Moisture content in fish

The moisture content of fish is usually expressed on a wet-weight basis – i.e. is the mass of water in a unit mass of the fish.

Water is the principle component (up to 80%) of the edible portions of seafood. Usually the oil and water content together total about 80%.

Depth and altitude of fish catch can influence the moisture content of fish. Fish from deep water and from northern latitudes have higher moisture and lower fat content.

The method of storage as well as further processing, such as freezing determines the final moisture content of the fish flesh. Considerable moisture, as well as soluble nutrients, may be lost in thaw drip. Water retention is highest in fresh fish.

Salmon fish

Finfish moisture contents generally show an inverse relationship to the lipid content. The average percentage of moisture in raw edible flesh, summarized from various sources, is 77.2 with a range of 64.3 – 82.8%.

Raw shellfish moisture contents fall in the same range as finfish, but average is slightly higher, 80.1%. About one fourth of the moisture can be lost during cooking, which results in concentration of other components.

For fish jerky the amount of moisture should be 15 to 20 percent. This low-moisture content is sufficient to inhibit the growth of harmful bacteria without added preservative.

To maintain quality, commercially packaged frozen fishery products should, be placed in the freezer, in their original moisture-vapor-proof wrapper, immediately after purchase. Store in freezer to -18 °C or lower. At the temperature above -18 °C, chemical changes cause the fish to loss color or flavor, texture and nutritive value.
Moisture content in fish