Fish preservation by salting method

The purpose of processing and preserving fish is to get fish to an ultimate consumer in good, usable condition. Prompt preservation of fish prevents decay and maintains the quality of the fish.

Different processing and preservation methods like salting, drying, smoking, chilling, freezing, chemical treatments, as well as combination of these two or more methods (referred to as hurdle technology) are used for the preservation of fish.

Salting is one of the oldest techniques for preserving fish, and it is a traditional processing method in many parts of the world. Salting is a simple method of fish preservation, with salt and fish, and sometimes water, as the only ingredients.

Salted fish products have been shown to be safe for consumption. The main purpose of salting is to separate water from the fish and replace it with salt. Thus, the water concentration in fish decreases.

As the water moves out, the salt moves in, penetrating deep into the flesh of the fish. Water is essential for bacteria (germs) to grow, so if the water is removed, bacteria cannot grow.

The salting process can be wet, dry or a combination of the two. Salting followed by open-air sun drying is commonly used by traditional processors because it is cheaper and easily adaptable. Only a few traditional processors use solar drying.

The principle is to keep the fish for a long time in brine. The equipment needed consists of a watertight container, which can be a tin, drum, canoe, barrel, etc. While in dry salting the fish is salted but the juices, slime and brine are allowed to flow away. Dry salting can be done in an old canoe, or on mats, leaves, boxes, etc. In any case, the brine formed by the fish juices and the salt must be allowed to run away.

Salting is a process where the common salt (NaCl), sodium chloride, is used as a preservative that penetrates the tissue; hence slows the bacterial growth and deactivates the enzymes. Salting helps the drying process too, as it binds the water, making it unavailable to bacteria.

Some of the factors involved in salting of fish which play important role are purity of salt, quantify of salt used, method of salting, and weather conditions, flavor of the product.

It is important to use clean, dry salt for preserving fish. Dirty salt should not be used and if the salt is wet, it must first be dried. There are some special bacteria that like to live in salt-- these are called the salt-loving bacteria or halophiles that can spoil fish, producing unpleasant smells.

The flesh of groundfish, such as cod, contains about 80% water. When salt is added to the surface of a fish, some dissolves in this water. If the fish is examined shortly after salting, it will be found that the surface has become quite sticky. This is because the salt affects the protein in the flesh and makes it swell and absorb salt and water.
Fish preservation by salting method

Protein Quality in Seafood

Protein Quality in Seafood
Protein quality is determined by the amount essential amino acids present.

Mostly, but not all, animal protein is a complete protein (all essential amino acids present at required levels).

In contrast, most protein from plant sources lack adequate amounts of one or more essential amino acid and are “incomplete.”

Combining small amounts of high quality animal protein with plant proteins improves the quality of the latter.

The quality of seafood protein is high, comparable with meat and poultry. Amino acid values compare well with the FAO reference pattern.

It high quality protein makes seafood a attractive accompaniment to vegetable protein sources such as legumes and cereal grains where a small amount of seafood will greatly enhance the value of the vegetable protein.

Nutritive quality and protein efficiency ration (PER) ranks fish protein above casein, the major protein in milk.

Protein form seafood us easily digested, with most species showing a protein digestibility greater than 90%.

The protein of minced flesh of underutilized species and by catch is generally comparable in percentage of protein, amino acid profile, chemical score, and protein efficiency ratio to fillet protein.

Surimi and products made from it supply essentially the same nutrients as the minced flesh from which it is made, with several exceptions.

Less niacin and potassium is present, and added salt increases the sodium content.
Protein Quality in Seafood

Methods That Keep Seafood Alive

Methods That Keep Seafood Alive
The trapping techniques certainly provide the best opportunity for the fisherman to land and supply the freshest highest quality product. When an animal becomes trapped in a closed area, it remains alive and untouched until it is removed. Therefore, as long as the traps are judiciously operated and emptied on a reasonably cycle the seafood is removed and slaughtered just prior to sale or use.

An excellent example of the use of traps (pots) is the crab industry. In fact, most crabs must be butchered while alive in order to ensure that the meat is well bled. Otherwise there will be a “blueing” of the meat. This is due to the blood chemistry of a crustacean.

While most animals have a heme (iron) complex in their blood, crustacean have a copper complex. When the blood is not removed prior to processing, the copper oxidizes, giving the giving the white crabmeat an unsightly blue color. Although the basic nutritional value is not impaired, the sensory-oriented consumer does not like and will not purchase blue colored crab.

The ultimate in retaining live fish and shellfish in containers or penned areas is found in fish farming or aquaculture. In this case, the raw materials are raised throughout their life cycle in captivity in a normal farming type operation.
Methods That Keep Seafood Alive

King Crab

King Crab
This species is not a true crab but is similar to crabs in structure and habits. It is much larger than other crabs, attaining a spread of about 5 ft (1.5m) and a weight of about 24lb (10.9kg).

King crabs are caught off central Alaska to the Aleutian Islands and off the islands of northern Japan. They are harvested with large rectangular pots. Aboard boats, the crabs are held in the live state in wells of circulating seawater.

King crab meat is either canned or frozen. In canning, the whole crab is cooked in boiling water, after which the meat is squeezed out between rubber rollers. The meat is then washed, packed in cans in a weak brine, and the cans are sealed, heat processed, cooled and stored. The meat may be frozen in large block for the restaurant trade. The legs and claws are also frozen for retail outlets and restaurant.

It properly packaged and frozen to a temperature of 0 degree F or below and held at this temperature. King crab meat has a high quality storage life of at least 12 months. Lower storage temperatures provide for an even longer storage life.
King Crab