degrees below zero. Even if the temperature fluctuates between 20
below and zero there will still be damage done to the product. This
slight flexing of the cell wall will make the fillet mushy. Most
of the damage is done during shipping or if the product is located near
a freezer door that is frequently opened and closed, allowing the
temperature to go up and down. Signs of temperature fluctuations
are ice crystals, distorted shape, clumping and
discoloration.
Fish fillets are 70-80% water, which makes them a
very delicate product to handle. To be properly frozen, the
temperature must drop from 39 degrees to zero almost instantly to
keep the water from expanding. If it expands, the cells are
damaged, and the fillet becomes "mushy." If the product was
properly frozen and it is still mushy, the problem is most likely
in storage temperatures. If the temperature fluctuates
from -20 to zero degrees, even this will cause a slight "flexing"
of the cells and will cause damage. The ideal storage
temperature is a consistent -20 degrees.
Mushy
Fillets