CATDOLL : CATDOLL: How to keep fish fresh

Question 1: How to use a refrigerator to preserve fish for long-term storage? The first choice is the quick freezing function of an air-cooled refrigerator. After rapid freezing, store it at low temperature.

For short-term storage, it is best to store at 0℃ in a zero-degree fresh-keeping room, ice room, or variable temperature room. The best preservation effect is when the temperature is close to 0℃ but not frozen.

Question 2: How to keep fish fresh? My method is to dry the fish, put it in a plastic bag, and then put some cold water in the bag, preferably enough to cover the fish. Then freeze it so that it will not dry out and become tough.

Question 3: How to keep the killed fish fresh? Mix it with salt and wine, and then you don't need to add salt when cooking. If conditions permit, you can choose to freeze it or vacuum pack it.

Question 4: How to preserve fish? Use a knife to cut a few holes in the fish belly, put some salt in it, and drip a few drops of low-alcohol liquor into the fish belly. It doesn't matter if there is more salt. I don't know where you are from, I'm from Jiangsu. When we eat fish, we pay attention to salty fish and light meat! !

Question 5: How can you keep a fish fresh after it has been killed? Method 1: There is a life and death line behind the nerves in the fish's eyes. When the fish leaves the water, the life and death line will immediately die, and the fish will die with it. When you buy a live fish and don't want to eat it for the time being, you can stick a wet paper on the eyes of the live fish, which can keep the fish alive for 3 to 5 hours after leaving the water.

Method 2: Freezing live fish: Freeze the fish directly in the refrigerator or freezer. Take it out and thaw it when you are ready to eat it. The fish will be as fresh as live fish.

Method 3 - Soaking in salt water after removing the internal organs: Without washing or scraping the scales, you can hollow out the fish's internal organs and soak them in 10% salt water. This will keep the fish fresh for several days without spoiling. Method 4 - Mustard preservation method: Apply an appropriate amount of mustard to the surface and inner cavity of the fish (if it has been gutted), or sprinkle it evenly around the container containing the fish, then place the fish and mustard in a sealed container. This will keep the fish fresh for 3 days without spoiling.

Method 5 - Hot water treatment: After removing the internal organs of the fresh fish, put it into boiling water (80-90 degrees), wait for a while and then take it out. At this time, the surface of the fresh fish has turned white. Store it on ice and the storage time can be extended by twice that of fresh fish that has not been treated with hot water.

Method 6 - Steam treatment: Clean the fresh fish, cut it into a shape suitable for cooking, and put it into a breathable plastic bag. Put the whole bag of fish in hot steam to sterilize and disinfect it, and it can be kept fresh for 2-3 days.

Question 6: How to keep fresh fish fresh? Please enlighten me. To keep fish fresh, we must first talk about the rotting of fish. There are several necessary conditions for fish rotting: 1. The fish is dead. 2. Under certain temperature and humidity conditions. 3. Enzymes and fungi act on the fish carcass. So, if you want to prevent fish from rotting, there are 3 corresponding measures: 1. Ensure the freshness of the fish. 2. Keep the fish in a low temperature environment, or dehydrate the fish quickly. 3. Effectively remove enzymes and fungi on the fish so that the enzymes and fungi cannot act on the fish carcass.

In fact, animals and plants have a similar characteristic, that is, they carry a lot of enzymes and fungi. These enzymes and fungi are symbiotic with the carrier during the growth period and natural preservation period of animals and plants. The two are interdependent and indispensable. Once the animals and plants that serve as carriers die or mature (stop growing), these enzymes and fungi begin to enzymatically engulf and engulf the carrier, causing the carrier to rot. This kind of decay is a very normal phenomenon in nature. If nothing would rot, then the world would have been full of garbage. Only by grasping and applying the laws of nature can people survive better. Making wine with fruits is to cleverly use the enzymes and fungi that are symbiotic on the fruit skin. Under certain conditions, these enzymes and fungi act on the carrier to produce wine.

Different types of fish have different tolerance to decay due to their different species and different growth environments. I don't have much contact with marine fish, but from the freshwater fish I have come into contact with, I have a clear feeling that farmed fish are more resistant to decay than wild fish. Specifically, the fish brought back from the farmed fish pond can be put directly into the refrigerator without processing, while wild fish, especially the crucian carp from Xiaolangdi, if they are not slaughtered cleanly in time and directly put into the refrigerator for freezing, when they are taken out for slaughter, you will find that the fish's stomach has rotted, and the smell of decay is very, very unpleasant. Even if the fish is not rotten, it is definitely not fresh, and no matter how much seasoning is added, it will not help. Moreover, this phenomenon is the worst in summer, and it is better in winter and other seasons when the temperature is low. It can be seen that the process of decay has already begun after the fish leaves the water and dies, and the higher the temperature, the faster the speed.

So the question is: Why are wild fish perishable while farmed fish are more resistant to decay?

It is not difficult to figure out this problem. We just need to think about the living environment of farmed fish and wild fish. Farmed fish are driven by economic benefits. People are afraid that the fish will grow slowly, have a bad appetite, get sick, and die. Therefore, in the fish feed, they naturally add a lot of appetizers, digestive aids, nutritional supplements, rapid fattening additives and even hormones. They also sprinkle some bactericidal and disinfectant drugs in the water. In this way, the fish grow faster, do not get sick, and the mortality rate is low, but the enzymes and fungi in the fish are naturally less, because the fish here don’t need them! Wild fish live in an environment of the survival of the fittest and fierce competition. If they want to survive, they must quickly strengthen their bodies and abilities. They need to eat quickly, digest quickly, and grow quickly. Therefore, a large amount of digestive enzymes accumulate in their bodies, especially in the gastrointestinal tract. There are also a large number of bacteria in the water where they live, and no one goes back to purify them. There are also a lot of bacteria that are beneficial to fish living in the fish's body. In this way, because wild fish carry a lot of digestive enzymes and various bacteria, wild fish will rot faster than farmed fish under the same conditions.

Once you understand the causes and processes of fish rotting, it will be much easier to consider the issue of keeping fish fresh. I have figured out a set of methods for preserving wild fish, for your reference only:

1. Kill the fish in time. This is a crucial step. After returning from fishing, no matter how late it is or how tired you are, you must kill the fish and clean them carefully. The purpose is to completely remove the digestive enzymes and bacteria on the fish. If there are too many fish, at least remove the fish's internal organs and clean the fish to prevent the enzymatic action of the fish's digestive enzymes. Of course, if the fish you bring back are alive and you have the conditions to keep them alive, that's another matter.

2. Refrigerate. After slaughtering and cleaning the fish, if you need to eat it the next day or within a short period of time, it is best to refrigerate it. Refrigeration can keep the fish fresher, while freezing can destroy the nutritional tissue of the fish, making it stale, unpalatable, and unnutritious. Even if you just remove the internal organs, refrigerate the fish at 0 degrees for no more than 24 hours. Of course, the enzymatic process of wild fish that have not been slaughtered will also be slow when refrigerated......>>

Question 7: If you don’t eat the fish right away after you buy it, how should you preserve it? If you don’t eat the fish right away after you get it home, you must clean it thoroughly (remove the gills, etc.) and leave the internal organs in the body. Then store it in the freezer so that the meat is still fresh and tender the next time you eat it. If you don’t clean it thoroughly and store it in the refrigerator, the fish will smell fishy the next time you eat it.

Question 8: How to keep the slaughtered fish fresh? Generally, it is recommended to use fresh fish as soon as possible. If you really want to preserve it, there is one way to keep it fresh for a short period of time. After killing the fish, remove the blood from the internal organs, wash it clean and put it in the refrigerator. It is recommended to eat it within 48 hours, and the freshness will not change much.

The most common way is to put it directly into the freezer, where it can be stored for about a week, but it cannot be stewed or steamed. Braised fish or dry-fried fish is recommended.

Question 9: How to keep fish fresh longer? There are many methods to preserve fish, such as vacuum packaging, packaging with deoxidizers, and packaging filled with carbon dioxide. These methods can effectively inhibit bacterial proliferation and prevent lipid oxidation, but they are not very effective in inhibiting the autodigestion of fish.

What is digestion? It turns out that after an animal dies, even if it is stored in an anaerobic environment, the glycogen in its body tissues is still broken down, and adenosine triphosphate (ATP) also begins to break down. As ATP decreases at an accelerated rate, the muscles contract and the body stiffens. Generally, fish begin to stiffen within about 7 hours after death, and the duration of stiffness is often shorter than that of mammals, only lasting about 5 to 22 hours. After the stiffness period, the muscles gradually become soft, and this change is called autodigestion. The autodigestion phenomenon occurs because the muscle tissue contains oxygen and the muscle protein changes. Even if the muscle is stored aseptically, autodigestion is still going on. Therefore, prolonging the stiffness time of the body and thus maximally controlling the autodigestion can greatly improve the preservation effect of fish meat.

To this end, researchers from Asahi Kasei Industries in Japan invented a method of injecting alkaline solution into the fish body and then sealing it to preserve it. The specific steps are as follows.

1. Inject an alkaline solution with a pH value of 7 to 12 into the body of a live fish. In order to improve work efficiency and allow the alkaline solution to quickly penetrate the fish body, use multiple syringes at the same time, inject small amounts into multiple locations, and focus on injecting into the internal organs.

The water-soluble inorganic alkaline substances suitable for the present invention include methyl carbonate, sodium carbonate, sodium bicarbonate, potassium pyrophosphate, sodium pyrophosphate, sodium nitrite, potassium nitrite, etc. The organic alkaline substances include sodium acetate, calcium propionate, sodium propionate, sodium citrate, sodium malate, sodium benzoate, etc.

The concentration of the alkaline aqueous solution is 1 to 20% by weight.

2. Place the fish injected with alkaline aqueous solution into a container made of non-permeable material and add inert gas such as CO2, N2 to seal it.

The inert gas in this article does not refer to chemical properties, but refers to gases that do not cause fish to deteriorate, such as helium, argon, hydrogen, carbon dioxide, nitrogen, methane, ethane, etc. However, from the perspective of economy and safety, it is better to use carbon dioxide and nitrogen.

There are many methods for filling the inert gas, such as the method of first evacuating the container and then filling the inert gas, the blowing displacement method, and the method of filling the inert gas after removing the oxygen in the container by absorbing with a deoxidizer. Generally, the higher the inert gas replacement rate, the more significant the composite effect of the inert gas and the alkaline solution. The present invention requires that the replacement rate is preferably 15% (volume).

The sealed container material used in the present invention should have good impermeability to the above-mentioned inert gases and oxygen. Materials that meet this requirement include metal, glass, and plastics such as polyvinyl alcohol resin, vinylidene chloride resin, polyester resin, polyamide resin, etc. Plastic containers are most suitable from the perspectives of transparency, damage resistance, and cost.

As for fish, no matter whether it is freshwater fish or marine fish, as long as it is alive, it can be preserved using the method of the present invention.

The storage temperature is within the range of 5-10℃, within which it can be kept fresh for more than 10 days.

Examples:

A 2.5% sodium disodium phosphate aqueous solution (pH 8.5) was injected into the internal organs of the horse mackerel with four needles (two needles on each side of the fish body) and two needles (one needle on each side of the fish body). The injection volume for each needle was 0.5CC, for a total of 3CC. The fish that had not died after the injection was placed in a composite film container made of polypropylene film (20μ)-ethylene-vinyl acetate copolymer saponified film (17μ)-polyethylene film (60μ). Then, carbon dioxide gas was blown in to replace the air in the container, and then it was sealed. About 10 minutes after sealing, the fish died of suffocation. The container with the fish was placed in a refrigerator and stored at a temperature of +3°C.