Treating seafood with chemicals is intended to help retain moisture before freezing. It is an old practice that has become a standard industry practice.
The idea is that chemical treatment is supposed to help frozen seafood retain its moisture and improve appearance. To do this, seafood is soaked in a chemical additive solution during processing. The most common additive used is a chemical called sodium tripolyphosphate (STPP), commonly denoted as E number E451. The longer the fish soaks, the more chemical and water will be absorbed into its flesh. If the fish is of adequate quality and freshness, then light chemical treatment probably won’t effect things very much one way or the other. However, fish can also be over-treated in this manner.
Over-treating can compromise the integrity of the seafood by causing it to absorb more water than is necessary. This increases the weight and the price, while decreasing the flavor and texture. It is almost impossible to tell if a fillet has been over-treated until it’s cooked. Only when cooked will an over-soaked fish shed the excess water, causing the portion to shrink. The texture of the fillet turns mushy and it will often fall apart. The excess water appears as a whitish liquid that will blow off any coating, cause havoc with deep friers, and dilute any sauce it is prepared in.
We believe that when producers use fresh, premium ingredients like those Vinh Foods uses, then this treatment is optional but not necessary. This is why we only offer our premium fillets either lightly-treated or non-treated. It’s the best way to ensure Vinh Foods’ customers get the greatest value with firm, flaky, and flavorful fillets.