Now the supermarket is selling a lot of aquatic products are frozen good, IQF frozen aquatic product the most common is the shrimp and fish, IQF frozen aquatic product before to introduce how to choose fresh aquatic products, IQF frozen aquatic product that method applies to frozen aquatic products? , We specifically look at it!
Buy frozen shrimp, if there is a package, then depends on the packaging is not complete, there is no sign of dissolution; general high-quality shrimp meat into a light blue or milky white, no smell, clean and tidy; poor shrimp tissue loose, Color redness, the body is not clean, IQF frozen aquatic product there are sour smell.
To determine whether the frozen fish is fresh can be identified by fresh fish, but the standard is lower than the fresh fish.
1, frozen fish eyeballs such as raised, black and white clear, clean, no dirt, then it is relatively high quality, if the eye subsidence, there is a layer of white film is not very good.
2, high-quality frozen fish fish solid, IQF frozen aquatic product white without dirt, anal tightening; poor frozen fish fish swollen, body color bleak, anus raised.
3, if cut open fish, internal organs and meat thorns is good quality frozen fish.
Fish body changes include the fish after the death of their own physiological changes and the role of the external environment caused by corruption and deterioration. IQF frozen aquatic product Bacterial corruption is the most serious deterioration, so that the loss of practical value of fish and economic fish from the fresh to the freshness of corruption after the process of change, generally divided into dead posture, IQF frozen aquatic product autolysis and corruption in three stages.
(A) dead after the death of a long time to hang a long time the fish muscle soft and flexible. After a period of time after hardening, that is dead after the death. It is straight for some time and then gradually become soft, known as the solution is caught in the low temperature season, IQF frozen aquatic product fish caught in the high temperature season, the beginning of the fish and the duration of a long time. Fatigue struggling after the death of the fish less than the ventilated or immediately killed the fish stiff start and duration is short. After the catch, IQF frozen aquatic product the fish at the lower temperature begin to start and last for a long period of time, so it is very important to keep the ice fresh or cool after catching the fish.
(B) autolysis stage autolysis stage refers to the muscle from stiff to completely softening process. It is generally considered that the protein of muscle tissue gradually decomposes under the action of its own protein to produce low-level peptide and amino acid results, so called autolysis. But now more tend to think that the stiffness of the muscle protein in a long time in the contraction of tension and gradually fragile as well as the results of the fracture.
(C) the stage of corruption is the result of bacteria in the breeding of bacteria. Life of the body surface of the fish, gills, esophagus and other parts are with a certain amount of bacteria after the death of these bacteria gradually proliferate and invade the muscle tissue so that the fish after the self-dissolved into the corruption stage, into the corruption phase of the time sooner or later, IQF frozen aquatic product the main decision The size of the aquatic species, the season, IQF frozen aquatic product the preservation of the temperature and the initial degree of bacterial contamination. General upper and middle fish, small fish than the bottom of the fish, large fish easy to corrupt shellfish and shrimp and crabs than fish is easy to corrupt, IQF frozen aquatic product the preservation of high temperature than the preservation of the temperature is easy to corruption.