CATDOLL : CATDOLL: Is salmon the same as trout?

Is salmon trout?

Salmon is salmon. It is different from red snapper. Therefore, salmon is not rainbow trout.

Salmon is a type of marine fish belonging to the genus Salmon and the family Salmonidae in the order Salmoniformes. It usually lives in the Atlantic and Pacific Oceans, and is also produced in small quantities in Japan.

Rainbow trout is a species of freshwater fish in the genus Rainbow Trout, subfamily Salmoninae, order Salmoniformes. It usually lives in North America, the west coast of the Pacific Ocean, Heilongjiang and other places.

Difference in nutrients

Salmon is a type of marine fish, while rainbow trout is a type of freshwater fish. The main components of both are water, protein, fat, minerals and vitamins, but the content of unsaturated fatty acids in marine fish is higher than that in freshwater fish. Therefore, the nutritional value of salmon is higher than that of rainbow trout.

Difference in eating methods

Salmon can be eaten raw, made into sushi, fried, stewed in soup, stewed in porridge, etc. It can also be cooked like Chinese food.

Common cooking methods for rainbow trout include stewing, making porridge, frying, etc.

No, these two are different. You can go to the market and see that these two are completely different things.

Strictly speaking, rainbow trout is not salmon. Red trout is a sedentary species that lives in fresh water and does not migrate across salinity levels, while salmon is a species or population that needs to migrate between sea and fresh water.

Rainbow trout killed the vacuum or washed the vacuum

Rainbow trout kill the vacuum.

Soak the slaughtered fish meat in 8% NaCl solution at 20℃ for half an hour, remove and dry, put into a vacuum plastic bag, and evacuate. Precool the rainbow trout in the vacuum bag to 2℃, and then cool the rainbow trout to a storage temperature between -0.8℃ and -2.0℃ according to the continuous temperature change program, and maintain the storage temperature to achieve ultra-freezing storage of rainbow trout. The rainbow trout meat will not be frozen during storage, and the storage time can be up to 3 days.

Other ways to preserve rainbow trout

The main preservation methods for rainbow trout include low temperature preservation, ionizing radiation preservation, gas preservation, etc. A good preservation method needs to meet two conditions: one is to effectively prevent the reproduction and corruption of microorganisms, inhibit the biochemical reaction of enzymes and the oxidation of air, and meet food hygiene conditions. The other is to have the conditions and capabilities to handle large amounts of aquatic products in a timely and effective manner during production and transportation.

The most widely used and most effective method at present is the low-temperature preservation method. Other methods have some limitations and defects in terms of usage conditions and effects.

1. Low temperature storage

It includes two aspects: frozen storage and non-frozen storage at low temperatures, which are generally also called freezing and cooling. The bacteria that cause the spoilage of rainbow trout are mainly psychrophilic bacteria, whose minimum growth temperature is C7~-5℃ and the optimum temperature is 15~20℃. If it is lower than the optimum temperature, the growth of microorganisms will be inhibited; if it is lower than the minimum temperature, the growth will stop, and the growth of most bacteria will be slowed down at around 0℃.

In the low temperature range, a slight drop in temperature can significantly inhibit the growth of bacteria. At freezing temperatures, microorganisms are inhibited not only because of the effect of low temperature but also because the freezing of fish body water reduces water activity. In addition, the activity of various enzymes also weakens as the temperature drops. It is significantly inhibited at around -20°C and almost stops at below -30°C. Chemical changes after fish death, such as the oxidation reaction rate of fats, also significantly decreases as the temperature drops.

The low-temperature preservation methods of fresh rainbow trout include ice storage, cold seawater or cold brine preservation, slightly frozen preservation and frozen preservation.

2. Ice storage

A widely used preservation method. When ice melts, it absorbs a lot of heat to lower the temperature of the fish. The melted water can also wash away bacteria and dirt attached to the surface of rainbow trout. Fresh fish is often preserved with small ice cubes or ice flakes in a layer of fish and ice. The preservation time varies depending on the preservation, but is generally 1 to 2 weeks.

3. Cold seawater or cold salt water preservation

The fresh fish is preserved in cold seawater or cold salt water with a temperature of -1 to 1°C. This method is mainly used in fishing boats or canning factories. When used on fishing boats, the seawater or salt water must be cooled with ice or refrigeration equipment. If the fish body is immersed in cold seawater or cold salt water and cooled to 0°C, then taken out and preserved with ice, the effect will be better, and the preservation period is about 10 to 20 days.

4. Slightly frozen to keep fresh

The fish are circulated with low-temperature seawater or low-temperature salt water, and then slightly frozen for preservation. The slightly frozen temperature is -2 to -3°C, which freezes part of the water in the fish, and the preservation temperature is about -3°C. The preservation period can be up to 20 to 30 days.

The effects of cold seawater or cold brine preservation and partial freezing are better than ice storage because the temperature is lower than ice storage and the cooled fish body is firmer, which is convenient for transportation. The disadvantage is that it can cause the fish body to fade and the salt content in the fish meat to increase; at the same time, the seawater or brine mixed with fish blood, mucus and other dirt is easy to produce foam and pollution.

5. Frozen storage

Also known as frozen storage, fresh rainbow trout is first frozen in a freezing device and then placed in a low-temperature cold storage. The temperature at which fresh rainbow trout begins to freeze is -0.5 to -2°C. From the beginning of freezing to around -5°C, more than 80% of the water in the muscle tissue is frozen.

Fresh rainbow trout is usually frozen by quick freezing, that is, it must pass through the maximum ice crystal formation zone of 0 to -5°C within 30 minutes. The storage temperature after freezing is generally required to be lower than -18°C, and a storage temperature of -30°C or even lower can also be used.

6. Gas storage

Gas preservation is mainly used for fruits, vegetables, and meat, and has also been studied for the preservation of rainbow trout. This is also a preservation method combined with low-temperature preservation. The gas used is a mixture of carbon dioxide and oxygen, sometimes with nitrogen as an inert filler, to replace air in a low-temperature warehouse or container for the preservation of rainbow trout. Its quality and shelf life are better and longer than using low-temperature preservation alone.

The preservation effect of gas storage on rainbow trout may be due to the fact that carbon dioxide interferes with certain functions of the cell enzyme system, thereby inhibiting the metabolism of bacteria. In addition, carbon dioxide dissolved in water reduces the pH value of the fish body, which is also conducive to inhibiting the growth of bacteria. The solubility of carbon dioxide increases at low temperatures, and the use of higher concentrations of carbon dioxide combined with low temperatures has a better preservation effect.

During gas preservation, the distribution of fish bacteria species changes from the originally dominant Gram-negative bacteria to Gram-positive bacteria, thereby inhibiting the fish spoilage bacteria and reducing the odor produced by spoilage.