Why are some frozen shrimp red and some black?

The freezing process is different:Salt-frozen shrimp are frozen separately and then packaged together, and there is no glue between the shrimp and shrimp, while frozen shrimp are frozen together by freezing in water, so there is a big difference.

Secondly, the difference between salt-frozen shrimp and frozen shrimp is also the difference in eating methods, first of all, salt-frozen shrimp is relatively easy to digest, but it is not suitable for cooking because it is too salty, while frozen shrimp is different, with a good taste and easy to cook, and salt-frozen shrimp is best washed and then boiled, because direct cooking will produce a lot of salt, and eating more high-salt food is not good.

Precautions for frozen prawns

It is best not to drink a lot of beer when eating frozen shrimp, because that will produce too much uric acid, which can cause gout. Seafood should be eaten with dry white wine, because the fruit acids in it have the effect of sterilizing and removing fish.

When eating frozen shrimp, it should be cleaned, the shrimp line on the back of the shrimp is the waste of the shrimp that has not been excreted, if you eat it There is a muddy smell in the mouth, which affects the appetite, so it should be removed. The color is red, the body is soft, and the shrimp that turns around are not fresh, so try not to buy them. Spoiled shrimp must not be eaten.

This is due to the difference in the active components of astaxanthin and tyrosinase in shrimp.

The color of each box of salt-frozen shrimp is different. Because the astaxanthin and tyrosinase active ingredients in shrimp are not active at different temperatures, the color is also different. There is no clear theory to support which color is better for shrimp in the straight frozen state.

Because the shrimp will consciously secrete an oxygen supply hormone in the body after 3 hours out of the water, when frozen in the refrigerator, the hormone will gradually "separate and coagulate" due to the principle of "thermal expansion and cold contraction", causing the skin of the shrimp body to turn red.

There are also fresh prawns, which contain astaxanthin (that is, astaxanthin, because it is red when free, so it is also called astaxanthin), and when combined with protein, it is mostly cyan or blue-white. However, this binding is unstable, and with the extension of storage time or improper storage in business sales, the protein in shrimp will gradually hydrolyze into simple compounds under the action of enzymes and microorganisms.

Due to the change in protein, the properties of astaxanthin are also unstable, so it gradually decomposes and makes the shrimp body red.

How to thaw frozen shrimp:

If you want to achieve a good thawing of frozen shrimp so that its nutrients will not be excessively lost or destroyed, you want to soak in hot water directly in daily life, or quickly rinse it under tap water in order to save time, which is easy to lose the nutrients of shrimp.

Therefore, when thawing frozen shrimp, master certain scientific methods, such as rinsing the shrimp under tap water with very small droplets, or sprinkling some salt in the frozen shrimp, which can achieve good thawing without destroying its nutrients.

It should have been left with hot water, right?

Probably spoiled! It is not recommended to eat it. Or throw it away! During the pandemic. I'm afraid of eating problems! So.

Please give me five minutes to help you out.

Do not wash the shrimp you buy, as this will affect the preservation and taste. Put it directly into the bottle, stuff it up, close the lid and put it in the refrigerator to freeze, the colder the better. This can be kept for a little longer, especially if the shrimp are bought too much.

When eating, the fastest way is to use scissors to cut it from the middle, and if you don't have a drink bottle at home, you can use a lunch box, disposable plastic or metal. Note: Do not wash shrimp, the colder the freezing temperature, the better. You can also divide the newly bought shrimp into several portions and put them in a crisper or plastic bottle, then fill them with tap water, put them in the freezer compartment of the refrigerator, and take them out to thaw when you use them.

It is best to eat the thawed shrimp all at once, and do not freeze it in the refrigerator again, which is easy to blacken. Hope mine is helpful to you.

The shrimp is not thawed and then frozen, in this case it is easy to turn black.

If the frozen shrimp is not refrigerated at a low enough temperature during transportation or storage, the shrimp will thaw, and after thawing, the refrozen shrimp head will turn red.

The appearance of raw shrimp with red heads is generally due to improper storage methods and substandard refrigeration temperatures. For example, many frozen shrimp entering China through the border trade channel will have red heads, and when the border trade goods are cleared at the Sino-Vietnamese border port, there will be several hours when the shrimp are transported in a normal temperature environment, and there is no cold chain.

Especially in the hot summer, when the outside temperature is high, frozen shrimp can be easily thawed. After a long time of thawing, the shrimp head is still red after being frozen.

There are also some shrimp that have been stored for too long or are stored in cold storage at a temperature that does not meet the standard will also have red heads. Once the red head appears, the quality of the shrimp is affected, which is an irreversible process.

Once the raw shrimp has a red head, it will be difficult for the dealer to deal with it, and the sales will be blocked, and the serious ones will even be smashed in the hands of the dealer and cannot be sold.

Although white shrimp red heads have a great impact on dealers, in fact, raw shrimp red heads are not a difficult problem to solve. It is only necessary to ensure low temperature during transportation and refrigeration, and do not take off the cold halfway to prevent the raw shrimp from thawing, and there will be no red-headed shrimp.

The cyan one is normal, and after the high temperature, there is a kind of shrimp called red pigment in the shrimp, so the cooked shrimp is red, and the normal shrimp should be cyan, so the red shrimp is generally not too fresh, and when breathed in excess, the temperature rises and is red, which also means local local attenuation. There are two types of jelly: green and red. This is its variety, and of course the nutrition is not the same.

Shrimp varieties include "sea soul", green shrimp, cooked shrimp, frozen shrimp, cooked anchovy shrimp, red shrimp, lobster tail and other famous products.

Shrimp are rich in nutrients. Shrimp contains 20 percent protein. It is one of the foods with a high protein content.

It is several times or even ten times more than fish, eggs and milk. It contains essential amino acids as compared to fish. Proline is not high, but it is a balanced protein**.

In addition, shrimp also contains glycine. The higher the amino acid content, the sweeter the shrimp will be.

Compared to fish and poultry, shrimp is lower in fat and contains almost no animal sugars as an energy source. Shrimp is high in cholesterol and rich in taurine, which can lower serum cholesterol in people. Rich in trace elements such as potassium, iodine, magnesium, phosphorus and vitamin A.

It is also rich in minerals such as potassium, iodine, magnesium, phosphorus, vitamin A, aminophylline and other ingredients, and its meat is soft and easy to digest, making it an excellent food for the weak who need aftercare after illness.

Shrimp is rich in magnesium, magnesium has an important regulatory effect on heart activity, can protect the cardiovascular system, it can reduce blood cholesterol levels, prevent arteriosclerosis, and at the same time can also enlarge coronary arteries, which is beneficial for the prevention of hypertension and myocardial infarction. Dried shrimp has a strong effect through milk and is rich in phosphorus, calcium, especially for children, pregnant women.

Shrimp is a crustacean, and its exoskeleton contains an orange-red pigment, also called astaxanthin, which is a type of carotenoid. After this pigment is combined with the protein, it will turn to yellow, orange, purple, green, blue and other colors due to the difference in protein, when the protein is destroyed or the protein is separated from the pigment, the color will change back to orange-red, and the shrimp will turn red when cooked due to the denaturation of the protein. In addition to heating, strong acids, concentrated alcohol, concentrated brine, and heavy metal ions can denature proteins, so uncooked shrimp can also change color when impregnated with salt, wine, etc.

Ways to preserve prawns.

First of all, we prepare some mineral water bottles, not too big, not too small, ordinary mineral water bottles will do. In this way, this bottle is about 600ml, which is just enough to hold the prawns that can be eaten once, and it can be made just enough to make one serving without wasting.

Then we wash the shrimp twice, mainly to wash the sand in the shrimp. If the size of the shrimp bought back is different, then we have to separate the large and small ones and place them separately. The large shrimp is stewed in oil, and the shrimp of the shrimp is boiled, and the method is different.

Then we put the shrimp into the bottle one by one, and we put the shrimp head in first, taking care not to prick the hand. A bottle is full, but not too full, and some water should be filled, and the water should not be full, but the shrimp should be completely submerged.

Finally, put the bottle of shrimp in the refrigerator freezer and store it, it is still very delicious for a year, and it is no different from live shrimp. Take it out at any time when you want to eat it, thaw it in water, and when it is completely melted, cut open the bottle, take out the prawns, and start cooking.

When you buy goods in your life, you will inevitably encounter a lot of things, you will not understand, such as buying some prawns on weekdays, you will also meet some ice shrimp, frozen shrimp, but when you see shrimp, the appearance of shrimp is different, some shrimp appearance is red, some shrimp appearance is cyan, this is also according to the variety of some shrimp is different, or some shrimp is processed in front of you, after processing, it will change color, And the green shrimp is one of his own, it itself is this species, so the difference between red shrimp and green shrimp is very normal, some red shrimp can be eaten directly, and some green shrimp can only be eaten after cooking.

The green is fresh.

The red ones are cooked or squeezed for a long time!

The varieties are not the same.

The red shell is generally harder.

Green is good, there is a thing called astaxanthin in the shrimp that shows red after high temperature, so the cooked shrimp are red, normal fresh shrimp should be cyan, so the red shrimp are generally not too fresh, in the case of excessive respiration, the temperature rises, only red, which also means that there is a slight local rot.

Benefits of Shrimp:

1. Shrimp is rich in nutrition, shrimp contains 20% protein, is one of the foods with high protein content, is several times or even more than ten times that of fish, eggs and milk, shrimp and fish meat, the essential amino acid valine is not high, but it is a nutritionally balanced protein**, in addition, shrimp contains glycine, the higher the content of this amino acid, the higher the sweetness of shrimp.

2. Compared with fish and poultry, shrimp has less fat content, and almost does not contain animal sugar as energy, the cholesterol content in shrimp is higher, and it is rich in taurine that can reduce human serum cholesterol, and shrimp is rich in potassium, iodine, magnesium, phosphorus and other trace elements and vitamin A and other components.

3. It is also rich in potassium, iodine, magnesium, phosphorus and other minerals and vitamin A, aminophylline and other ingredients, and its meat is soft and easy to digest, which is an excellent food for people who are weak and need to recuperate after illness.

4. Shrimp is rich in magnesium, magnesium has an important regulating effect on heart activity, can protect the cardiovascular system well, it can reduce the content of cholesterol in the blood, prevent arteriosclerosis, and at the same time can dilate the coronary arteries, which is conducive to preventing hypertension and myocardial infarction.

5. Shrimp has a strong lactation effect, and is rich in phosphorus and calcium, which is especially beneficial to children and pregnant women.