Each hostess at least once in her life prepared such a fish dish for her family. We eat it in a variety of variations. It is dried, smoked, pickled, salted, fried and baked. When buying a fish in a store, you should think not only about how to cook your favorite dish deliciously, but also about how to keep chilled fish in your refrigerator for a long time. Shelf life of it depends on various reasons. Let's find out what is the secret.
What is a fish called chilled?
This is a variety of aquatic inhabitants that are not completely frozen, but only bring their meat to a temperature of no higher than five degrees and not lower than minus one.
At the same time, the fish remains a little longer than if it had not been subjected to cold processing at all. The bacteria responsible for rotting processes do not die, but only slightly slow down their life processes.
The shelf life of chilled fish is approximately two weeks, to be more precise, from ten to twelve days.
How do cooling measures affect fish quality?
Only live fish or which has just fallen asleep are exposed to cooling. The thermal conductivity of each aquatic inhabitant affects how long it can be exposed to cooling, while remaining fresh and suitable for use in food.
The greater the fat content of the carcass, the longer it will take to cool. Also, the speed, conditions and shelf life of chilled fish depend on its size and ambient temperature at the time of implementation of these measures.
During the cooling procedure, an increase in tissue density occurs. Blood becomes viscous, and body weight decreases, since excess moisture evaporates from the surface of the carcass. The greater the humidity around and the less fat the fish, the more weight it will lose.
Greater carcass shrinkage is observed when cooling with ice, and less - when carrying out these measures in a liquid medium.
How is cold treatment carried out?
There are several techniques for cooling fish. The shelf life will depend on which method the suppliers will use.
For this purpose, ice, seawater brought to low temperatures or the same brine are used.
The most commonly used water is in a solid state of aggregation. In simple words - ice. It can be either in the form of large pieces, or finely divided. Manufacturers of fish products use both natural and artificial.
The following types of solid water are distinguished, which is used to increase the shelf life of chilled fish:
- snow ice;
- with the addition of antibiotics (most often biomycin);
- with the use of antiseptics (hydrogen peroxide, sodium hypochlorite and others).
And what manipulations are carried out with the fish?
Before cooling, all the fish are weighed, then placed in containers and filled with prepared ice.
The amount of solid water depends on how far the fish will go before it is put up on store shelves. Of great importance is the time of year of transportation. If the air temperature does not exceed the mark of plus five degrees, then ice is taken in relation to the mass of fish exactly half. The higher the air temperature, the more it is taken. For example, with a thermometer mark above plus five - 60% of the ice, and at a mark of plus ten the mass of ice is equal to the mass of all transported fish.
Regardless of the production of medium or small sizes, it is sprinkled with a cooler from all sides. This helps to increase the shelf life of chilled fish.
Signs that the fish arrived at their destination fresh
Transported products can be chilled either completely or slightly modified. For example, a fish can be completely cleaned from the insides or with gills removed, and it can also be cut into small pieces.
Fresh and well-chilled fish has the following symptoms:
- It does not emit an unpleasant odor.
- Body color is natural.
- The skin is not damaged and clean.
- The eyes are light and convex.
- Gills have shades of pink and red. At the same time, they are covered with transparent mucus.
- The meat is firm or slightly soft to the touch, but not flabby and falling apart.
If the fish is not a sturgeon, then its gills may have a slightly sour smell, which disappears as soon as the aquatic creature is thoroughly washed.
Shelf life of chilled fish in the refrigerator
We should not forget that such products are not stored for long. The fish is in refrigerators at temperatures from zero to minus five degrees. Relative humidity is kept in the region of 98%.
Under such conditions, cod does not lose its qualities for up to twelve days, sprats for up to three days, mackerel for four, herring for one and a half, partial fish are stored for up to eight days.
The shelf life and storage methods of chilled fish in places where there are no cold rooms differ. If the products are delivered to a store where there is no refrigerator, then their sale within eight hours is permissible. At temperatures in containers up to zero degrees, you can sell fish during the day. Storage delays are not allowed if the ice has completely melted.
Under these conditions, aquatic inhabitants are stored in utility rooms at a temperature not exceeding zero degrees, and at the point of sale, such a quantity of products is sold that they are sold within two hours.
Shelf life and features of cooling sturgeon fish
These types of fish are gutted before cooling. A prerequisite is bleeding. To do this, the tail stem or gills are cut in a still living fish.
In fish, viscera, milk, head and all fat deposits are removed. An exception is sterlet. It is not cleansed of internal organs, head, fins and gills.
Storage of cod and carp species
Carp breeds are chilled whole. Exceptions are marinka, Dnieper barbel and Ottomans.
Small cod breeds are also not gutted. But representatives of this species with a mass of more than half a kilogram must be cleaned of the entrails and caviar.
Features of cutting some types of fish
The shelf life of chilled fish and technical conditions depend on the type to which these or other aquatic inhabitants of rivers, seas and oceans belong.
How is gutting carried out?
- During this procedure, perches remain without gills. But they, like fish of cod breeds, leave milk and underdeveloped caviar.
- Haddock, sea bass, rasp, saithe, cod can be left with a swimming bladder and anemia.
- Cod rocks are cleaned from the abdominal cavity along with fins located on the peritoneum. The fish can be cut down from the anus by another two centimeters.
- Sturgeons are completely bled, beheaded and gutted. An exception is sterlet.
- Flatfish fish cut off their heads and remove their internal organs. You can leave milk, caviar and kidneys.
- Salmon can be delivered either completely gutted or whole.
- Large catfish must be gutted, as well as a large pike.
- The body temperature of the carcass should be from minus one to plus five degrees.
The shelf life and quality requirements for the storage conditions of chilled fish undoubtedly affect the freshness of the product. Consider what organoleptic signs it can be said that the fish is fresh or, conversely, that you should refuse to buy such a product.
Benign fish: what does it look like?
The following signs are distinguished by which it can be said that the products sold on sale are fresh:
- Solid fins.
- Closed mouth.
- Gill covers do not leave the gills themselves.
- The abdomen of the fish does not look swollen.
- Sunken anal ring (and at the same time it is light pink in color).
- The skin is bright and clean.
- If the fish is a breed of scaly, then its scales are tightly attached to the carcass.
- The mucus that covers the body must be thick and free from unpleasant odors.
- The eyes are bulging, bright, and the cornea is elastic.
- The meat of aquatic inhabitants is dense with natural color. It does not have an unpleasant odor and when cutting the carcass it is poorly separated from the bones.
- If you click on a fish in the area of the spine, then a pit forms in this place, which immediately disappears.
- The internal organs look natural, not crushed, and without the presence of an anemone.
- If the fish is fresh, then its blood is dark red in color, which will quickly coagulate in the fresh air.
- A benign fish goes to the bottom in a container of water, since its density is more than one.
Spoiled fish, what signs does it have?
- From the deformed body comes a fetid odor.
- The fins are torn off, and the gills are covered with dirty mucus.
- Gill covers extend from the gills, they are raised, and the mouth of the fish is open. If you squeeze the lids, then the sucrose will stand out.
- The abdomen of a carcass can be either swollen or burst.
- The anal ring bulges outward and has a dirty red color.
- The skin is wrinkled, and if it is a scaly fish, then its scales are kept weak and fall off.
- The eyes have a dark, dirty color. They are muddy and buried inside the eye sockets.
- The meat of the carcass has dark shades, it is flabby to the touch and is easily separated from the bones.
- The internal organs are squeezed, have an unnatural color, are covered with unpleasant putrefactive mucus and a sacrum.
- Spoiled fish will not sink in the water.