Pseudomonas, Vibrio, Proteus
Figure 3-2. Microbial conditions of waterfoods.
a. Definition. Dehydration is a loss of water from a product, usually due to
improper storage conditions. You, the veterinary food inspection specialist, will examine
the product and determine if a dried or porous surface and a dark color exists. These
are determining factors for this deteriorative condition.
b. Non-Frozen Product. Dehydration of a non-frozen product results in a
drying out (dry, shrunken appearance) of the surface, usually accompanied by a
darkening of the product. This darkening is due to an accumulation of solid matter.
c. Frozen Product. Dehydration (freezer burn) in a frozen product is evidenced
by a porous texture, whereby the tissue becomes tough and fibrous. When this
condition exists, protein denaturation normally occurs. The abnormal color may appear
as patch-like areas. The affected product will retain its original shape.
Watermarking is a physiological change particular to salmon. Two changes may
occur. One is a skin color change (light pink-brown to dark red-brown, depending on
species) coupled with a thickening of the skin. The other change is mottling and color
fading of the flesh. Watermarking that affects skin but does not noticeably affect the
flesh is acceptable. If the flesh is noticeably affected, the product is not acceptable.